KR20150099381A - tomography apparatus and method for reconstructing a tomography image thereof - Google Patents

Abstract

Disclosed is a computer tomography apparatus which comprises a data obtaining part obtaining a first image and a second image which are partial images by using data obtained from each of a first angle section corresponding to a first point, and a second angle section corresponding to a second point and facing the first angle section by CT scanning a moving object, and obtaining first information presenting amount of movement of the object by using the first image and the second image; and an image reconstruction part reconstructing a target image presenting the object on a target point based on the first information.

Description

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tomographic imaging apparatus and a tomographic image reconstruction method using the tomographic imaging apparatus,

The present invention relates to a tomographic apparatus and a tomographic image reconstruction method therefor.

The medical imaging device is a device for acquiring the internal structure of an object as an image. The medical image processing apparatus is a non-invasive examination apparatus, which captures and processes structural details in the body, internal tissues and fluid flow, and displays them to the user. A user such as a doctor can diagnose the health condition and disease of the patient by using the medical image outputted from the medical image processing apparatus.

A CT (Computed Tomography) apparatus is an example of a device for irradiating an X-ray to a patient and photographing the object.

A CT (Computed tomography) apparatus, which is a tomographic imaging apparatus among medical image processing apparatuses, can provide a cross-sectional image of a target object and the internal structure of the target object (for example, kidneys, lungs, etc.) It is widely used for accurate diagnosis of diseases. Hereinafter, the medical image obtained by the tomographic apparatus is referred to as a tomographic image.

In acquiring a tomographic image, tomographic imaging of a target object is performed using a tomography apparatus to acquire raw data. Then, the tomographic image is reconstructed using the obtained RO data. Here, the data may be a projection data obtained by projecting the X-ray into a target object, or a sinogram which is a set of projection data.

For example, in order to acquire a tomographic image, an image reconstruction operation must be performed using a sinogram obtained by tomography. The restoration operation of the tomographic image will be described below in detail with reference to FIG.

1 is a view for explaining a CT image capturing and restoring operation.

Specifically, Fig. 1 (a) is a view for explaining a CT photographing operation of a computed tomography apparatus for performing CT photographing while rotating around a subject 25, and acquiring road data corresponding thereto. 1 (b) is a diagram for explaining a sinogram and a reconstructed CT image obtained by the CT imaging.

The computed tomography apparatus generates an X-ray and irradiates the X-ray to a target object, and an X-ray detector (not shown) detects the X-ray passing through the target object. The X-ray detector (not shown) generates data corresponding to the detected X-ray.

Specifically, referring to Fig. 1 (a), the X-ray generator 20 included in the computed tomography apparatus irradiates X-rays to the object 25. In the CT imaging, the X-ray generator 20 rotates about the object and acquires a plurality of row data 30, 31, and 32 corresponding to the rotated angle. Specifically, the first data 30 is acquired by sensing the X-ray applied to the object at the P1 position, and the second data 31 is acquired by sensing the state of the object applied to the object at the P2 position. Then, the X-ray applied to the object at the P3 position is sensed to acquire the data 32 in the third place. Here, the data may be projection data.

In order to generate a single-sided CT image, the X-ray generator 20 must rotate at least 180 degrees and perform a CT scan.

1 (b), a plurality of projection data 30, 31, and 32 obtained by moving the X-ray generator 20 at predetermined angular intervals as described in FIG. 1 (a) ) Can be combined to obtain a single sinogram 40. The sinogram 40 is a sinogram obtained by performing a CT scan of the X-ray generator 20 for one rotation, and the sinogram 40 corresponding to one rotation of the X- Lt; / RTI > The rotation of one week may be about half a turn or more or more than one turn, depending on the specifications of the CT system.

After filtering the sinogram 40, the CT image 50 is reconstructed by performing a filtered back-projection.

Generally, it takes 0.2 seconds or so for the X-ray generator 20 to rotate a half turn.

When an object to be CT is moved, movement of the object occurs during one week, and motion artifacts are generated in the reconstruction of the CT image due to the movement of the object.

FIG. 2 is a view for explaining motion artifacts present in a reconstructed CT image. FIG. 2 shows a CT image obtained by applying a full reconstruction method that performs image reconstruction using the acquired data obtained by rotating the object over 360 degrees.

2, when the motion artifacts are generated, the outermost edges 220 of the object 210 are not displayed clearly and superimposed on the restored CT image 200, and the CT images 200 The inner boundary 230 is blurred and displayed.

Such motion artifacts in the CT image deteriorate the image quality of the CT image, which degrades the accuracy of the reading and diagnosis in diagnosing the disease by the user reading the image by the doctor.

Therefore, when a moving object is CT, it is most important to restore the CT image with minimized motion artifacts.

An object of the present invention is to provide a tomographic apparatus and a tomographic image reconstruction method capable of reducing motion artifacts that may occur in reconstructed tomographic images.

It is another object of the present invention to provide a tomography apparatus capable of restoring a tomographic image in which motion artifacts are reduced while minimizing the amount of radiation irradiated to a human body, and a tomographic image reconstruction method therefor.

The tomographic apparatus according to an embodiment of the present invention may include a tomographic imaging apparatus that tomographic images of a moving object are acquired and acquired in each of a first angular interval and a second angular interval corresponding to a second angular interval corresponding to the first angular interval, A data acquiring unit acquiring a first image and a second image, which are partial images, using the data, and acquiring first information indicating a motion amount of the object using the first image and the second image; And an image restoration unit for restoring, based on the first information, a target image indicating the target object at a target time point.

In addition, each of the first angle section and the second angle section may have a value less than 180 degrees.

Also, the first information may be obtained by comparing only the first image and the second image.

In addition, at least one of the size, position, and shape of the object included in the image may be different in the first image and the second image.

In addition, in the target image, the degree of motion correction of the target object included in the target image may be changed according to the target time.

Also, when the target point corresponds to an intermediate angle between the first angular interval and the second angular interval, the target image may be motion-compensated more accurately than when the target point does not correspond to the intermediate angle .

In addition, the first information may be information indicating the amount of movement of the surface forming the object.

The first information is information corresponding to a motion vector field between the first image and the second image, and information indicating the amount of motion of the surface forming the object corresponding to each time point is .

Also, the motion vector field can be measured using non-rigid registration.

In addition, the first information may have a linear relationship between the amount of motion corresponding to the motion vector field and the time point of time.

The data acquiring unit acquires the first image and the second image using the RO data acquired by tomography in one-week angular intervals of less than one rotation, and the first angular interval and the second angular interval are respectively And may be a start interval and an end interval of the periodic angular interval.

The image reconstruction unit may reconstruct the target image by using a plurality of projection data corresponding to a plurality of views, which are RO data obtained by rotating and rotating less than one rotation.

The first information may include motion information on all directions of the surface of the object imaged in the first image and the second image.

The image restoring unit may predict the amount of motion of the object at the target point based on the first information, and may restore the target image based on the predicted amount of motion.

The image reconstruction unit may reconstruct the target image by warping a plurality of partial images representing a part of the target object based on the first information.

In addition, the image reconstruction unit may warp an image grid for imaging the object based on the first information, and may restore the target image using the waved image grid.

In addition, the image reconstruction unit may restore the target image by warping a pixel corresponding to the data acquired by the tomography, based on the first information, in a back projection process.

The image reconstruction unit may restore the target image by performing a backprojection operation based on the position of the voxel waved by waving the center of the voxel representing the target based on the first information.

The tomography apparatus according to an embodiment of the present invention further includes a user interface unit for receiving a relationship between the amount of movement and the time of the object in the first information through a user interface screen for setting the first information can do. The data acquiring unit may acquire the first information based on the relationship.

In addition, the data acquiring unit may perform the tomography at 180 degrees + additional angular intervals according to a half reconstruction method using a rebinned parallel beam.

Also, the data acquiring unit acquires projection data corresponding to 180 degrees + additional angle section, and the additional angle may have a value of approximately 30 to 70 degrees.

Further, the tomography apparatus according to an embodiment of the present invention may further include a display unit for displaying a user interface screen including a menu for setting the target time point.

Further, the tomography apparatus according to an embodiment of the present invention further includes a display unit for displaying a screen including at least one of the first information, the target point, the target image, and a user interface screen for setting the first information .

In addition, when the projection data corresponding to the 180 degree + additional angle, which is a periodic angular section around the object, is obtained, the data acquiring unit acquires projection data corresponding to the first angle included in the first additional angle section of the one- Wherein the first image and the third image are acquired in each of the second angular interval and the fourth angular interval included in the last additional angular interval of the one-period angular interval, And acquire the first information based on a motion amount between the first image and the second image, and a motion amount between the third image and the fourth image.

The data acquiring unit may acquire at least one of the first image, the second image, and the target image by performing the tomography according to at least one of an axial scan method and a helical scan method.

In addition, the tomographic apparatus according to an embodiment of the present invention includes a display unit for displaying a medical image; And a user interface unit set as a region of interest of the medical image. The data acquiring unit may extract at least one surface included in the ROI, and the data acquiring unit may acquire at least one surface included in the ROI, based on the extracted surface orientation, the first angle section, the second angle section, An end point of a first angular section, and an end point of the first angular section, and the target point, acquiring the first image and the second image in each of the first angular section and the second angular section corresponding to the setting, The first information indicating the amount of motion of the object may be obtained using the first image and the second image.

The data acquiring unit may acquire the first angular section, the second angular section, the first viewpoint, the second viewpoint, the start point of the one-week angular section, the end of the one-week angular section, Point, and the target point of time.

In addition, the subject may comprise at least one of heart, abdomen, uterus, brain, breast and liver.

Further, the object includes a heart represented by a surface, and the heart may include at least one tissue having a different brightness value in a predetermined area.

The data acquisition unit may perform the tomography according to at least one of an axial scan method and a helical scan method.

A tomographic apparatus according to an embodiment of the present invention is a tomographic imaging apparatus that tomographs a moving object and displays a first image and a second image corresponding to a first image and a second image corresponding to the same portion of a surface forming the object, A data acquiring unit acquiring first information indicating a motion of the object using the first image and the second image; And an image restoration unit for restoring the target image using the first information.

In addition, the first image and the second image may be reconstructed partial images using data obtained in the first angular interval and the second angular interval that are less than 180 degrees.

Also, the first information may be obtained by comparing only the first image and the second image.

In addition, the first image and the second image may differ in at least one of the size, position, and shape of the object included in the image.

The first information is information corresponding to a motion vector field between the first image and the second image, and information indicating the amount of movement of the surface forming the object corresponding to each time point is .

The data acquiring unit may perform the tomographic imaging in one week angular interval less than one rotation, the first viewpoint corresponds to a start interval of the one-period angular interval, and the second viewpoint corresponds to an end interval of the one- .

The image restoring unit may restore the target image indicating the target object at the target point between the first point and the second point of view based on the first information.

In addition, in the target image, the degree of motion correction of the target object included in the target image may be changed according to the target time.

Also, when the target point corresponds to an intermediate angle between the first angular interval and the second angular interval, the target image may be motion-compensated more accurately than when the target point does not correspond to the intermediate angle .

The data acquiring unit may reconstruct the target image using a plurality of projection data corresponding to a plurality of views, which are RO data obtained by performing tomography and rotating in less than one rotation.

Also, the first information may be information indicating the amount of movement of the surface of the object during the first time point to the second time point.

A tomographic image reconstruction method according to an embodiment of the present invention is a tomographic image reconstruction method in which tomographic images of a moving object are acquired in each of a first angular interval and a second angular interval corresponding to a second angular interval corresponding to a first angle, Acquiring a first image and a second image, which are partial images, using the generated data; Acquiring first information indicating a motion amount of the object at a time point using the first image and the second image; And reconstructing, based on the first information, a target image indicating the target object at a target time point.

In addition, each of the first angle section and the second angle section may be less than 180 degrees.

The acquiring of the first information may include acquiring the first information by comparing only the first image and the second image.

In the first image and the second image, at least one of a size, a position, and a shape of the object included in the image may be different.

In addition, in the target image, the degree of motion correction of the target object included in the target image may be changed according to the target time.

Also, when the target point corresponds to an intermediate angle between the first angular interval and the second angular interval, the target image may be motion-compensated more accurately than when the target point does not correspond to the intermediate angle .

In addition, the first information may be information indicating the amount of movement of the surface forming the object.

The first information is information corresponding to a motion vector field between the first image and the second image, and information indicating the amount of movement of the surface forming the object corresponding to each time point is .

In addition, the motion vector field may be measured using non-rigid registration.

In addition, the first information may have a linear relationship between the amount of motion corresponding to the motion vector field and the time point of time.

The obtaining of the first image and the second image may include acquiring the first image and the second image using the RO data obtained by performing tomographic imaging in the one-period angular section of less than one rotation, The first angular interval and the second angular interval may be a start interval and an end interval of the periodic angle interval, respectively.

In addition, the step of restoring the target image may include restoring the target image using a plurality of projection data corresponding to a plurality of views, which are RO data obtained by performing tomographic imaging and rotating in less than one rotation can do.

The first information may include motion information on all directions of the surface of the object imaged in the first image and the second image.

The step of restoring the target image may include a step of predicting the amount of motion of the object at the target point based on the first information and restoring the target image based on the predicted amount of motion .

The restoring the target image may include restoring the target image by warping a plurality of partial images representing a part of the target object based on the first information.

The restoring of the target image may include warping an image grid for imaging the object based on the first information, and restoring the target image using the warped image grid Step < / RTI >

The restoring of the target image may include restoring the target image by warping a pixel corresponding to the data obtained by the CT photographing based on the first information in a back projection process.

The restoring of the target image may include the steps of: warping a center of a voxel representing the target object based on the first information, performing a back projection operation based on the position of the wobbled voxel, and restoring the target image Step < / RTI >

The method of reconstructing a tomographic image according to an embodiment of the present invention may further include the step of receiving information on the amount of movement and time of the object through the user interface screen for setting the first information. In addition, the acquiring of the first information may acquire the first information based on the relationship.

The acquiring of the first image and the second image may include performing the tomography at 180 degrees + additional angular intervals according to a half reconstruction method using a rebinned parallel beam can do.

Further, the method may further include acquiring projection data corresponding to 180 degrees + additional angle section, and the additional angle may have a value of approximately 30 to 70 degrees.

In addition, the tomographic image restoration method according to an embodiment of the present invention may further include displaying a user interface screen including a menu for setting the target time point.

Further, the tomographic image restoration method according to an embodiment of the present invention may further include displaying a screen including a user interface screen for setting the first information, the target point of view, the target image, and the first information have.

The acquiring of the first image and the second image may include acquiring projection data corresponding to 180 degrees plus an additional angle around the object, The first image and the third image are acquired in each of the first angular interval and the third angular interval included in the angular interval, and the second angular interval and the second angular interval included in the last additional angular interval of the one- And acquiring the second image and the fourth image in each of the four angular intervals. The acquiring of the first information may include acquiring the first information based on the amount of motion between the first image and the second image and the amount of motion between the third image and the fourth image can do.

According to another aspect of the present invention, there is provided a tomographic image reconstruction method including: displaying a medical image; And setting an area of interest of the medical image. The acquiring of the first image and the second image may include extracting at least one surface included in the region of interest and extracting at least one of the first angle section and the second angle section based on the extracted surface direction, Wherein at least one of a start point of a one-week period, an end point of a one-week period, and a target time point is set, and in each of the first angle interval and the second angle interval corresponding to the setting, And acquiring the first image and the second image.

Also, in the tomographic image reconstruction method according to the embodiment of the present invention, considering the movement direction of the object, the first angular section, the second angular section, the first viewpoint, the second viewpoint, The end point of the one-week period, and the target point of time.

In addition, the subject may comprise at least one of heart, abdomen, uterus, brain, breast and liver.

Further, the object includes a heart represented by a surface, and the heart may include at least one tissue having a different brightness value in a predetermined area.

A method for reconstructing a tomographic image according to an embodiment of the present invention includes tomographic imaging of a moving object, generating a first image and a second image corresponding to a first image and a second image, respectively, which represent the same part of a surface forming the object, Acquiring an image; Obtaining first information indicating a motion of the object using the first image and the second image; And restoring the target image using the first information.

In addition, the first image and the second image may be reconstructed partial images using data obtained in the first angular interval and the second angular interval that are less than 180 degrees.

The acquiring of the first information may include comparing only the first image and the second image to acquire the first information.

In addition, the first image and the second image may differ in at least one of the size, position, and shape of the object included in the image.

The first information is information corresponding to a motion vector field between the first image and the second image, and information indicating the amount of movement of the surface forming the object corresponding to each time point is .

In the tomographic image reconstruction method according to an embodiment of the present invention, the step of acquiring the first image and the second image may include the step of performing tomographic imaging in a one-period angular section of less than one rotation, And the second viewpoint may correspond to an ending section of the one-period angular section.

The step of reconstructing the target image may include reconstructing a target image representing the target object at the target point between the first point and the second point of view based on the first information.

In addition, in the target image, the degree of motion correction of the target object included in the target image may be changed according to the target time.

Also, when the target point corresponds to an intermediate angle between the first angular interval and the second angular interval, the target image may be motion-compensated more accurately than when the target point does not correspond to the intermediate angle .

In addition, the step of restoring the target image may include restoring the target image using a plurality of projection data corresponding to a plurality of views, which are RO data obtained by performing tomographic imaging and rotating in less than one rotation can do.

Also, the first information may be information indicating the amount of movement of the surface of the object during the first time point to the second time point.

The tomographic apparatus according to an embodiment of the present invention performs tomographic imaging of a moving object and generates a first partial image and a second partial image using a data obtained in each of a start angle section and an end angle section facing the start angle section, A data obtaining unit obtaining first information indicating a relationship between a motion amount and a time of a surface of the object corresponding to a motion vector field between the first partial image and the second partial image; And an image restoration unit for restoring, based on the first information, a target image indicating the target object at a target time point.

A tomographic apparatus according to an embodiment of the present invention is a tomographic imaging apparatus that tomographs a moving object and displays a first image and a second image corresponding to a first image and a second image corresponding to the same portion of a surface forming the object, A data acquiring unit acquiring first information indicating a motion of the object using the first image and the second image; And an image restoration unit for restoring, based on the first information, at least one of data required for half-recovery and an image obtained by projecting the filtered data back-filtered to restore the target image representing the object at the target time point .

The tomographic apparatus according to an embodiment of the present invention is a tomographic apparatus that tomographs a target object and obtains data obtained in each of the first angular section and the second angular section corresponding to the second angular section and corresponding to the first angular section, Acquires additional information, which is information on motion generated in the object during the tomography, and acquires additional information, such as the first image, the second image, and the additional information A data obtaining unit obtaining first information indicating a motion amount of the object; And an image restoration unit for restoring, based on the first information, a target image indicating the target object at a target time point.

1 is a view for explaining a CT image capturing and restoring operation.
FIG. 2 is a view for explaining motion artifacts present in a reconstructed CT image.
Figure 3 is a schematic diagram of a typical CT system 100.
4 is a diagram illustrating the structure of a CT system 100 according to an embodiment of the present invention.
5 is a diagram showing a configuration of a communication unit.
6 is a block diagram illustrating a tomography apparatus according to an embodiment of the present invention.
7 is a block diagram showing a tomography apparatus according to another embodiment of the present invention.
8 is a view for explaining reconstruction of a tomographic image according to half reconstruction.
9 is a diagram for explaining a scan mode applied to tomographic imaging.
10 is a view for explaining a beam shape of an X-ray emitted to a target object.
11 is a view for explaining the operation of the tomography apparatus according to the embodiment of the present invention.
12 is another view for explaining the operation of the tomography apparatus according to the embodiment of the present invention.
13 is a view for explaining the motion of the object.
14 is another drawing for explaining the motion of the object.
15 is a view for explaining an operation of restoring a target image.
16 is a view for explaining target point setting.
Fig. 17 is another diagram for explaining target point setting. Fig.
18A is a diagram for explaining restoration of a target image indicating a moving object.
FIG. 18B is a diagram for explaining motion artifacts that may occur in restoring a target image representing a moving object. FIG.
18C is a diagram for explaining a target object represented by a three-dimensional tomographic image.
19 is a diagram for explaining the measurement of the amount of motion of the object.
20A is another drawing for explaining an operation of restoring a target image.
20B is a view showing the restored target image.
21A is another drawing for explaining an operation of restoring a target image.
21B is a view showing a restored target image.
22 is a diagram for explaining a warping operation used for restoring a target image.
23 is another diagram for explaining a warping operation used for restoring a target image.
24 is another drawing for explaining the operation of restoring the target image.
25 is a view showing a restored target image.
26 is another diagram for explaining the motion amount measurement.
FIG. 27 is a view for explaining motion artifacts existing in the reconstructed tomographic image. FIG.
28 is another view for explaining motion artifacts present in the reconstructed tomographic image.
29 is a view showing a user interface screen displayed in the tomography apparatus according to the embodiment of the present invention.
30 is another drawing showing a user interface screen displayed in the tomography apparatus according to the embodiment of the present invention.
31 is another diagram showing a user interface screen displayed in the tomography apparatus according to the embodiment of the present invention.
32 is a flowchart illustrating a tomographic image reconstruction method according to an embodiment of the present invention.
33 is a flowchart illustrating a tomographic image reconstruction method according to another embodiment of the present invention.

Brief Description of the Drawings The advantages and features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments described hereinafter with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terms used in this specification will be briefly described and the present invention will be described in detail.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term, not on the name of a simple term, but on the entire contents of the present invention.

When an element is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements as well, without departing from the spirit or scope of the present invention. Also, as used herein, the term "part " refers to a hardware component such as software, FPGA or ASIC, and" part " However, 'minus' is not limited to software or hardware. The " part " may be configured to be in an addressable storage medium and configured to play back one or more processors. Thus, by way of example, and not limitation, "part (s) " refers to components such as software components, object oriented software components, class components and task components, and processes, Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and variables. The functions provided in the components and "parts " may be combined into a smaller number of components and" parts " or further separated into additional components and "parts ".

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly explain the present invention in the drawings, parts not related to the description will be omitted.

As used herein, the term "image" may refer to multi-dimensional data composed of discrete image elements (e.g., pixels in a two-dimensional image and voxels in a three-dimensional image). For example, the image may include a medical image or the like of the object obtained by the tomography apparatus.

In the present specification, a tomography image is an image obtained by tomography of a target object in a tomography apparatus, and may mean an image imaged using projected data after irradiating a light beam such as an x-ray to a target object. Specifically, the "CT (Computed Tomography) image" may mean a composite image of a plurality of x-ray images obtained by rotating the object about at least one axis and photographing the object.

As used herein, an " object "may include a person or an animal, or a portion of a person or an animal. For example, the subject may comprise at least one of the following: liver, heart, uterus, brain, breast, organs such as the abdomen, and blood vessels. The "object" may also include a phantom. A phantom is a material that has a volume that is very close to the density of the organism and the effective atomic number, and can include a spheric phantom that has body-like properties.

As used herein, the term "user" may be a doctor, a nurse, a clinical pathologist, a medical imaging specialist, or the like, and may be a technician repairing a medical device.

A CT system or the like can provide a cross-sectional image to a target object. Therefore, the advantage of being able to express the internal structure of a target object (for example, elongation, lung, etc.) have.

Specifically, the tomography system 100 may include all tomography devices such as CT (computed tomography) devices, OCT (Optical Coherence Tomography), or PET (positron emission tomography) CT devices.

Hereinafter, the CT system will be described as an example of the tomographic imaging system 100. FIG.

The CT system can obtain a relatively accurate sectional image with respect to a target object by, for example, acquiring image data of 2 mm or less in thickness at several tens or hundreds of times per second. Conventionally, there has been a problem that only the horizontal section of the object is expressed, but it has been overcome by the appearance of the following various image reconstruction techniques. Three-dimensional reconstruction imaging techniques include the following techniques.

- SSD (Shade surface display): A technique to represent only voxels having a certain HU value by the initial 3D image technique.

- MIP (maximum intensity projection) / MinIP (minimum intensity projection): A 3D technique that represents only those with the highest or lowest HU value among the voxels that make up the image.

- VR (volume rendering): A technique that can control the color and transparency of voxels constituting an image according to a region of interest.

- Virtual endoscopy: A technique capable of endoscopic observation on reconstructed 3-D images using VR or SSD techniques.

- MPR (multi planar reformation): An image technique that reconstructs into other sectional images. It is possible to reconstruct the free direction in the direction desired by the user.

- Editing: Several techniques for organizing surrounding voxels to more easily observe the region of interest in the VR.

- VOI (voxel of interest): A technique that expresses only the selected region by VR.

A computed tomography (CT) system 100 in accordance with an embodiment of the present invention may be described with reference to FIG. The CT system 100 according to an embodiment of the present invention may include various types of devices.

Figure 3 is a schematic diagram of a typical CT system 100. Referring to FIG. 3, the CT system 100 may include a gantry 102, a table 105, an X-ray generator 106, and an X-ray detector 108.

The gantry 102 may include an X-ray generating unit 106 and an X-ray detecting unit 108.

The object 10 can be placed on the table 105. [

The table 105 can be moved in a predetermined direction (e.g., at least one of up, down, left, and right) in the CT photographing process. In addition, the table 105 may be tilted or rotated by a predetermined angle in a predetermined direction.

Also, the gantry 102 may be inclined by a predetermined angle in a predetermined direction.

4 is a diagram illustrating the structure of a CT system 100 according to an embodiment of the present invention.

The CT system 100 according to an embodiment of the present invention includes a gantry 102, a table 105, a control unit 118, a storage unit 124, an image processing unit 126, an input unit 128, a display unit 130 ), And a communication unit 132. [

As described above, the object 10 may be located on the table 105. [ The table 105 according to an embodiment of the present invention can be moved in a predetermined direction (e.g., at least one of up, down, left, and right) and the movement can be controlled by the control unit 118. [

The gantry 102 according to an embodiment of the present invention includes a rotating frame 104, an X-ray generating unit 106, an X-ray detecting unit 108, a rotation driving unit 110, a data acquiring circuit 116, And may include a transmitter 120.

The gantry 102 according to an embodiment of the present invention may include a rotating frame 104 in the form of a ring that is rotatable based on a predetermined rotation axis RA. In addition, the rotating frame 104 may be in the form of a disk.

The rotating frame 104 may include an X-ray generating unit 106 and an X-ray detecting unit 108 arranged to face each other with a predetermined field of view (FOV). In addition, the rotating frame 104 may include an anti-scatter grid 114. Scattering prevention grating 114 may be positioned between the X-ray generating unit 106 and the X-ray detecting unit 108. 4, the rotating frame 104 includes one X-ray generating unit 106. However, the rotating frame 104 may include a plurality of X-ray generating units. When the rotation frame 104 includes a plurality of X-ray generation units, the rotation frame 104 includes a plurality of X-ray detection units corresponding to the plurality of X-ray generation units. Specifically, one X-ray generator 106 becomes one X-ray source. For example, if the rotating frame 104 includes two X-ray generators 106, it may be said to include a dual source. Hereinafter, when the rotating frame 104 includes one X-ray generating unit 106, one X-ray generating unit 106 included in the rotating frame 104 is referred to as a 'single source' When the rotating frame 104 includes two X-ray generators (not shown), two X-ray generators (not shown) included in the rotating frame 104 will be referred to as 'dual sources'. In addition, in the two X-ray generators forming the dual source, one X-ray generator will be referred to as a first source and the other X-ray generator will be referred to as a second source. The tomography system 100 in the case where one X-ray generation unit 106 is included in the rotation frame 104 is referred to as a 'single source tomography apparatus', and two X- ray generating unit is included in the tomographic imaging system 100 will be referred to as a 'dual source tomography apparatus'. In medical imaging systems, X-ray radiation reaching the detector (or photosensitive film) includes attenuated primary radiation, which forms useful images, as well as scattered radiation, which degrades the quality of the image . An anti-scatter grating can be placed between the patient and the detector (or photosensitive film), in order to transmit the majority of the radiation and attenuate the scattered radiation.

For example, the anti-scatter grating may be formed by strips of lead foil, a solid polymer material, a solid polymer, and a fiber composite material And the interspace material of the interlayer material may be alternately stacked. However, the form of the scattering prevention grating is not necessarily limited thereto.

The rotation frame 104 receives a drive signal from the rotation drive unit 110 and can rotate the X-ray generation unit 106 and the X-ray detection unit 108 at a predetermined rotation speed. The rotation frame 104 can receive a driving signal and power from the rotation driving unit 110 through a slip ring (not shown) in a contact manner. In addition, the rotation frame 104 can receive a driving signal and power from the rotation driving unit 110 through wireless communication.

 The X-ray generator 106 receives voltage and current from a power distribution unit (PDU) (not shown) through a slip ring (not shown) through a high voltage generator (not shown) . When the high voltage generating section applies a predetermined voltage (hereinafter referred to as a tube voltage), the X-ray generating section 106 can generate X-rays having a plurality of energy spectra corresponding to this predetermined tube voltage .

The X-ray generated by the X-ray generator 106 may be emitted in a predetermined form by a collimator 112.

The X-ray detector 108 may be positioned to face the X-ray generator 106. The X-ray detecting unit 108 may include a plurality of X-ray detecting elements. A single x-ray detector element may form a single channel, but is not necessarily limited thereto.

The X-ray detecting unit 108 detects an X-ray generated from the X-ray generating unit 106 and transmitted through the object 10, and can generate an electric signal corresponding to the intensity of the sensed X-ray.

The X-ray detector 108 may include an indirect method for detecting and converting radiation into light, and a direct method detector for detecting and converting the radiation directly into electric charge. An indirect X-ray detector can use a Scintillator. In addition, a direct-type X-ray detector can use a photon counting detector. A Data Acquisition System (DAS) 116 may be coupled to the X-ray detector 108. The electrical signal generated by the X-ray detector 108 may be collected at the DAS 116. The electrical signal generated by the X-ray detector 108 may be collected at the DAS 116 either wired or wirelessly. The electrical signal generated by the X-ray detector 108 may be provided to an analog / digital converter (not shown) via an amplifier (not shown).

Only some data collected from the X-ray detector 108 may be provided to the image processor 126 or only some data may be selected by the image processor 126 depending on the slice thickness or the number of slices.

The digital signal may be provided to the image processing unit 126 through the data transmission unit 120. The digital signal may be transmitted to the image processing unit 126 via the data transmission unit 120 in a wired or wireless manner.

The controller 118 according to an embodiment of the present invention can control the operation of each module of the CT system 100. [ For example, the control unit 118 includes a table 105, a rotation driving unit 110, a collimator 112, a DAS 116, a storage unit 124, an image processing unit 126, an input unit 128, 130, the communication unit 132, and the like.

The image processing unit 126 may receive data obtained from the DAS 116 (e.g., pure data before processing) through the data transmission unit 120 and perform pre-processing.

The preprocessing may include, for example, a process of non-uniformity of sensitivity correction between channels, a sharp decrease in signal intensity or a process of correcting loss of signal due to an X-ray absorber such as a metal.

The output data of the image processing unit 126 may be referred to as raw data or projection data. Such projection data can be stored in the storage unit 124 together with shooting conditions (e.g., tube voltage, shooting angle, etc.) at the time of data acquisition.

The projection data may be a set of data values corresponding to the intensity of the X-rays passing through the object. For convenience of explanation, a set of projection data simultaneously obtained with the same shooting angle for all the channels is referred to as a projection data set.

The storage unit 124 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (SD, XD memory, etc.), a RAM (Random Access Memory) SRAM (Static Random Access Memory), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory) And may include at least one type of storage medium.

Also, the image processing unit 126 can reconstruct the cross-sectional image of the object using the acquired projection data set. Such a cross-sectional image may be a three-dimensional image. In other words, the image processing unit 126 may generate a three-dimensional image of the object using a cone beam reconstruction method based on the acquired projection data set.

External inputs for X-ray tomography conditions, image processing conditions and the like can be received through the input unit 128. For example, the X-ray tomography conditions include a plurality of tube voltages, energy value setting of a plurality of X rays, selection of a photography protocol, selection of an image reconstruction method, FOV area setting, number of slices, slice thickness, Processing parameter setting, and the like. The image processing condition may include resolution of the image, setting of the attenuation coefficient for the image, and setting of the combination ratio of the image.

The input unit 128 may include a device or the like for receiving a predetermined input from the outside. For example, the input unit 128 may include a microphone, a keyboard, a mouse, a joystick, a touch pad, a touch pan, a voice, and a gesture recognition device.

The display unit 130 may display an X-ray image reconstructed by the image processing unit 126. FIG.

Transmission and reception of data, power, etc. between the above-described elements can be performed using at least one of wired, wireless, and optical communication.

The communication unit 132 can perform communication with an external device, an external medical device, or the like through the server 134 or the like. This will be described later with reference to Fig.

5 is a diagram showing a configuration of a communication unit.

The communication unit 132 may be connected to the network 301 by wire or wirelessly to perform communication with an external device such as the server 134, the external medical device 136, or the portable device 138. [ The communication unit 132 can exchange data with other medical devices in the hospital server or the hospital connected through the PACS (Picture Archiving and Communication System).

In addition, the communication unit 132 may perform data communication with an external device or the like according to a DICOM (Digital Imaging and Communications in Medicine) standard.

The communication unit 132 can transmit and receive data related to diagnosis of the object through the network 301. [ Also, the communication unit 132 can transmit and receive medical images and the like acquired from other medical devices 136 such as an MRI apparatus and an X-ray apparatus.

Further, the communication unit 132 may receive the diagnosis history or the treatment schedule of the patient from the server 134, and may utilize it for clinical diagnosis of the patient. The communication unit 132 may perform data communication with the user 134 or the portable device 138 of the patient as well as the server 134 and the medical device 136 in the hospital.

In addition, information on the abnormality of the equipment and the quality management status information can be transmitted to the system administrator or the service person through the network, and the feedback can be received.

6 is a block diagram illustrating a tomography apparatus according to an embodiment of the present invention.

6, the tomographic apparatus 600 according to an embodiment of the present invention includes a data acquiring unit 610 and an image reconstructing unit 620.

The tomographic apparatus 600 may be included in the CT system 100 described in FIGS. 3 and 4. FIG. Further, the tomographic apparatus 600 may be included in the medical device 136 or the portable device 138 described in FIG. 5, and may operate in connection with the CT system 100. Specifically, the tomographic imaging apparatus 600 may be any medical imaging apparatus that reconstructs an image using data acquired using light beams transmitted through a target object. That is, the tomographic apparatus 600 may be any medical imaging apparatus that reconstructs an image using projection data obtained using light beams transmitted through a target object. Specifically, the tomographic apparatus 600 may be a computed tomography (CT) apparatus, an optical coherence tomography (OCT), or a positron emission tomography (PET) -T apparatus. Therefore, the tomographic image obtained by the tomographic apparatus 600 according to the embodiment of the present invention may be a CT image, an OCT image, a PET image, or the like. In the drawings referred to below, a CT image is attached as a tomographic image as an example. Further, the tomographic apparatus 500 may be an MRI apparatus. 6, the data acquisition unit 610 and the image reconstruction unit 620 shown in FIG. 6 may correspond to the image processing unit 126 (FIG. 4) of FIG. 4. In the case where the tomography apparatus 600 is included in the tomography system 100 described with reference to FIG. 1, ).

The data obtaining unit 610 obtains first information indicating a motion of the object with respect to time by taking a tomographic image of the object. Specifically, the object may include a predetermined organ. Specifically, the subject may comprise at least one of heart, abdomen, uterus, brain, breast and liver. For example, an object may include a heart represented by a surface. Here, the heart may include at least one tissue having different brightness values within a predetermined region.

In addition, the data acquisition unit 610 rotates less than one rotation around the object, and performs tomography to acquire raw data. Here, the raw data may be projection data acquired by irradiating the radiation to a target object, or a sinogram which is a set of projection data. Also, raw data may be an image generated by filtered backprojection of projection data or a sinogram. Specifically, when the X-ray generating unit 106 emits an X-ray to a target object at a predetermined position, the X-ray generating unit 106 refers to a viewpoint or direction of the object. Projection data is acquired data corresponding to one view, and a synonym means data acquired by sequentially arranging a plurality of projection data.

Specifically, when the X-ray generator 106 rotates around a moving object and emits a cone beam, the data acquiring unit 610 acquires data corresponding to the cone beam, The data can be rearranged into data corresponding to the parallel beams. The first information can be obtained by using the data corresponding to the parallel beams. Here, the conversion of the cone beam into a parallel beam is referred to as rebinning, and the first information can be obtained by using the data corresponding to the parallel beam. Revision of the cone beam will be described in detail below with reference to FIG.

Specifically, the data obtaining unit 610 obtains data obtained in each of the first angle section and the second angle section corresponding to the first angle section and the second angle section corresponding to the first angle section, To acquire the first image and the second image. Then, the first information indicating the amount of motion of the object during the first time point to the second time point is obtained.

The image restoring unit 620 restores the target image representing the target object at the target point based on the first information.

Here, the first information is information indicating the amount of motion of the object in time. Specifically, the first information may be information indicating a movement of a surface forming a target object at a time point. The first information will be described in detail below with reference to FIG.

Specifically, the data obtaining unit 610 obtains the first image using raw data obtained in the first angular interval corresponding to the first point of time, calculates a first angle corresponding to the second angle, And acquires the second image using the RO data obtained in the second angle interval in the conjugate angle relationship. Here, the 'first angular interval' or the 'second angular interval' refers to a partial angular interval included in one angular interval less than one rotation. Specifically, the first angular interval and the second angular interval may have values less than 180 degrees. Also, the first image and the second image are partial images. The data acquisition unit 610 acquires information indicating the motion of the object using the first image and the second image. Specifically, the data obtaining unit 610 obtains first information indicating the amount of motion of the object during the first time point to the second time point. Here, the amount of motion may be a difference between at least one of a shape, a size, and a position between a predetermined object included in the first image and a predetermined object included in the second image, which is generated due to movement of the object.

The first information will be described in detail below with reference to FIG. 12 and FIG.

Then, the image restoring unit 620 can restore the target image indicating the target object at the target point. Here, the target point of time may be set by the image restoring unit 620 itself or may be set to a predetermined value input from the user. Also, the target time point may be a time point between the first time point and the second time point. The setting of the target time point by the user will be described in detail below with reference to FIG.

The specific operation of the tomographic imaging apparatus 600 will be described in detail below with reference to Figs. 7 to 19.

7 is a block diagram showing a tomography apparatus according to another embodiment of the present invention. 7, the data acquisition unit 710 and the image reconstruction unit 720 correspond to the data acquisition unit 610 and the image reconstruction unit 620 of FIG. 6, respectively, .

Referring to FIG. 7, the tomographic apparatus 700 includes a data obtaining unit 710 and an image restoring unit 720. The tomographic apparatus 700 may further include at least one of a gantry 730, a display unit 740, a user interface unit 750, a storage unit 760, and a communication unit 770. The gantry 730, the display unit 740, the user interface unit 750, the storage unit 760, and the communication unit 770 included in the tomographic apparatus 700 are the same as those of the CT system 100 shown in FIG. The operation and configuration of the gantry 102, the display unit 130, the input unit 128, the storage unit 124, and the communication unit 132 are the same as those of the gantry 102, the display unit 130,

The data obtaining unit 710 obtains first information indicating a movement of the object with respect to time by taking a tomographic image of the object.

Specifically, the data acquiring unit 710 acquires a first image corresponding to the first viewpoint and a second image corresponding to the second viewpoint, by taking a tomographic image of the object. Then, based on the amount of motion between the first image and the second image, first information indicating the relationship between the amount of motion and the time of the object is acquired. Here, the first image and the second image may be reconstructed according to partial angle reconstruction (PAR). Specifically, since the first image and the second image are reconstructed using only the RO data obtained in the angular interval, the reconstructed image is not a complete image indicating the entire object, but an incomplete image partially representing the object. to be. In addition, an incomplete image partially representing a target object such as a first image and a second image may be referred to as a 'partial image' or a 'partial angle image'.

The first viewpoint corresponds to the acquisition point of the RO data acquired to restore the first image, and the second viewpoint corresponds to the acquisition point of the RO data acquired to restore the second image. For example, in the case where the raw data acquired to restore the first image is restored using the raw data acquired during the time interval from 0 to a, It may be the time point a / 2 which is the middle of the time interval. In the case of restoring the first image using the data obtained during the time interval from the b point to the c point, the first point of time is a time from the point b to the point c ((C + b) / 2) which is the middle of the interval.

The first image represents a target object at a first viewpoint, and the second image represents a target object at a second viewpoint.

The image restoring unit 720 restores the target image indicating the target object at the target point based on the first information. Specifically, the image restoring unit 720 restores the target image through motion correction of the object based on the first information. Specifically, the image reconstructing unit 720 can reconstruct a target image by warping an image representing a target object, an image grid for imaging a target object, or a voxel representing a target object.

Here, warping means adjusting the object included in the image to the state of the predicted object by changing the state of the object such as expansion, contraction, position movement, and / or shape of the object included in the image do. The image restoring operation of the image restoring unit 720 will be described below in detail with reference to FIGS. 13 to 31. FIG.

The gantry 730 includes an X-ray generator (106 in FIG. 4), an X-ray detector (108 in FIG. 4), and a data acquisition circuit Ray, and generates raw data corresponding to the detected X-ray.

Specifically, the X-ray generator 106 generates an X-ray. Then, the X-ray generator 106 rotates around the object and irradiates the object with the X-rays. Then, the X-ray detector 108 detects an X-ray passing through the object. Then, the data acquisition circuit 116 generates data corresponding to the detected x-ray.

Hereinafter, it is assumed that the X-ray generator 106 reconstructs one tomographic tomographic image using the acquired tomographic image data obtained by rotating the X-ray generator 106 less than a half turn or more, is called a half reconstruction method, The reconstruction of a single tomographic image using RO data obtained by rotating the unit 106 one rotation is referred to as a full reconstruction method. Hereinafter, the time or angle (or phase) at which the X-ray generator 106 rotates is referred to as 'one-week period' in order to acquire data necessary for reconstructing a single tomographic image. In addition, the 'one-week period of angular interval' may mean an angular interval in which the X-ray generator 106 rotates to acquire data necessary for reconstructing a single tomographic image. In addition, 'one-week period of angles' may mean a period of projection data necessary for restoring one cross-sectional tomographic image. In this case, it may be referred to as 'one-week period of projection data'.

For example, in a half-restore, one cycle is 180 degrees or more, and in a full restore, one cycle is 360 degrees. For example, in a half reconstruction using a revised parallel beam, one angular section of the projection data can be 180 degrees by adding a fan angle to 180 degrees. For example, if the pan angle is approximately 60 degrees, the one-week angular section of the projection data at half restoration may be approximately 180 + 60 = 240 degrees. Also, in the full restoration, the one-week angular interval may be approximately 360 + 60 = 420 degrees by adding a pan angle to 360 degrees.

Specifically, the first viewpoint and the second viewpoint may be time points or angular points included in one week. Also, each of the first image and the second image may be reconstructed using the RO data obtained in the first angular interval and the second angular interval, which are different intervals included in one angular interval.

The display unit 740 displays a predetermined screen. Specifically, the display unit 740 may display a user interface screen or a reconstructed tomographic image necessary for performing tomography. The user interface screen displayed on the display unit 740 will be described in detail with reference to FIGS. 29 to 31. FIG.

The user interface unit 750 generates and outputs a user interface screen for receiving a predetermined command or data from the user, and receives a predetermined command or data from the user through the user interface screen. Also, the user interface screen output from the user interface unit 750 is output to the display unit 740. Then, the display unit 740 may display a user interface screen. The user can view the user interface screen displayed through the display unit 740, recognize predetermined information, and input predetermined commands or data.

For example, the user interface unit 750 may include a mouse, a keyboard, or an input device including hard keys for a predetermined data input. For example, the user can input at least one of a mouse, a keyboard, and other input devices included in the user interface unit 750 to input predetermined data or commands.

In addition, the user interface unit 750 may be formed of a touch pad. Specifically, the user interface unit 750 includes a touch pad (not shown) coupled with a display panel (not shown) included in the display unit 740, Output the interface screen. When a predetermined command is inputted through the user interface screen, the touch pad detects the predetermined command and recognizes the predetermined command inputted by the user.

Specifically, when the user interface unit 750 is formed of a touch pad, when the user touches a predetermined point on the user interface screen, the user interface unit 750 senses the touched point. The detected information may be transmitted to the image restoring unit 720. Then, the image restoring unit 720 recognizes the user's request or command corresponding to the menu displayed at the detected point, and can perform the tomographic image restoration operation by reflecting the recognized request or command.

The storage unit 760 may store data obtained according to tomography. Specifically, it is possible to store at least one of projection data, which is raw data, and a sinogram. In addition, the storage unit 760 may store various data, programs, and the like necessary for restoration of a tomographic image, and may store a reconstructed tomographic image. In addition, the storage unit 760 may store various data necessary for acquiring the first information and the acquired first information.

The storage unit 760 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (SD, XD memory, etc.), a RAM (Random Access Memory) SRAM (Static Random Access Memory), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read- And an optical disc.

The communication unit 770 can perform communication with an external device, an external medical device, and the like. For example, the communication unit 770 is connected to an externally connected CT system or a tomography apparatus, and can receive the first image and the second image. Or data for restoring the first image and the second image. In this case, the data obtaining unit 710 receives data for restoring the first image and the second image or the first image and the second image transmitted through the communication unit 770, and based on the transmitted data, 1 information.

The tomography apparatus 600 and 700 according to the embodiment of the present invention can be applied to both partial angle reconstruction (PAR), full reconstruction, and half reconstruction. In addition, in the tomography apparatuses 600 and 700 according to the embodiment of the present invention, various scan modes are applied to obtain the first image and the second image. In addition, in the tomography apparatuses 600 and 700 according to the embodiment of the present invention, all the tomography according to the axial scan method and the helical scan method can be applied. Further, in the tomography apparatuses 600 and 700, an X-ray generating unit 106 for generating a light source having various radiation forms can be used.

When the object moves like a heart, it is necessary to acquire the log data by minimizing the time or angle corresponding to one week, so that motion artifacts existing in the reconstructed tomographic image can be reduced. The half-reconstruction method can reduce the motion artifacts more than the full-reconstruction method. Hereinafter, a half-reconstruction method is used for restoring the target image.

Hereinafter, an image restoration method, a scan mode, a scan method, and a radiation pattern of an x-ray beam, which is a light source, applicable to the tomographic apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS.

8 is a view for explaining reconstruction of a tomographic image according to half reconstruction. Specifically, Fig. 8A illustrates the rotation of the X-ray generator 106. Fig. 8 (b) shows a tomographic image reconstructed by the half-reconstruction method.

When the X-ray generator 106 emits a cone beam, which is a fan-shaped beam spreading fan-like at a predetermined position, ) * 2), and tomographic images can be reconstructed using the log data obtained at 180 degrees + (fan angle * 2). In addition, when the restoration operation is performed by converting the fan beam into a parallel beam, or when the X-ray generator 106 emits a parallel beam, the half restoration has a 180+ fan angle The tomographic image can be reconstructed using the data corresponding to the section. That is, when a cone beam is used, data as much as a fan angle is needed, as compared with a case where a tomographic image is reconstructed by using data acquired using a parallel beam. .

Specifically, when the shape of the beam is not the shape of the cone beam but is in the form of a parallel beam as described in FIG. 10 (b), the angle value to be additionally rotated is larger than the fan angle of the cone beam , And rotate 180 + a degrees in one week. For example, in the case where the fan angle is 60 degrees, data obtained from the angular section of 180 + 2a = 300 degrees is required for the cone beam, and 180 degrees for the angle section of 180 + a = 240 degrees when the parallel beam is used. Obtained data is needed. Therefore, when a parallel beam is used, a half restoration method can be performed with 180 + a = 240 degrees as one week.

FIG. 8A illustrates a case where a half beam is reconstructed using the data obtained from the 180 + fan angle = a period using a parallel beam as an example.

8 (a), when the X-ray generator 106 irradiates X-rays from the beam position 810 to the object 805, the X-ray detector 108 detects the X- It detects x-rays. The beam position 810 moves in a circle around the object and rotates by 180 + a, which is one cycle. Also, the sensing surface 820 also rotates in correspondence with the beam position 810. Specifically, the beam position 810 moves 180 degrees in the + Y axis to the -Y axis, and further moves by a a fan angle a to move to the 833 point.

In the half reconstruction method, one CT sectional image is reconstructed using the projection data acquired in the first a angle section 835, the intermediate angle section 837, and the last a angle section 836.

Referring to FIG. 8 (b), a tomographic image 870 reconstructed using RO data obtained by a half-reconstruction method is shown.

Here, since the x-ray is irradiated in the same direction toward the object in the first a-angle interval 835 and the last a-angle interval 836, the first a-angle interval 835 and the last a- Has the same view (veiw). Accordingly, the reconstructed target object region using the projection data acquired in the first a angle section 835 and the reconstructed target object region using the projection data obtained in the last a angle section 836 are the same.

In the case of a moving object, even if it is the same part of the object, if data is acquired at different points in time, the data is different due to the motion of the object. The state of the object in the first a angle section 835 differs from the state of the object in the last a angle section 836. [ Accordingly, the projection data acquired in the first a angle section 835 and the projection data obtained in the last a angle section 836 imaging the same object section as in the first a angle section 835 are used to perform imaging Motion artifacts may occur most severely at an object site.

Referring to FIG. 8B, it can be seen that movement artifacts are generated in the surface portions 882 and 883 representing the target object in the tomographic image 870 restored by the half-reconstruction method.

In contrast, in the half-reconstruction method, since the angle section for acquiring the projection data is small as compared with the entire reconstruction method, in the tomographic image 870 reconstructed by the half-reconstruction method, motion artifacts . For example, in the tomographic image 200 shown in Fig. 2, the outermost surface 230 of the object 210 is blurred, while in the tomographic image 870 shown in Fig. 8 (b) The outermost surface 881 of the target object 880 may be seen to be less blurred than the outermost surface 230 of the target object 210 in the tomographic image 200. [

Also, blurring is reduced in the inner surfaces 883 and 883 as compared with the tomographic image 200 shown in FIG. 2, and the motion artifacts of the reconstructed tomographic image 870 as a whole are reduced.

As described above, in the tomographic image 870 reconstructed by the half reconstruction method, motion artifacts may be reduced as compared with the tomographic image obtained by the total reconstruction method. That is, as the time required to acquire data necessary for reconstructing a single tomographic image is reduced, an image with reduced motion artifacts can be reconstructed. That is, as the time required to acquire the data required to reconstruct a single tomographic image is reduced, the temporal resolution can be increased and the amount of radiation irradiated to the patient can be reduced. In the tomographic apparatus according to the embodiment of the present invention and the tomographic image reconstruction method according to the embodiment of the present invention, the above-described whole reconstruction method or half-reconstruction method can be used.

In addition, the tomography apparatuses 600 and 700 according to the embodiment of the present invention can perform tomography according to various scan modes. The scan modes used in the tomography include prospective mode and retrospective mode, which will be described in detail below with reference to FIG. In addition, the tomography apparatuses 600 and 700 according to the embodiment of the present invention can perform tomography according to various scan methods. The scan method used in the tomographic scan is an axial scanning method and a helical scanning method, which will be described in detail with reference to FIG.

9 is a diagram for explaining a scan mode and a scan method applied to tomographic imaging. Specifically, FIG. 9A is a view for explaining tomographic imaging according to the axial scanning method. 9 (a) is a view for explaining tomographic imaging in a prospective mode. 9 (b) is a view for explaining tomographic imaging according to the helical scanning method. 9 (b) is a view for explaining a tomography according to a retrospective mode.

The scan mode can be distinguished depending on whether the heartbeat period of the patient to be imaged is constant or not. In addition, ECG gating can be used to acquire RO data used for image reconstruction. In FIG. 9, the table (105 in FIG. 4) is moved in the axial direction of the patient 905 and the tomography is performed as an example.

Referring to FIG. 9A, in an axial scanning method, an X-ray is irradiated in a state where the table (105 in FIG. 4) is stopped, the table is moved by a predetermined interval 901-902, And radiographic data is acquired by irradiating the X-ray during the predetermined section 922. FIG. The tomography apparatuses 600 and 700 according to the embodiment of the present invention can acquire at least one of a first image, a second image, and a target image by performing tomography using an axial scan method.

9 (a), in the case of a person having a constant heartbeat cycle, the electrocardiogram signal 910 is gated regularly by applying a prospective mode. The prospective mode automatically selects a predetermined section 921 at a time point t3 that is a predetermined time away from the R peak (911). Then, X-ray is applied to the object during the detected predetermined period 921 to acquire the log data. Then, the predetermined section 922 at the time t4, which is a predetermined time away from the subsequent R peak 912, is automatically selected. At this time, the X-ray is irradiated and photographed in the state where the table (105 in FIG. 4) is stopped, the table is moved again by a predetermined interval (901-902) do. As shown in FIG. 9A, the half-reconstruction method is an axial half reconstruction method in which the imaging is performed at predetermined intervals in the axial direction of the object, and the tomographic imaging apparatus 600 according to the embodiment of the present invention , 700 may be subjected to axial half recovery.

The data obtaining unit 710 restores the tomographic images 931 and 932 using the RO data obtained from the detected regions 921 and 922.

Referring to FIG. 9B, a helical scan method is a method of moving a table (105 in FIG. 4) from a time t = 0 to a time t = It is a shooting method. Specifically, the table (105 in FIG. 4) in which the patient 905 including the object is located is continuously moved at a constant speed for a predetermined time, and while the table is being moved, the X-ray is continuously irradiated to the object to perform imaging. Accordingly, the movement locus 950 of the X-ray light source becomes a helix shape.

Referring to FIG. 9 (b), when the heartbeat period of the heart is not constant as in the case of an arrhythmia patient, the regularity of the heartbeat cycle is decreased, so that periodic detection can not be performed uniformly as in the prospective mode . In this case, the electrocardiogram signal 960 is gated irregularly in a retrospective mode. The retro-spective mode acquires data by irradiating X-rays to an object in every period of the electrocardiogram signal or in a successive period of the period, and then selects partial periods for tomographic image reconstruction. That is, in the retro-spective mode, after the partial periods 961, 962 and 963 are detected by individually setting the partial periods to be used for image restoration by the user, the data obtained from the detected intervals are subjected to tomographic image restoration .

Specifically, in the retro-spective mode, imaging is continued by irradiating X-rays continuously from t = 0 to t = end, which is a constant time. In addition, the table (105 in FIG. 4) may be continuously moved at a constant speed for a predetermined time to perform tomography. In this case, the movement locus 950 of the X-ray source becomes a helix shape. As shown in FIG. 9 (b), a method of sequentially radiating X-rays while moving the table is referred to as a helical half reconstruction, and the tomographic apparatus according to the embodiment of the present invention 600, and 700, a spiral half restoration method may be applied.

As a specific example, in patients with irregular heartbeat cycles, a retrospective mode can be applied in a helical scan mode to perform tomography. Further, in the case of a patient having a constant heartbeat cycle, tomographic imaging can be performed by applying the prospective mode in the axial scan method. However, the present invention is not limited to this, and tomographic imaging may be performed by applying the prospective mode in the helical scanning mode, and tomographic imaging may be performed by applying the retrofocus mode in the axial scanning mode. 10 is a view for explaining a beam shape of an X-ray emitted to a target object. Specifically, FIG. 10A illustrates an example in which the X-ray generator 106 irradiates an X-ray in the form of a cone beam. 10 (b) shows an example in which the X-ray generator 106 irradiates X-rays in the form of a parallel beam.

10 (a), when the X-ray generator 106 moves along the locus 1010 and irradiates an X-ray at a predetermined position 1020, a cone shape 1030 is formed as shown in FIG. 10 X-ray is examined as a target.

Referring to FIG. 10B, when the X-ray generator 106 moves along the locus 1050 and emits an X-ray at a predetermined position 1060, as shown in FIG. 10B, Are examined as objects.

10B, when the X-ray generator 106 emits an X-ray in the form of a cone beam, the X-ray detector 108 rearranges the beam radiated in a conical shape, The beam can be rearranged in parallel on a plane 1080 connecting a row of X-ray generators 106 and a locus 1060 where the X-ray generator 106 is located. That is, the cone beam can be converted into a virtual parallel beam. In addition, when the cone beam is converted into a parallel beam and used, the X-ray generating unit 106 rotates further by the fan angle (a) in comparison with the parallel beam in the cone beam to acquire the row data. Specifically, when the fan angle = a, the X-ray generator 106 that emits the cone beam uses the data obtained in the angular interval of 180 + 2a to generate the parallel beam corresponding to the revolved parallel beam The data corresponding to the angular interval of 180 + a can be acquired.

As described with reference to Fig. 10, the tomographic apparatuses 600 and 700 according to the embodiment of the present invention can be applied to both a CT apparatus that emits a cone beam, or a CT apparatus that emits a parallel beam.

Hereinafter, for the sake of convenience of explanation, in the case of the half-reconstruction method, in order to acquire the projection data necessary to acquire one cross-section tomographic image, in the one-week angular section in which the X-ray generator 106 rotates, The additional angle section is called an additional angle section. In the above-described example, the additional angle is 2a when using a parallel beam that has been revived from the cone beam emitted from the X-ray generator 106, and the additional angle when using a parallel beam. When the parallelized beam is used, the X-ray generator 106 acquires the projection data corresponding to the 180 + a angular interval using the acquired data obtained by rotating the 180 + 2a angular section. In addition, when the section of the projection data obtained in order to reconstruct one cross-section tomographic image is regarded as one angular interval, the additional angle may mean the angular interval obtained by subtracting 180 degrees from one angular interval of the projection data. In the example described above, when the X-ray generator 106 emits a cone beam and rotated 180 + 2a angular intervals, the projection data corresponding to the 180 + a angular interval is acquired using the revised parallel beam , The angular interval of one projection period of the projection data is 180 + a, and the additional angle may be a in one-angular interval of the projection data.

Also, in the case of acquiring the first information and the target image by using the concave beam as a target and irradiating the object with a tomogram and using the revised parallel beam, the X- The one-week angular interval is 180 + 2 * fan angle = 180 + 2a, and the additional angle can be 2 * fan angle = 2a.

In the tomographic apparatus 700 according to the embodiment of the present invention, in acquiring the first image and the second image, a partial angle reconstruction is performed to reconstruct an image using the RO data acquired in the partial angle section . Specifically, each of the first image and the second image may be reconstructed using the RO data obtained in the first angular interval and the second angular interval, which are different intervals included in one angular interval. The acquisition of the first image and the second image according to the partial restoration will be described in detail below with reference to FIGS. 11 and 12. FIG.

Since the X-ray generator 106 rotates at a constant speed and performs tomography, the angle value is proportional to the time value. When the value of the predetermined angle section decreases, it is necessary to acquire data at a predetermined angle section The time required for the operation is reduced. Therefore, in the partial angle restoration method, the smaller the angle section used for restoring the partial angle image, the more the temporal resolution can be increased. Therefore, the first image and the second image, which are partial angle images, are images having high temporal resolution and almost no motion artifacts, and can be images that accurately represent a part of the object without blurring.

11 is a view for explaining the operation of the tomography apparatus according to the embodiment of the present invention.

Hereinafter, the case where the X-ray generator 106 rotates 180 degrees + additional angle in one angular interval and applies tomographic imaging will be described as an example by applying the half restoration method described with reference to FIG. As described above, the additional angle, which is an angle section excluding 180 degrees in the half restoration, can be changed according to at least one of the shape of the beam used, the CT system, and the product specification of the X-ray generator.

The X-ray generating unit 106 rotates 180 + 2a angles and emits a cone beam, and the data acquiring unit 710 acquires the cone beam, For example, projection data corresponding to the 180 + a angular interval using the data obtained by rotating the 180 + 2a angular section by the X-ray generating unit 106 do. In addition, in the drawings and detailed description that will be referred to below, in accordance with the angular interval of the projection data obtained using the parallelized beams, one-week angular interval is 180+ fan angle = 180 + a, a. < / RTI >

Referring to FIG. 11, a 180-degree angular interval 1120 including 180 degrees 1130, a / 2 degrees 1141, and a / 2 degrees 1145 around a target object 1110 is set as a one-week angular interval 1120 . The specific value of the fan angle a may vary depending on the CT system or the product specifications of the X-ray generator, and may have a value of about 50-60 degrees, for example.

Specifically, the first angle section 1142 and the second angle section 1146 may be angular sections included in the one-period angular section 1120, and may have a conjugate angle relationship, which is an angle opposite to each other. The angular difference between the two angular sections in the conjugate relationship is 180 degrees.

11, the first angle section 1142 may be the start section of the one-week angular section 1120, and the second angle section 1146 may be the start section of the one-week angular section 1120, Section.

If the first angle section 1142 and the second angle section 1146 have a mutually conjugate relationship, the view in the first angle section 1142 and the second angle section 1146 is the same, The surface of the object 1110 that is sensed when the object 1110 is sensed when the object 1110 is sensed in the second angular interval 1146 and the surface of the object 1110 sensed when the object 1110 is sensed in the angle interval 1142, ) Are the same.

For example, a = 60 degrees, and the X-ray generator 106 rotates to acquire data corresponding to the interval a = 60 degrees. The first image and the second image are acquired using the raw data obtained in the first angle section 1142, which is the first 60-degree section and the second angle section 1146, which is the last 60-degree section.

Here, since the X-ray generator 106 rotates at a constant speed and performs tomography, the angle value is proportional to the time value, and when the value of the predetermined angle section decreases, data is acquired at a predetermined angle section The time required for the operation is reduced.

As described above, the tomographic apparatus 700 uses the raw data obtained in the first angular section 1142 and the second angular section 1146, which are partial sections included within one week of the angular section, 2 partial image reconstruction (PAR) technique. That is, the tomographic apparatus 700 can restore temporal resolution and minimize motion artifacts by restoring an image using a relatively small angular section, as compared with a half reconstruction or full reconstruction. In the embodiment of the present invention, the amount of motion of the object can be measured more accurately by measuring the amount of motion of the object using the first image and the second image, which are partial angle images.

Since the target image is generated by motion-compensating the object at the target point by using the first information, which is the motion information including the accurately measured motion amount, the target image with high temporal resolution and minimized motion artifact can be restored . The tomographic apparatus and the tomographic image reconstruction method according to an embodiment of the present invention, which can minimize motion artifacts and increase time resolution, will be described in detail below with reference to FIG. 12 to FIG.

12 is another view for explaining the operation of the tomography apparatus according to the embodiment of the present invention.

Referring to FIG. 12, the first angle section 1211 and the second angle section 1211, which are included in the one-week angular section 1210 and have a relationship of a pair of angles, 1212 obtain data necessary for restoration of the first image and the second image, respectively. Specifically, the first angular interval 1211 may be a start interval within one-week angular interval 1210, and the second angular interval 1212 may be an end interval within one-week angular interval 1210 .

Specifically, the X-ray generator 106 rotates about the object 1201 and performs tomography to obtain projection data or sinograms, which are data corresponding to the first angle section 1211 have. Then, the tomographic image 1231 is reconstructed using the acquired tomographic image data.

Here, the raw data acquired in the first angular interval 1211 and the second angular interval 1212 may be data obtained by sensing x-rays irradiated to a target from a single source or a dual source. For example, when a single source is used to perform tomography, a single source may move through the first angular section 1211 and the second angular section 1212 to perform tomography.

As another example, when performing a tomography using a dual source, at least one of a first source and a second source included in the dual source may include at least one of a first angle interval 1211 and a second angle interval 1212 So that tomographic imaging can be performed. Specifically, the first source will rotate the first angular interval 1211 to acquire the data, and the second source will rotate the second angular interval 1212 to acquire the data. It is also possible that the first source rotates the first angular interval 1211 (or the first angular interval 2001 and the second angular interval 1212 (or the second angular interval 2005 of FIG. 20A) And the second source acquires at least a part of the angular interval of the one-week angular interval 1120 excluding the first angular interval 1211 and the second angular interval 1212 (e.g., (At least one of the third angular interval 2002, the fourth angular interval 2003, and the fifth angular interval 2004) to be described later with reference to FIG. For example, Filtered Back Projection, Iterative method, and the like can be used as a method of reconstructing a tomographic image in the tomography apparatuses 600 and 700 have.

The back projection method is a method in which projection data obtained in a plurality of directions (view) is added back to the pixel surface and added together to restore the image. Specifically, the back projection method can obtain an image similar to an actual image by using projection data in a plurality of directions. In addition, filtering may be additionally performed to remove artifacts existing in the reconstructed image and to improve image quality.

Filter retro-projection is an improved method of back-projection to remove artifacts or blurring that can occur in back projection. The filtered back projection method filters the RO data before performing the reverse projection, and restores the ROI image by backprojecting the filtered RO data.

Filtered Back Projection is the most widely used method in fault reconstruction, simple to implement, and effective in terms of computational complexity for image reconstruction. Filter back projection is a mathematical inverse transformation derived from radon transformation, which is a process of obtaining a sinogram from a 2D image. It is also relatively simple to extend a 2D image to a 3D image. Specifically, the filtering back projection method is a method of restoring an image by filtering the projection data using a Shepp and Logan filter, which is a type of high pass filter, and then performing a back projection.

Hereinafter, a case of reconstructing a tomographic image using Filtered Back Projection will be described as an example.

Referring to FIG. 12, the data obtaining unit 710 obtains the image 1231 by performing filtered back projection on the raw data obtained in the first angle section 1211. Specifically, the first angular interval 1211 and the second angular interval 1212 have values less than 180 degrees. In order to further clarify the surfaces 1235 and 1236 in the image 1231, it is possible to filter the image 1231 to acquire the finally reconstructed first image 1232. In particular, the first image 1232 may be an incomplete image reconstructed by partial angle reconstruction.

Specifically, in the case of using the revised parallel beam, when the one-period angular interval of the projection data is 180 + a, the additional angle a may be set to the fan angle. Specifically, the first angular interval 1211 and the second angular interval 1212 having an additional angle a may be set to approximately 30-70 degrees.

Specifically, the first angular interval 1211 and the second angular interval 1212 can be set to experimentally optimized values to obtain the first and second images having high temporal resolution, The time resolution in the two images, the product specifications of the tomographic imaging apparatus 700, and / or the image capturing environment. Here, the angular values of the first angular interval 1211 and the second angular interval 1212 may be in a trade off relationship with the temporal resolutions of the first and second images 1232 and 1242. The temporal resolution of the first image 1232 and the second image 1242 increases as the angular values of the first angular interval 1211 and the second angular interval 1212 become smaller. However, if the angular values of the first angular section 1211 and the second angular section 1212 become smaller, the surface portion of the object to be imaged also decreases. Therefore, the smaller the angle value of the first angle section 1211 and the second angle section 1212, the smaller the surface portion of the object for extracting the motion amount of the object, and the motion information may be relatively inaccurate.

Therefore, considering the time resolution of the first image 1232 and the second image 1242 and the accuracy of the motion information obtained through the first image 1232 and the second image 1242, 1211 and the second angular interval 1212 to the optimized values.

The data obtaining unit 710 obtains the image 1241 by projecting the filtered data obtained in the second angular interval 1212 back to the filtering. In order to further clarify the surfaces 1245 and 1246 in the image 1241, it is possible to filter the image 1241 to acquire the finally reconstructed second image 1242. In particular, the second image 1242 may be an incomplete image reconstructed by partial angle reconstruction.

In FIG. 12, two-dimensional tomographic images, for example, a first image 1232 and a second image 1242 are restored. A target object represented by a surface in a three-dimensional tomographic image has edges (for example, 1235 and 1236) as in the first image 1232 and the second image 1242 shown in the two- ).

12, when the first information is acquired using only the first image 1241 and the second image 1242, which are two-dimensional tomographic images, the first image 1241 and the second image 1242, (For example, compare 1235 and 1236 with 1245 and 1246) of the edges included in the image that are included in the image and represent the same surface of the object.

In addition, a three-dimensional tomographic image may be reconstructed, and a first and a second image, which are three-dimensional tomographic images, may be used. When the 3D tomographic image is reconstructed from the first image and the second image, the motion amount of the object is calculated by comparing the differences of the boundaries in the image included in the first image and the second image and representing the same surface of the object It is possible to grasp.

Here, the data obtaining unit 710 obtains a first image (a first image) using the RO data obtained by performing the tomographic scan according to the axial scan method or the helical scan described with reference to FIG. 9A, The first image 1241 and the second image 1242 can be acquired.

Also, the first image 1241 and the second image 1242 may be referred to as one partial image pair.

The data acquisition unit 710 may acquire the first image 1241 and the second image 1242 using the helical scan method described with reference to FIG. When a helical scan method is used, the first image and the second image can be obtained by dividing the projection data of a plurality of views projecting the same part of the object into a conjugate view sector.

Also, when the first image 1241 and the second image 1242 are referred to as one partial image pair, the first information may be acquired using a plurality of partial image pairs.

Specifically, in the spiral scanning method, since the projection data corresponding to the entire view is acquired, the projection data of the entire view is divided into a plurality of conjugate view sectors, and in each of the plurality of conjugate view sections, Images can be acquired. Accordingly, a plurality of pairs of partial images corresponding to a plurality of conjugate view sections can be obtained. Accordingly, the data obtaining unit 710 can obtain the first information using a plurality of pairs of partial image pairs. In this case, by using a plurality of pairs of partial images, motion of the object can be more accurately predicted for each of a plurality of conjugate view sections included in one angular interval of the first information.

In addition, the X-ray detector (108 in FIG. 4) includes a 2D detector array to obtain projection data corresponding to a plurality of rows at a time, and tomographic imaging is performed using a helical scanning method A plurality of path data for acquiring a plurality of partial image pairs in the same conjugate view standard imaging the same position or the same region of the object may be obtained. For example, when the table is moved in the z-axis direction to perform tomographic imaging of the axial section, it is possible to acquire a plurality of partial image pairs at the same z-axis position of the object.

Hereinafter, a case in which the table is moved in the z-axis direction as shown in FIG. 9 (b) to perform tomographic imaging of the axial section will be described as an example. Specifically, when tomography is performed using the helical scanning method, a plurality of raw data sets can be acquired for the same z-axis position (hereinafter, referred to as 'z-position') due to movement of the table For example, in the spiral scan method, the value of the helical pitch, which is the movement interval of the table, is set so that the table moves by k intervals of the detector's k columns. In this case, The projection data formed in the i + k-th column of the detector may be the same in the second rotation after shifting the table and the projection data formed in the first rotation by the helical pitch. Here, the second rotation is the rotation following the first rotation, A pair of partial image pairs are acquired using the projection data formed in the i < th > column in the first rotation, and the two At least one pair of partial image pairs can be obtained using the projection data formed at the (i + k) -th column of the detector in the (i) th rotation.

Alternatively, a pair of partial image pairs may be obtained by projection data formed in the i-th column in the spiral scanning method, and at least one pair of partial image pairs may be obtained by interpolating the projection data formed in the neighboring columns of the i-th column.

Accordingly, the data acquiring unit 710 can acquire a plurality of partial image pairs corresponding to the same z position by performing tomography using a helical scanning method. The first information can be obtained by using a plurality of partial image pairs. Specifically, when the amount of motion of the object is measured using a plurality of partial image pairs, the amount of motion of the object can be measured more accurately than when the amount of motion of the object is measured using one partial image pair, Hereinafter, the first image 1232 and the second image 1242 are two-dimensional tomographic images as shown in the drawing, and the surface of the object is a boundary in the image. As an example.

Referring to FIG. 12, the first image 1232 and the second image 1242 express the edges included in a predetermined portion of the object equally.

As described above, since the first angle section 1211 and the second angle section 1212 have a relationship of a pair of angles, the first image 1232 and the second image 1242 display the boundary of the same part of the object . Accordingly, when the first image 1232 and the second image 1242 are compared, the difference between the surfaces of the same part of the object included in the first image 1232 and the second image 1242 can be known, It is possible to grasp the degree of movement of the robot. When a moving object is tomographically photographed, at least one of a size, a position, and a shape of a target object included in the first image 1232 and the second image 1242 is different due to motion of the target object.

It is also possible to determine the position of the object in the direction perpendicular to the irradiation direction (for example, 1215) of the X-ray irradiated to the object in the first angular interval 1211 and the second angular interval 1212 Movement can be grasped more accurately than other directions.

In addition, using the raw data obtained at an angle interval of a relatively small angle, for example, a = 60 degrees, as compared with the half restoration or full restoration, the first image 1232 having high temporal resolution and low motion artifacts, And the second image 1242, it is possible to accurately measure the amount of motion of the object between the first point of view and the second point of view.

The data obtaining unit 710 obtains first information indicating that the object is moving with time based on the amount of motion between the first image 1232 and the second image 1242. [ The acquisition operation of the first information will be described in detail below with reference to FIG. 13 is a view for explaining the motion of the object. Specifically, FIG. 13A is a diagram for explaining a comparison operation between the first image and the second image. 13B is a diagram showing the amount of motion between the first image and the second image. 13 (c) is a diagram for explaining the first information.

Referring to FIG. 13A, the first image 1310 and the second image 1320 are partial images corresponding to the first image 1232 and the second image 1242 described in FIG. 12, respectively. However, for convenience of explanation, the case where the first image 1310 and the second image 1320 are complete images will be described as an example.

The first image 1310 and the second image 1320 illustrate a tomographic image of a moving object. 13A, at least one object 1311 and 1312 or 1321 and 1322 included in one image is represented by a circular object, as shown in the figure.

More specifically, the objects 1311 and 1312 included in the first image 1310 are compared with the objects 1321 and 1322 included in the second image 1320 to compare the amount of motion of the object. Then, according to the comparison result, the amount of motion of the object can be obtained as shown in the comparison image 1330. [

Referring to FIG. 13B, a motion vector representing the position difference value and direction of the compared surfaces can be obtained by comparing the surfaces showing the same part of the object included in the two images. Then, the motion vector can be used as the amount of motion of the object. Here, the information including the motion vectors and indicating the amount of motion of the predetermined portion of the object may be a motion vector field (MVF). In other words, the motion vector field (MVF) represents the amount of motion of the surface forming the object.

Here, the motion vector field is information obtained for motion extraction of the object, and it is possible to measure the amount of motion of the object using non-rigid registration. In addition, the amount of motion of the object can be measured using various motion measurement techniques such as rigid registration, optical flow, and feature matching.

Hereinafter, a case where a non-rigid registration method is used to obtain a motion vector field will be described as an example.

Specifically, a plurality of control points are set in an image grid of the first image 1310 or the second image 1330, and an optimal motion vector is calculated at each control point. Here, the motion vector is a vector including the direction and magnitude of the motion. Then, motion vectors at each of the control points are interpolated to obtain a motion vector field representing a motion vector in all the voxels. For example, B-spline free form deformation can be used as a method of interpolating a motion vector. In addition, an optimization technique can be used as a method of calculating an optimal motion vector at each control point. Specifically, the optimization technique updates the motion vector field by updating the motion vectors at the plurality of control points repeatedly, and updates the first image 1310 or the second image 1320 based on the updated motion vector field. The first image or the second image is compared with the second image 1320 or the first image 1310 before the warping, and when the similarity is the highest, the motion vector is calculated by terminating the iteration. Here, a similar degree can be a negative number of the sum of squared differences of two image brightness values to be compared.

Another method is to set control points on the surface of the object and compare the control points indicating the same point of the object in the first image 1310 and the second image 1320, Can be obtained. Specifically, the control points are matched to obtain a relative difference between the control points. Then, the relative difference value can be used as a motion vector at the current control point. Then, motion vectors at each of the control points are interpolated to obtain a motion vector field representing a motion vector in all the voxels. As in the above example, a B-spline free form deformation method can be used as a method of interpolating a motion vector. Referring to FIG. 13C, the one-week angular interval 1360, the first angular interval 1361, and the second angular interval 1362 correspond to the one-week angular interval 1210, The angular interval 1211, and the second angular interval 1212, the detailed description thereof will be omitted.

13C, in the graph showing the first information 1380, the x-axis represents time corresponding to one-week angular interval or one week, and the y-axis represents a weight value (W) corresponding to the motion amount .

Specifically, the first information corresponds to a motion vector field between the first image 1310 and the second image 1320, and may be information indicating the amount of motion of the object corresponding to the time point have. Specifically, the first information may be information indicating the amount of movement of the surface of the object corresponding to each time point. Here, 'time of each time' may be an arbitrary time point included in one period corresponding to one period of angular interval. Since one cycle time is a time required for the X-ray generator 106 included in the gantry 730 to rotate by one revolution, the rotation angle of the gantry may be used instead of the time point in the first information. In addition, the gantry 730 may include at least one X-ray generator 106 as described above. Specifically, the gantry 730 may comprise a single source and may include a dual source.

The first image 1310 obtained in the first angular interval 1361 which is the start period of the one-period angular interval 1360 is used as a reference image and the second image 1320 obtained in the second angular interval 1362 The motion amount of the first image 1310 can be matched to 0%, and the amount of motion of the second image 1320 can be matched to 100%. Hereinafter, the value of the motion vector field, which is the amount of motion between the first image 1310 and the second image 1320, is expressed as a weighting value. Also, the amount of motion may be the sum of absolute values of all motion vectors in the motion vector field. Also, the motion amount can be expressed in terms of a weight value.

13 (c), taking the case where the relationship between the weight W indicating the amount of motion of the object and the time has a simple linearity, for example, the weight and the time are shown in a section 1390 May have the form of a graph 1370. Alternatively, the shape of the graph 1370 corresponding to the first information may be arbitrarily defined by the user, or may be optimized and set in consideration of the object. For example, if the subject is a heart, the shape of the graph 1370 may have a non-linear shape depending on the movement state of the heart at the time of restoration.

Specifically, when the amount of motion and time of the object have a linear relationship, the data obtaining unit 710 obtains a motion vector between the zero motion vector field and the motion between the first image 1310 and the second image 1320 May be matched to the first weight and the second weight, respectively. Specifically, a zero motion vector field corresponds to a start point of a one-week angular section, and a motion vector field representing a motion amount between the first image 1310 and the second image 1320 corresponds to an angle And may correspond to the end point of the section. 13C, in the graph 1370 showing the first information 1380, the weight value 0 representing the zero motion vector field is the starting point (0 degree) of the one-week angular interval 1360 or a weight 1 representing a motion vector field representing a motion amount between the first image 1310 and the second image 1320 is matched at the time t = 0, and the weight 1 is 180 + a, which is the end point of the one- Point or t = end. Also, the case where the time and the weight have a linear relationship with each other is shown as an example.

Here, the first point of time t1 corresponds to the first image and the second point of time t2 corresponds to the second image. For example, assume that data is acquired for restoring the first image in the interval of 0 second to 0.03 second of 0.2 second corresponding to the angular interval 1360 of one week. Then, the first point of time may be a time point of 0.015 second as an intermediate time between 0 and 0.03 second. That is, when restoring a predetermined image using the RO data obtained in the predetermined time period, the time point corresponding to the predetermined image may be the middle point of the predetermined time period. The first image 1310 corresponding to the first viewpoint t1 corresponds to the view when the X-ray generator 106 looks at the object at a position corresponding to the first viewpoint t1 . The second image 1320 corresponding to the second time point t2 corresponds to the view when the X-ray generating unit 106 looks at the object at a position corresponding to the second time point t2 .

In the first information, when the weight value has a value between 0 and 1, the minimum weight value 0 is set to the motion amount at the point or point at which the size of the object is smallest within the one-week angular interval 1360 And a maximum weight value of 1 may correspond to a motion amount at a point or a point at which the object becomes largest within the one-week angular interval 1360.

Further, in the first information, the relationship between the amount of motion and time may be determined according to a quadratic relationship or a relationship modeled by statistical information.

For example, the motion pattern of an object can be statistically modeled. Specifically, if the subject is a heart, the movement of the heart may be statistically modeled and the shape of the graph 1370 in the first information region 1390 may be set to correspond to the modeled heart movement.

In the first information, the shape of the graph representing the movement pattern of the object may vary depending on the object. For example, if the subject is a whole heart, the shape of the graph in the first information may reflect the movement pattern of the whole heart. In addition, when the subject is a coronary artery included in the heart, the graph form of the first information may reflect the movement pattern of the coronary artery. In addition, even if the subject is a coronary artery included in the heart, the movement pattern may be changed according to the position of the coronary artery in the heart, and the graph form of the first information may be set differently according to the position of the coronary artery. Further, when the subject is a mitral valve (MV) included in the heart, the graph form of the first information may reflect the movement pattern of the mitral valve.

In addition, the movement pattern may be different for each partial region of the object to which the tomographic image is to be imaged. In this case, the first information may be acquired for each of the partial areas so as to reflect different motion patterns for the partial areas. In addition, motion compensation may be performed for each of the partial areas using the first information obtained differently for each of the partial areas, thereby restoring the target image representing the entire object. For example, if the subject is a heart, the movement pattern may be different in each of the left ventricle, right ventricle, left atrium, and right atrium. In this case, the first information is individually acquired in each of the left ventricle, the right ventricle, the left atrium, and the right atrium, motion compensation of the partial images of the left ventricle, right ventricle, left atrium, and right atrium is performed, Can be restored. Further, in the first information, the relationship between the amount of motion and time may be set by the user. For example, the user can set the shape of the graph 1370 in the section 1390 through the user interface unit 750. The setting of the first information through the user interface unit 750 will be described in detail below with reference to FIG.

In order to more accurately reflect the change in motion between the first image 1310 and the second image 1320 in the first information 1380, The motion variation of the object in the angular interval between the first angular interval 1361 and the second angular interval 1362 can be predicted by using the raw data acquired through the entirety of the first angular interval 1361 and the second angular interval 1362. [

For example, the data obtaining unit 710 obtains the estimated projection data obtained by forward projection of the restored target image using the first information 1380 at the target time, And compares the measured projection data obtained by the tomography. The data obtaining unit 710 may correct the first information 1380 so that an error between the predicted projection data and the measured projection data becomes small. As described above, the data obtaining unit 710 may repeatedly modify the first information 1380 so that the first information 1380 accurately reflects the motion of the object.

The image restoring unit 720 restores the target image corresponding to the target time point based on the first information.

14 is another drawing for explaining the motion of the object. 14, the X-ray generator 106 emits an X-ray in the form of a cone beam as shown in FIG. 4, but converts the X-ray into a parallel beam by rebinning the cone beam As an example. Therefore, in FIG. 14, the shapes of the beams irradiated in the first angular section 1411 and the second angular section 1412 are shown as parallel beams, and one angular section is 180 + a degrees.

14, when the X-ray generator 106 rotates around the object 1405, when performing tomography, the X-ray generator 106 rotates on a circular locus 1041, To examine the x-rays. Specifically, the X-ray generator 106 rotates around the object 1405 according to a half-reconstruction method and performs tomography. 14, the first angular interval 1411 and the second angular interval 1412 correspond to the first angular interval 1361 and the second angular interval 1362 in Fig. 13, respectively. The object 1405 shown in Fig. 14 may correspond to the object (for example, 1311 and 1321) described in Fig. 13 (a).

The object included in the first image obtained in the first angle section 1411 corresponding to the first point of time t11 and the object included in the second image obtained in the second angle section 1412 corresponding to the second point of time t15 By comparing the included objects and acquiring the amount of motion and the first information of the object, the size change of the object in the one-week angular interval 1410 can be predicted using the first information.

For example, at a first point of time t11 corresponding to the first angle section 1411, the object 1405 has a first size 1420, and the size of the object 1405 gradually increases with time, The object 1405 may have a second size 1430 at a second time point t15 corresponding to the angle section 1412. [

When the X-ray generator 106 rotates during the first angular interval 1411 and irradiates X-rays to the object, the X-rays are irradiated in the illustrated direction 1470 and exist in a direction parallel to the illustrated direction 1470 The surface of the object (e.g., 1451, 1452, 1453, 1454) is clearly sampled and imaged.

Thus, for a subject having a first size 1420 in the first image, the illustrated surfaces 1451 and 1452 are displayed, and for a subject having the second size 1430 in the second image, 1453 and 1454 are displayed.

The data acquiring unit 710 compares the first image and the second image to acquire the first information. Referring to part 1490 of FIG. 14, by comparing the surfaces 1451 and 1452 of the object having the first size 1420 with the surfaces 1453 and 1454 of the object having the second size 1430, The first information indicating the motion can be obtained.

Specifically, the 1 information is information representing the movement of the object with respect to time, and is a boundary of components parallel to the irradiation direction of the X-rays irradiated to the object 1405 in the first angle section 1411 or the second angle section 1412 and information indicating movement in all directions of an edge or a surface. Specifically, the surfaces 1451, 1452, 1453, and 1454 that are clearly imaged in the first image and the second image are displayed at a first viewpoint or a second viewpoint, or at the first viewpoint or the second viewpoint, Are disposed in a direction similar to the irradiation direction 1470 of the light emitting element. Thus, the first information includes motion information in all directions of the surfaces 1451, 1452, 1453, and 1454 that are clearly imaged in one image and the second image.

In addition, the first information can accurately indicate the movement of the object in the first direction 1480 perpendicular to the irradiation direction 1470 of the X-ray, more accurately than the movement of the object in a direction other than the first direction 1480. Specifically, the surface 1453 in the second image is the portion of the object corresponding to the surface 1451 in the first image, and the surface 1451 moves in the first direction 1480 by the first value 1481, (1453). The surface 1452 in the second image also moves to a portion of the object corresponding to the surface 1452 in the first image and the surface 1452 moves in the first direction 1480 by a second value 1482, 1454), as shown in FIG.

Although the irradiation direction 1470 of the x-rays in the first angular section 1141 and the second angular section 1142 is shown as one direction in Fig. 14, the X-ray generating section 106 may be arranged in the first angle & The irradiation direction 1470 of the X-ray in the first section is at least one of the irradiation direction of the X-ray at the 0 degree and the irradiation direction of the X-ray at the a degree, Direction. The first direction 1480 perpendicular to the irradiation direction 1470 of the x-rays in the first angular section and the second angular section corresponds to the irradiation direction 1470 of the x-rays in the first angular section and the second angular section, May include a predetermined range.

14, in the irradiation direction 1470 of the X-rays in the first angular section and the second angular section, when the X-ray generating section 106 is positioned at the center of the first angular section, And a first direction 1480 is shown as an example of a direction perpendicular to the illustrated direction 1470. [

For example, in the first information, if the weight and the time corresponding to the motion amount of the object are in a linear relationship as shown in Fig. 13C, the object will increase linearly in size.

14, it can be predicted that the size of the object at the third time point t12 is changed by the first change amount 1442 rather than the first size 1420, and accordingly, the third time point t12 ) Can be predicted to have a third size 1421. In this case,

It is also possible to predict that the size of the object at the fourth time point t13 is changed by the second variation amount 1444 from the first size 1420 and accordingly the size of the object at the fourth time point t13 is 4 size (1422). The size of the object at the fifth time point t14 can be predicted to change by the third amount of change 1446 from the first size 1420. Accordingly, 5 size (1423).

The size of the object at the third time point t12, the fourth time point t13 and the fifth time point t14 may be predicted by reducing the object having the second size 1430 based on the first information .

Specifically, the size, shape, and / or position of the target object at the target time point can be predicted using the first information. In the example of the motion of the object shown in Fig. 14, the image reconstructing unit 720 can estimate the magnitude of the magnitude of the magnitude of the object at the target point using the first information, and warp the object ) To generate a target image. Specifically, the warping of a target means motion compensation of the target object. The first information is used to predict the state (for example, at least one of the size, the shape, and the position) of the target object at the target point, Means restoring the target image by correcting the motion of the object.

15 is a diagram for explaining an operation of restoring a target image.

When the first information is obtained, the image restoring unit 720 restores the target image representing the target object at the target point based on the first information. Specifically, the image restoring unit 720 can predict the amount of motion of the object at the target point based on the first information, and restore the target image based on the predicted amount of motion.

Specifically, the image restoring unit 720 may restore the target image corresponding to the target point by using at least one of the plurality of partial angle images including the first image and the second image, and the first information.

Specifically, the image restoring unit 720 may restore a target image by warping a plurality of partial images representing a part of the object based on the first information.

Here, the partial angle image used for reconstructing the target image may be a reconstructed image using the projection data obtained in the partial angle section such as the first image and the second image. In addition, the image data may be generated by projecting a plurality of projection data corresponding to a plurality of consecutive adjacent views in a filtering manner, or may be an image generated by projecting projection data corresponding to one view in a filtering manner .

For example, the image restoring unit 720 can restore the target image at the target point of time (t = Ttarget) by warping the object based on the first information. More specifically, since the size of the object at the target point can be accurately predicted using the first information, the image reconstructing unit 720 predicts the reconstructed tomographic image using the projection data obtained during the one-week angular interval 1510 It is possible to restore the target image by warping according to the size of the target object.

The image reconstructing unit 720 reconstructs the first image obtained in the first angle interval 1530, the second image obtained in the second angle interval 1540, and the at least one partial image at a target time t = Ttarget The target image can be restored by warping according to the size of the object in the target image. Here, the object surfaces not displayed on at least one of the first image and the second image may include at least one of the angular intervals excluding the first angular interval 1530 and the second angular interval 1540 of the one-week angular interval 1510 And at least one partial angle image reconstructed corresponding to the projection data obtained in the angular interval may be acquired by warping.

Hereinafter, the operation of restoring the target image using the first information 1380 described in FIG. 13 will be described in detail.

In addition, in FIG. 15, the abdomen of the patient is shown as an example of an object, and a plurality of axial planes are restored as an example.

Specifically, the image reconstructing unit 720 reconstructs a target image using the plurality of projection data corresponding to a plurality of views, which are RO data acquired by the X-ray generator 106, can do. Specifically, the image reconstructing unit 720 may acquire a target image by motion-compensating an image obtained by projecting a plurality of projection data corresponding to a plurality of views in a filtering manner, based on the first information.

More specifically, in order to restore the target image at the target point of time Ttarget corresponding to the predetermined angle point 1520 in the one-week angular interval 1510, a weight value corresponding to the target point in the first information 1380 is used .

For example, referring to (c) of FIG. 13, a target weight value W1 corresponding to a target time point Ttarget is obtained from the first information. A plurality of filtered inverse projected images obtained by projecting each of the plurality of projection data corresponding to each of the plurality of views obtained in the one-week-period angular interval 1510 in a filtering manner are added to a weighted value corresponding to a weight value in each view And has a motion amount. Accordingly, in order to make each of the filtered-in-projected images have the motion state of the object at the target point, it is necessary to calculate the weighted value of the object corresponding to the difference between the weighted value of the target weight value W1 and the view Is applied to each filtered back projection image and warped. The target image can be reconstructed using a plurality of warped filtered projection images. Specifically, in the process of filtering back projection of the projection data acquired in the one-period angle section 1510, the target image can be restored by warping the pixels projected in the filtration direction using the first information have. The operation of recovering the target image by overwriting the pixels will be described in detail below with reference to FIG.

Alternatively, the image restoring unit 720 may back-project the plurality of projection data obtained in the one-period angular interval 1510 to obtain an image, and then, using the first information, Thereby performing target image restoration.

Specifically, the image reconstructing unit 720 reconstructs an initial image by projecting a plurality of projection data, which are RO data obtained by performing tomography and rotating in less than one rotation, in a filtering manner. The motion of the object at the target point can be estimated based on the first information, and the initial image can be rewritten based on the estimated motion to restore the target image.

In addition, the image reconstructing unit 720 warps an image grid composed of a plurality of pixels for imaging a target object based on the first information, and generates a target image using the warped image grid Can be restored. The target image can be reconstructed when back projection of the projection data obtained by tomography and rotation of the image grid using less than one rotation using the image grid corresponding to each viewpoint is performed. The restoration of the target image using image grid warping will be described in detail below with reference to FIG.

In addition, the image reconstructing unit 720 may reconstruct the target image by using the voxel to warp the center of the voxel representing the target based on the first information. Restoration of the target image using voxel overwriting will be described in detail with reference to FIG.

In addition, the target time point Ttarget can be set as a time point between the first time point t1 and the second time point t2. Specifically, the target time point Ttarget can be set to the middle point between the first time point t1 and the second time point t2. This will be described in detail with reference to FIGS. 16 to 18. FIG.

The restoration of the target image using the warping will be described in detail below with reference to FIGS. 20 to 24. FIG.

16 is a view for explaining target point setting.

Referring to FIG. 16, in the partial angle restoration (PAR), a clear part of the reconstructed image appears differently depending on the view angle at which the X-ray is irradiated. Specifically, there is a surface area that is more likely to be sampled depending on the viewing angle, and a surface area that is relatively less sampled.

Specifically, referring to FIG. 16A, when the X-ray is irradiated to the target object at the 5 o'clock direction 1620, the reconstructed image 1610 is shown using the RO data generated by the detected X-ray. The image 1610 clearly shows the surfaces 1631 and 1632 extending in the direction similar to the 5 o'clock direction 1620 and the surface extending in the direction perpendicular to the 11 o'clock direction 1620 is clear It does not appear.

Referring to FIG. 16B, when the X-ray is irradiated to the object at the 7 o'clock direction 1660, the reconstructed image 1650 is shown using the log data generated by the detected X-ray. The image 1650 clearly shows the surfaces 1671 and 1672 extending in the direction similar to the 7 o'clock direction 1660 and the surface extending in the direction perpendicular to the 7 o'clock direction 1660 is clear It does not appear.

That is, depending on the x-ray beam direction, the portion of the surface that is clearly imaged is different. Specifically, a surface portion extending in a direction similar to the x-ray beam direction can be more clearly imaged than other surface portions.

Therefore, if the target point of time Ttarget is set to the middle point between the first point of time t1 and the second point of time t2, the target image corresponding to the target point of time Ttarget can be more accurately restored . Specifically, when the target point of time Ttarget is set to the middle point between the first point of time t1 and the second point of time t2, the surface portion of the target object that is not clearly imaged by the projection data obtained at the target point of time Ttarget By imaging the surface portion of the object clearly imaged by the projection data obtained at at least one of the first time point t1 and the second time point t2 and imaging the object at the target point more clearly Imaging is possible.

Fig. 17 is another diagram for explaining target point setting. Fig.

Referring to Fig. 17, Fig. 17 corresponds to Fig. 17 as a whole. Specifically, the target object 1705, the first angle section 1711, and the second angle section 1712 in Fig. 17 correspond to the object 1405, the first angle section 1411, and the second angle section 1412 ). In the object 1720 in the first image obtained in the first angle section 1711, the surfaces 1721 and 1722 are clearly imaged as shown. Also, in the object 1760 in the second image obtained in the second angle section 1712, the surfaces 1761 and 1762 are clearly imaged as shown.

On the other hand, in the object 1740 in the image obtained in the angle section corresponding to the target time point Ttarget, the surfaces 1741 and 1742 are clearly imaged as shown.

That is, the surfaces (1741, 1742) clearly imaged in the object 1740 corresponding to the target time point Ttarget and the surfaces (1741, 1742) that are clearly imaged in the objects 1720, 1760 corresponding to the first and second images 1721 and 1722, or 1761 and 1762 are portions that do not overlap with each other. The target point of time may be set as an intermediate point between the first point of time t1 and the second point of time t2 and the target image representing the state of the object at the set point of interest may be restored.

Specifically, in imaging the object, surface portions (e.g., 1722 and 1721, or 1761 and 1762) that extend in a direction similar to the 1791 direction may image and image at least one of the first image and the second image, Surface portions (for example, 1741 and 1742) extending in a direction similar to the 1741 direction can be imaged by image-waving the obtained image in the angular interval corresponding to the target time point Ttarget. Therefore, even the surfaces that are not clearly sampled at the target point can be clearly imaged in the restored target image.

In the example of FIG. 17, the target image is restored by warping the partial angle image projected in the filtering region. However, the image restoring unit 720 may restore the target image by adjusting the projection data itself. Specifically, it is possible to correct each of the projection data acquired in the one-period angular interval in accordance with the state of the object at the target point. Specifically, the plurality of projection data included in the one-period angular section images different parts of the object according to the view. Accordingly, the image restoring unit 720 predicts the state of the target object at the target point by using the first information, adjusts each of the plurality of projection data corresponding to the plurality of views according to the state of the predicted object, And the target image may be restored by projecting a plurality of projection data.

18A is a diagram for explaining restoration of a target image indicating a moving object. Specifically, FIG. 18A is a diagram for explaining that the X-ray generator 106 rotates about the object 1801 and performs tomography. 18A is a diagram for explaining an operation of backprojecting projection data obtained by filtering RO data obtained through tomography.

In FIG. 18A, the X-ray generator 106 rotates about the object 1801 to perform tomographic imaging, and a tomographic image is reconstructed using Filtered Back Projection. In addition, a case in which the object 1801 includes one circular object 1802 as shown is shown as an example. In addition, as described with reference to FIG. 13, the one-week angular interval 1360 is 180+ fan angle, which is a section of the projection data, but FIG. 18A shows an example of performing tomography for 180-degree rotation for convenience of explanation.

18A, the X-ray generator 106 moves along a circular source trajectory 1810 and irradiates x-rays to a target object at each of a plurality of points having a predetermined angular interval to generate projection data ( projection data. Then, the filtered projection data obtained by filtering the projection data is obtained. 18A, a plurality of points located on the source locus 1810 represent points where the X-ray generation unit 106 is located and emits x-rays. For example, the X-ray generator 106 may move the X-ray generator 106 at predetermined intervals such as 0.5-degree intervals, 1-degree intervals, 3-degree intervals, And starts to rotate at the first time point T1 and rotates to the second time point T2. Accordingly, the first time point T1 corresponds to the rotation angle 0 degree, and the second time point T2 corresponds to the rotation angle 180 degrees.

Specifically, when the X-ray generating unit 106 irradiates the object 1801 with the X-ray at the first time point T1, the X-ray emitted in the direction 1832 passes through the object 1813, . The obtained signal 1831 may have a different signal value on the surface of the object due to the difference in transmittance of the x-ray depending on the material. Specifically, the signal values may be varied on a surface arranged in a direction parallel to the X-ray irradiating direction 1832.

When the X-ray generator 106 irradiates X-rays to the object 1801 at the third time point T12, the X-rays emitted in the direction 1834 pass through the object 1814 to acquire the signal 1833 do. The acquired signal 1833 may have a different signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1834.

When the X-ray generator 106 irradiates X-rays to the object 1801 at the fourth time point T13, the X-rays emitted in the direction 1836 pass through the object 1815 to acquire the signal 1835 do. The obtained signal 1835 may have a different signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1836.

When the X-ray generator 106 irradiates the X-ray to the object 1801 at the fifth time point T14, the X-ray emitted in the direction 1838 passes through the object 1816 and acquires the signal 1837 do. The obtained signal 1837 may have a signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1838.

When the X-ray generator 106 irradiates the object 1801 with the X-ray at the second time point T2, the X-ray emitted in the direction 1824 passes through the object 1817 and acquires the signal 1839 do. The obtained signal 1839 may have a different signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1824.

The signal 1831 also includes information about the surfaces arranged in the direction 1832 so that the image 1851 obtained by projecting the signal 1831 back through the filter images the surface arranged in the direction 1832 Contributing. Also, the signal 1833 includes information about the surface arranged in the direction 1834 such that the filtered projection data corresponding to the signal 1833 contributes to imaging the surface arranged in the direction 1834. That is, the projection data acquired in each view contribute to imaging the surface of the object corresponding to each view. This can be explained by a Fourier slice theorem showing the relationship between the value of the projection data obtained by projecting the object 1801 to the parallel beam and the frequency component of the image. Here, 'view' corresponds to the direction, position and / or angle of rotation of the X-ray generator 106 to irradiate the object with the X-rays.

In addition, it is possible to obtain a signal (for example, 1831) in the DAS 116 described in FIG. 4, and to generate the filtered projection data by processing the signal 1831 acquired by the image processing unit 126 have. Then, the filtered projection data is reversely projected to acquire the image 1851.

Specifically, when the X-ray generator 106 rotates to acquire a plurality of filtered projection data by emitting X-rays from a plurality of points (or a plurality of views), a plurality of filtered projection data (Backprojection) to reconstruct the tomographic image. That is, an image representing a target object can be acquired through a backprojection process in which filtered projection data is distributed to image pixels.

Referring to FIG. 18A, the surface of the object 1802 included in the object 1801 at the first time point T 1 appears in the backprojected image 1851 corresponding to the first time T 1. Then, the filtered projection data for each of the plurality of views obtained while rotating in the counterclockwise direction is accumulated and backprojected.

For example, the filtered projection data acquired in the 22.5 degree angular interval is accumulated and backprojected to obtain the reverse projection image 1853. [ In the reverse projection image 1853, a part of the surface 1854 of the object 1802 in the object 1801 appears.

Subsequently, the filtered projection data obtained in the 45-degree angular interval is accumulated and backprojected to acquire the back projection image 1855. [ In the reverse projection image 1855, a part of the surface 1856 of the object 1802 in the object 1801 appears.

 Subsequently, the filtered projection data obtained in the 98 degree angular interval is accumulated and backprojected to obtain the back projection image 1857. [ In the reverse projection image 1857, a partial surface 1858 of the object 1802 in the object 1801 appears.

Subsequently, the filtered projection data obtained in the 180-degree angular interval is accumulated and backprojected to acquire the back projection image 1859. [ In the reverse projection image 1859, the surface of the object 1802 in the object 1801 appears entirely.

In the case of the moving object, the first point of time T1, the third point of time T12, the fourth point of time T13, the fifth point of time T14, and the second point of time At least one of the states, e.g., size, position, and shape, of the object in each of the first and second regions T2 is the same.

Accordingly, in reconstructing a tomographic image by accumulating data of filtering and reversing projection of a plurality of projection data corresponding to a plurality of views included in one angular interval, the states of the objects in each of the plurality of views are the same, Blurring due to motion artifacts does not occur in the image 1859 that has been generated.

FIG. 18B is a diagram for explaining motion artifacts that may occur in restoring a target image representing a moving object. FIG. Specifically, FIG. 18B (a) is a view for explaining that the X-ray generator 106 rotates about the object 1805 and performs tomography. 18B is a diagram for explaining an operation of backprojecting the projection data obtained by filtering the RO data obtained through tomography. In (b) of FIG. 18B, a case of reconstructing a tomographic image using Filtered Back Projection will be described as an example. In addition, a case is shown in which the object 1805 includes two circular objects 1806 and 1807 as shown in the figure. Hereinafter, for convenience of explanation, the upper circular object 1806 is referred to as a 'first object 1806' and the lower circular object 1807 is referred to as a 'second object 1807'. In addition, as shown in FIG. 13, the one-week angular interval 1360 is 180+ fan angles, but FIG. 18B shows an example of performing tomography for 180 degrees rotation for convenience of explanation.

18B, the X-ray generator 106 moves along a circular source trajectory 1810 and irradiates x-rays to a target object at each of a plurality of points having a predetermined angular interval to generate projection data ( projection data. Then, the filtered projection data obtained by filtering the projection data is obtained. In FIG. 18B (a), a plurality of points located on the source locus 1810 indicate points where the X-ray generation unit 106 is located and emits the X-rays. For example, the X-ray generator 106 may move the X-ray generator 106 at predetermined intervals such as 0.5-degree intervals, 1-degree intervals, 3-degree intervals, And starts to rotate at the first time point T1 and rotates to the second time point T2. Accordingly, the first time point T1 corresponds to the rotation angle 0 degree, and the second time point T2 corresponds to the rotation angle 180 degrees.

A target object 1820, a target object 1821, a target object 1820, and a target object 1820 at a first time point T1, a third time point T12, a fourth time point T13, a fifth time point T14, (1822), object (1823), and object (1830). Specifically, the first object 1806 included in the object 1085 expands in size at the corresponding position, and the second object 1807 does not expand in size but can move from the left to the right.

Specifically, when the X-ray generating unit 106 irradiates the object 1805 with the X-ray at the first time point T1, the X-ray emitted in the direction 1845 passes through the object 1820 to transmit the signal 1840 . The acquired signal 1840 may have a different signal value on the surface of the object due to the difference in transmittance of the x-ray depending on the material. Specifically, the signal values may be different on a surface arranged in a direction parallel to the X-ray irradiating direction 1845.

When the X-ray generator 106 irradiates the object 1805 with the X-ray at the third time point T12, the X-ray emitted in the direction 1846 passes through the object 1821 and acquires the signal 1841 do. The obtained signal 1841 may have a signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1846.

When the X-ray generator 106 irradiates the X-ray to the object 1805 at the fourth time point T13, the X-ray emitted in the direction 1847 passes through the object 1822 and acquires the signal 1842 do. The acquired signal 1842 may have a different signal value at a surface arranged in a direction parallel to the x-ray emitting direction 1847. [

When the X-ray generating unit 106 irradiates the object 1805 with the X-ray at the fifth time point T14, the X-ray emitted in the direction 1849 passes through the object 1823 and acquires the signal 1843 do. The obtained signal 1843 may have a signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1849. [

When the X-ray generator 106 irradiates the X-ray to the object 1805 at the second time point T2, the X-ray emitted in the direction 1850 passes through the object 1830 and acquires the signal 1844 do. The obtained signal 1844 may have a different signal value at a surface arranged in a direction parallel to the X-ray irradiating direction 1850.

Also, the signal 1840 includes information about the surfaces arranged in the direction 1845 such that the image 1861 generated by projecting the signal 1840 back-filtered imaged a surface arranged in the direction 1845 Contributing. The signal 1841 also includes information about the surfaces arranged in the direction 1846 so that the filtered projection data corresponding to the signal 1841 contributes to imaging the surface arranged in the direction 1946. That is, the projection data acquired in each view contribute to imaging the surface of the object corresponding to each view. Here, 'view' corresponds to the direction, position and / or angle of rotation of the X-ray generator 106 to irradiate the object with the X-rays.

It is also possible to obtain a signal (e.g., 1840) in the DAS 116 described in FIG. 4 and to generate the filtered projection data by processing the signal 1840 obtained at the image processing unit 126 have. Then, the filtered projection data is reversely projected to acquire the image 1861.

Specifically, when the X-ray generator 106 rotates to acquire a plurality of filtered projection data by emitting X-rays from a plurality of points (or a plurality of views), a plurality of filtered projection data (Backprojection) to reconstruct the tomographic image. That is, an image representing a target object can be acquired through a backprojection process in which filtered projection data is distributed to image pixels.

18B, the backprojected image 1861 corresponding to the first point in time T 1 includes the surface 1811 of the first object 1811 included in the object 1820 at the first point in time T 1 1862 and the surface 1863 of the second object 1812 appear. Then, the filtered projection data for each of the plurality of views obtained while rotating in the counterclockwise direction is accumulated and backprojected.

For example, the filtered projection data acquired in the 22.5 degree angular interval is accumulated and backprojected to obtain the back projection image 1865. [ The reverse projection image 1865 shows a partial surface 1866 of the first object 1806 and a partial surface 1876 of the second object 1807 in the object 1805.

Subsequently, the filtered projection data obtained in the 45-degree angular interval is accumulated and backprojected to acquire the reverse projection image 1870. [ A part of the surface 1871 of the first object 1806 and a part of the surface 1872 of the second object 1807 appear in the object 1805 in the reverse projection image 1870. [

 Subsequently, the filtered projection data obtained in the 150-degree angular interval is accumulated and backprojected to acquire the back projection image 1875. [ In the reverse projection image 1875, a partial surface 1876 of the first object 1806 and a partial surface 1877 of the second object 1807 appear in the object 1805.

Subsequently, the filtered projection data obtained in the 180-degree angular interval is accumulated and back-projected to acquire the reverse-projected image 1880. In the reverse projection image 1875, the surfaces of the first object 1806 and the second object 1807 in the object 1805 are entirely displayed.

In FIG. 18B (b), the image 1890 is a tomographic image showing the object finally reconstructed through a reverse projection process.

However, due to the motion of the object, the surface information between the filtered projection data obtained in each view becomes inconsistent. Accordingly, when a plurality of filtered projection data obtained in one-period angular intervals are accumulated, blurring (1881, 1882) appears without the surface being clearly displayed as shown in the figure.

Herein, the motion of a target object can be estimated even when the target object includes various materials, surfaces, and / or shapes as in the target object 1805 shown in FIG. 18B. The motion of the object can be accurately estimated, and the motion-compensated image can be restored. The above-described image restoration operation using the first information will be described in detail below with reference to FIG. 19 to FIG.

18C is a diagram for explaining a target object represented by a three-dimensional tomographic image. Although the two-dimensional tomographic image has been described in the above-described drawings, the target image may be reconstructed into a three-dimensional tomographic image.

Specifically, referring to FIG. 18C, the object can be reconstructed into a three-dimensional tomographic image 1895 as shown in FIG. In the case of restoring the target image into the three-dimensional tomographic image 1895, the first image and the second image are also obtained as a three-dimensional tomographic image representing the object, and the first information includes motion information of the object on the three- .

For example, when a target object is represented by a first object 1896 and a second object 1897 as shown in (a) of FIG. 18B, the first information may include a first object 1896 and a second object 1896 1897). ≪ / RTI > 19 is a diagram for explaining the measurement of the amount of motion of the object. In Fig. 19, the first angular section 1901 and the second angular section 1902 correspond to the first angular section 1361 and the second angular section 1362 described in Fig. 13, respectively. The first image 1910 and the second image 1920 correspond to the first image 1310 and the second image 1320 described in FIG. 13, respectively. The motion vector field (MVF) information 1940 is the same as the motion vector field information described in FIG. 13B. Therefore, in FIG. 19, a description overlapping with FIG. 18 is omitted. Note that the object 1805 in Fig. 19 is the same as the object 1805 described in Fig. 18B, so that the description overlapping with Fig. 18B is omitted.

Referring to FIG. 19, the X-ray generator 106 obtains a first image 1910 using projection data corresponding to the first angle section 1901 obtained by rotating around a target object 1805 . The surfaces 1911 and 1912 included in the first object 1806 and the surfaces 1913 and 1914 included in the second object 1807 are displayed in the first image 1910. In addition, the X-ray generator 106 rotates about the object 1805 to obtain the second image 1920 using the acquired projection data corresponding to the acquired second angle section 1902. The surfaces 1921 and 1922 included in the second object 1807 and the surfaces 1923 and 1924 included in the second object 1807 are displayed in the second image 1920. That is, the projection data obtained in each view or the predetermined angle section included in one-degree angular interval contributes to imaging different surfaces or different areas of the object.

The data acquiring unit 710 acquires the first image 1910 and the second image 1920 from the image 1930 and the second image 1920 because the surface of the same part of the object is displayed in the first image 1910 and the second image 1920. [ ) To obtain a motion vector field (MVF) 1940 indicating the motion of the object. The motion vector field 1940 includes a vector 1941 indicating the moving direction and the magnitude of the movement of the same site so that the motion vector field 1940 can be transformed from the first point of time T1 to the second point of time T2 The first information indicating the movement of the object between the first and second objects can be obtained.

Here, since the first image 1910 and the second image 1920 are reconstructed using the projection data obtained in the partial angle section, the time resolution is high and the motion artifact can be minimized. The target image restoration at the target point using the obtained motion vector field 1940 will be described in detail below with reference to FIGS. 20 and 21. FIG.

20A is another drawing for explaining an operation of restoring a target image. In Fig. 20A, a description overlapping with Figs. 18B and 19 is omitted.

The image restoring unit 720 restores the target image at the target point of time Ttarget using information indicating the motion of the object, for example, a motion vector field.

As described above, the first information 2080 may be obtained using the motion vector field 1940. The first information is the same as the first information described in (c) of FIG. 13, and a detailed description thereof will be omitted. The first information 2080 can be used to predict the degree of motion of the object at the target time point Ttarget. The first information 2080 may be used to predict a state including at least one of the size, shape, and position of the target object at the target time point Ttarget.

As described above with reference to Fig. 19, the projection data obtained in each view or in the predetermined angle section included in one angular interval contributes to imaging different surfaces or different areas of the object.

The image reconstructing unit 720 reconstructs the target image by using the projection data obtained at the target point of time Ttarget except for the surface portion of the object or the region of the object, The surface region of the object or the region of the object imaged by the projection data can perform motion correction using the first information.

In FIG. 20A, for convenience of explanation, images are shown in which one-period angular intervals are divided into five angular intervals (2001, 2002, 2003, 2004, 2005) and the projection data acquired in each of the divided angular intervals is reversed. Specifically, the partial image 2021 is acquired by projecting the projection data obtained in the first angle section 2001 backward. Then, the projection data obtained in the third angle section 2002 is backprojected to obtain the partial image 2031. [ Then, the partial image 2041 is acquired by projecting the projection data obtained in the fourth angular interval 2003 backward. Then, the projection data obtained in the fifth angular interval 2004 is reversely projected to acquire the partial image 2051. Further, the partial image 2061 is obtained by projecting the projection data obtained in the second angle section 2005 backward.

20A, the first angular section 2001, the second angular section 2005, the partial image 2021, and the partial image 2061 correspond to the first angular section 1901, the second angular section 1902, and the first image 1910 and the second image 1920, respectively.

Referring to FIG. 20A, a case where the target time point Ttarget is set as an intermediate point between the first time point T1 and the second time point T2 is exemplified. As described with reference to FIG. 17, only the surfaces 2042, 2043, 2044, and 2045 arranged in the left and right direction as in the case of the partial image 2041 can be obtained by projecting the projection data obtained in the angle section adjacent to the target time point Ttarget Lt; / RTI > Surfaces that are not imaged in the partial image 2041 are imaged using projection data obtained in the angular intervals except for the fourth angular interval 2003 which is an angular interval including the target point in one angular interval.

The image restoring unit 720 may perform motion correction so that blurring is minimized using the first information when imaging the unimaged surfaces in the partial image 2041. [

Specifically, the surfaces or partial regions appearing in the partial image 2021 obtained in the first angle section 2001 are corrected according to the motion vector field. That is, referring to the first information 2080, it is assumed that the amount of motion W in the first angular section 2001 is 0 and the amount of motion of the object at the target time point Ttarget 2081 is W1 = 0.5. Then, the object included in the partial image 2021 corresponding to the first angle section 2001 is warped by the amount of motion W = 0.5 to accurately acquire the surface of the object at the target point Ttarget 2081 . Therefore, the partial image 2021 is motion-corrected based on the motion amount 2024 generated from the starting point (t = 0) to the target point-in-time (Ttarget) against the total motion amount 2023 And generates a partial image 2022. Here, the total motion amount 2024 corresponds to the motion amount W = 1 in the first information 2080, and the motion amount 2024 corresponds to the motion amount 2024 at the time t = 0 corresponding to the first angle section 2001 Of the motion amount W at the target point in time Ttarget.

The motion compensation is performed in the same manner as in the first angular interval even in the remaining angular intervals. Specifically, on the basis of the amount of motion 2034 generated from the third time point T12 to the target time point Ttarget with respect to the total motion amount 2023, the projection data obtained in the third angle section 2002 is decentered The partial image 2031 is motion-corrected to generate a corrected partial image 2022. [

In addition, based on the amount of motion 2064 generated from the end point (t = end) to the target point of time (Ttarget) against the total motion amount 2023, the projection data obtained in the second angular section 2005 is deflected The partial image 2061 is subjected to motion correction to generate a corrected partial image 2062. In addition, based on the amount of motion 2054 generated from the fifth time point T14 to the target time point Ttarget in contrast to the total motion amount 2023, a portion reverse to the projection data obtained in the fifth angular interval 2004 And performs motion correction on the image 2051 to generate a corrected partial image 2052. [

Here, the motion compensation using the projection data obtained at the time before the target point-in-time Ttarget and the motion compensation using the projection data obtained at the point-in-time after the target point-in-time Ttarget are performed in the opposite directions . Specifically, referring to the first information 2080, motion compensation is performed in a direction 2085 in which the motion amount W increases at a point before the target point of time Ttarget, and motion compensation is performed at a point of time after the target point of time Ttarget The motion compensation is performed in a direction 2086 in which the number of pixels W decreases. Therefore, the direction of the total motion amount 2023 at the first time point T1 and the total motion amount 2023 at the second time point T2 are shown in the opposite direction.

In addition, the first information includes motion information of a surface imaged on the partial image 2021 and the partial image 2061. [ Accordingly, the image reconstructing unit 720 can perform a motion by warping a surface or a partial area of the object in a first direction (a direction perpendicular to the irradiation direction of the x-ray in the first angular interval 2001 and the second angular interval 2005) Correction can be performed.

The partial image 2041 obtained in the fourth angle section 2003 including the corrected partial images 2022, 2032, 2052 and 2062 and the target point of time Ttarget is used to correspond to the target point of time Ttarget The target image can be restored. Here, since the corrected partial images 2022, 2032, 2052, and 2062 accurately reflect the motion state of the object at the target time point Ttarget, the motion-compensated and restored target image using the first information Motion artifacts can be generated with minimized.

In the case of reconstructing an image by performing tomographic imaging of a moving object without performing motion compensation, blurring may occur severely on a surface portion due to projection data obtained at a point far from the target point of view. Specifically, in the partial image 2041 obtained in the fourth angular interval 2003 including the target point of time Ttarget, the surfaces extending in the left and right direction are imaged, and in the partial image 2041, Are imaged in the partial image 2021 and the partial image 2061 corresponding to the first view point T1 and the second view point T2 which are farthest from the target viewpoint. As described above, the partial image 2021 obtained in the first angle section 2001, which is the start angle section and the partial image 2061 obtained in the second angle section 2005, which is the end angle section due to the motion of the object, The surfaces imaged in the first embodiment are significantly different in position and size from each other. That is, the projection data obtained in the start angle interval and the projection data obtained in the end angle interval are most severely blurred in the final reconstructed image. Therefore, the vertically extending surfaces in the target image are blurred due to surfaces having a position and size difference imaged in the partial image 2021 and the partial image 2061. [ Specifically, when the middle point between the first point of time T1 and the second point of time T2 is set as the target point of time Ttarget as shown in FIG. 18 (a), as shown in FIG. 18 (b) The blurring 1881 and 1882 are most severely generated in the vertically extending surfaces.

In the embodiment of the present invention, the motion reconstruction unit 720 performs the motion compensation of the partial images obtained in the one-period angular interval using the first information to generate the target image 2070, thereby reducing the motion artifact .

In addition, if the target point of time Ttarget is set between the first point of time T1 and the second point of time T2, which are the start and end points of the one-week angular interval, blurring in the reconstructed image corresponding to the target point It is possible to effectively perform motion compensation for the severely occurring surfaces 1881 and 1882, thereby minimizing motion artifacts in the reconstructed image. Therefore, if the target point of time Ttarget is set as an intermediate point of the one-week angular interval and motion compensation is performed using the first information, the target image having the optimized image quality can be restored.

Specifically, the first information is obtained using the partial image 2021 and the partial image 2061 generated using the projection data obtained in the first angular interval 2001 and the second angular interval 2005, The first information may include motion information for surface components (e.g., '2025, 2026, 2027, and 2028' or '2065, 2066, 2067, and 2068') included in the partial image 2021 and the partial image 2061 The most accurate. Therefore, if motion compensation is performed based on the first information, the surface components ('2025, 2026, 2027, and 2028' or '2065, 2066, 2067, and 2068') arranged in the up- . However, in the first information, a partial image generated based on projection data acquired in a view included in a section other than the first angular section 2001 and the second angular section 2005 (for example, 2031, 2041, or 2051 is less accurate than the motion information on the surface components included in the partial image 2021 and the partial image 2061 described above.

Specifically, the movement of the surface found in the first and second angular sections 2001 and 2005, which are the start and end sections of the one-week angular section, is referred to as a first angular section 2001 and a second angular section 2005, The degree of correlation with the movement of the surface found in an orthogonal angle section (for example, 2003) of the surface is lowest. Therefore, in the projection data obtained in the angular section (for example, 2003) orthogonal to the first angular section 2001 and the second angular section 2005 among the motion information on the object surface by the first information, An error may be the largest in the motion information on the surface component included in the image (for example, 2041) generated by the motion information.

In setting the target time point, a first angle section 2001, which is an intermediate point between the first angle section 2001 and the second angle section 2005, and a time point T13, which is orthogonal to the second angle section 2005, The surface component imaged by the projection data obtained in the fourth angular interval 2003 which is an angular section orthogonal to the first angular interval 2001 and the second angular interval 2005 (for example, 2042 , 2043, 2044, and 2045 need not perform motion compensation. (2042, 2043, 2044, and 2045, for example) in an angular section orthogonal to the first angular section 2001 and the second angular section 2005, ), It is possible to minimize the influence of the error that may occur in the motion compensation of the object. Therefore, if the position of the target point of time Ttarget is positioned at an intermediate point between the first angle section 2001 and the second angle section 2005, the image quality of the restored target image can be maximized.

In addition, although FIG. 20A illustrates an example in which one-week angular interval is divided into a plurality of angular intervals and motion compensation is performed for each of the back-projected images corresponding to the angular intervals, the angle included in the angular interval The motion compensation may be performed in a process of performing motion compensation on a partial image inversely projecting the projection data obtained in a view or in the process of reversely projecting projection data acquired in each of the views. In addition, motion compensation may be performed in the process of performing motion compensation on a partial image inversely projecting the projection data obtained in one view group including several views, or in the reverse projection of the projection data obtained in the view group There will be.

20A, motion compensation is performed on partial images. However, motion compensation may be performed on each projection data corresponding to each view, and the corrected projection data may be projected in a reverse direction on the filter, You can also restore it.

20B is a view showing the restored target image. 20B, the object includes an object 2071 and an object 2072, and the object 2071 and the object 2072 respectively include a first object 1806 included in the object 1805 shown in FIG. 20A, And the second object 1807, respectively.

20B, the target image 2070 restored by the image restoring unit 720 according to the embodiment of the present invention is a target image 2070 obtained by dividing the target point of time Ttarget by a distance between the first point of time T1 and the second point of time T2 , It indicates a target object.

The target image 2070 has almost no blurring due to motion artifacts and accurately reflects the state of the object at the target point.

21A is another drawing for explaining an operation of restoring a target image.

Referring to FIG. 21A, the target point of time Ttarget is substantially the same as that of FIG. 20A except that the target point of time Ttarget is set as a point of time that is not the middle point of the one-week angular interval.

Referring to FIG. 21A, the target time point Ttarget may be set to a time point (for example, a third time point T12) that is not the middle point of the one-week angular interval.

21A, a partial image 2121 is subjected to a motion correction 2121 based on a motion amount 2124 generated from a starting point (t = 0) to a target point of time Ttarget in contrast to the total motion amount 2123 ) To generate a corrected partial image 2122. [ Here, the total motion amount 2123 corresponds to the motion amount W = 1 in the first information 2180 and the motion amount 2124 corresponds to the motion amount W at the start time t = Corresponds to the difference value 'of the amount of motion W2 at the time point (Ttarget) 2181'.

The motion compensation is performed in the same manner as in the first angular interval even in the remaining angular intervals. Specifically, based on the motion amount 2144 generated from the fourth time point T13 to the target time point Ttarget in comparison with the total motion amount 2123, motion correction is performed on the partial image 2141, And generates a partial image 2142.

The partial image 2151 is motion-corrected based on the motion amount 2154 generated from the fifth time point T14 to the target time point Ttarget in comparison with the total motion amount 2123, And generates an image 2152. The partial image 2161 is subjected to motion correction based on the motion amount 2164 generated from the end point t = end to the target point of time Ttarget in contrast to the total motion amount 2123, And generates a partial image 2162.

A target image corresponding to the target point of time Ttarget is obtained by using the partial image 2131 obtained in the angle section 2002 including the corrected partial images 2122, 2142, 2152, and 2162 and the target point of time Ttarget. The image can be restored.

21B is another diagram showing the restored target image.

Referring to FIG. 21B, the target image 2170 restored by the image restoring unit 720 according to the embodiment of the present invention includes a first point of time Ttarget and a second point of time Ttarget, T2), it indicates a target object.

The target image 2170 has little blurring due to motion artifacts.

However, if the target point of time Ttarget is not the middle point between the first point of time T1 and the second point of time T2, the image quality of the reconstructed image 2170 is the target point of time Ttarget, The image quality of the reconstructed image 2070 may be lower than that of the reconstructed image 2070 at the intermediate point of time T2. For example, when the image 2170 and the image 2070 are compared, it can be seen that the shapes of the first object 2171 and the second object 2172 included in the object are partially deformed. Specifically, in the image 2170, the shape of the lower surface of the first object 2171 may be slightly distorted.

That is, in the target image, the degree of motion correction of the target object included in the target image may vary according to the target time. Specifically, the closer the target point is to the middle point between the first point of time T1 and the second point of view T2, the better the motion correction becomes, and the target image becomes a video that better reflects the state of the target point at the target point . In contrast, when the target point of time is not the middle point between the first point of time T1 and the second point of time T2, the motion compensation is less so that the state of the target object at the target point is set to the first point of time T1) and the second time point (T2).

Therefore, when the target point of view corresponds to the intermediate angle between the first angle section and the second angle section in the restored target image, motion compensation of the target object can be performed better than when the target point does not correspond to the intermediate angle .

Describing it from the viewpoint of image quality, the image quality of the reconstructed image may vary depending on which point or point in the one-week angular interval is set as the target point. Here, the 'image quality' may vary depending on how well the image represents the state of the object at a specific point in time, for example, it may correspond to the degree of shape deformation of the object. For example, an image that accurately reflects the state of an object at a specific time point can be said to have good image and image quality. On the other hand, if the state of the object at a specific time point can not be accurately reflected and at least one of the position, the shape, and the size is different from the state of the object at the specific time point, the image quality is bad. Specifically, as shown in FIGS. 20B and 21B, when the target time point is the middle point between the first time point T1 and the second time point T2, the image quality of the restored image is optimized most.

22 is a diagram for explaining a warping operation used for restoring a target image.

In order to restore the target image, the image restoring unit 720 restores the filtered projection data obtained from the plurality of views included in the one-week angular interval to the back-projection image 2201, ). Hereinafter, the back projection of the partial region 2202 included in the image domain 2201 will be described. Here, 'region 2202' may be image data including pixel values as shown, or may be an image itself imaged by pixel values. Also, 'area 2202' may be the image space itself for imaging the object. In FIG. 22, the case where the filtered projection data 2210 is backprojected by irradiating the X-ray in the direction 2211 at a first point in time T1, which is the start point of the one-week angular interval, will be described as an example. Here, the image data included in the area 2202 may be referred to as 'projected projection data'.

22, the image reconstructing unit 720 reconstructs an image grid composed of a plurality of pixels for imaging a target object based on the first information to a motion amount of a target object at a target point of time Ttarget Therefore, it is possible to warp and restore the target image using the warped image grid.

22, the filtered projection data 2210 sprays the filtered projection data 2210 onto an image grid included in the area 2202. [ Here, sputtering of the filtered projection data 2210 onto an image grid, which is an image space, is called 'back-projection'.

Accordingly, the area 2202 is filled with the pixel values 2213 as shown. If motion has not occurred in the object, even if the image is accumulated while the filtered projection data 2210 according to each view is accumulated and accumulated on the image grid, motion artifacts may not be generated in the reconstructed target image. However, if motion occurs in the object during one-week angular interval, there is a difference between the surfaces representing the same part of the object in the plurality of filtered projection data acquired in each view. Accordingly, when the image is imaged while the filtered projection data 2210 according to each view is accumulated and distributed to the image grid, motion artifacts are generated in the reconstructed target image.

In the present embodiment, motion compensation is performed as described in Figs. 20A and 21A in order to minimize motion artifacts of a moving object. Hereinafter, a description will be made in detail of the image grid warping of the image reconstruction unit 720 for motion compensation.

The image reconstructing unit 720 transforms an image grid 2230 for imaging the same region as the region 2202 using first information indicating the motion of the object, for example, MVF information. And warps according to the motion vector field indicating the amount of motion of the object to the target point in the motion vector field 2202. For example, the left upper region in the image grid 2230 may be warped along a vector 1941.

Accordingly, a watermarked image grid 2240 is generated from the image grid 2230. The image reconstruction unit 720 scatters the pixel values included in the projection data 2210 filtered on the warped image grid 2240. Accordingly, the pixel values are included as shown in the area 2235 corresponding to the area 2202 in the same manner. In region 2235, a rectangular image grid 2241, shown in phantom, represents a generic image grid without warping applied.

Subsequently, the image reconstructing unit 720 resamples the area 2235 including the pixel values along the warped image grid 2240 into the area 2245 including the pixel values along the square image grid 2241 resampling. Specifically, the pixel values along the warped image grid 2240 are interpolated using a quadratic image pixel matrix to convert them to pixel values according to Cartesian coordinates.

Hereinafter, the case where the pixel values 2242 and 2243 included in the warped image grid 2240 are resampled to the pixel values 2254 included in the rectangular image grid 2241 will be described as an example. The pixel 2242 included in the warped image grid 2240 has a signal value of '2' and the pixel 2243 has a signal value of '1'. That is, since the video signal value included in the entire pixel 2242 is 2, the signal value '2' is dispersed and included in the area ratio of the pixel 2242. Accordingly, the signal value '1' may be included in the partial area 2261 corresponding to half of the entire area of the pixel 2242. Also, since the video signal value included in the entire pixel 2243 is 1, the signal value '1' is dispersed and included in the area ratio of the pixel 2243. Accordingly, the signal value '0.5' may be included in the partial area 2262 corresponding to half of the entire area of the pixel 2242. The pixel 2254 along with the rectangular image grating 2241 and 2251 including the partial area 2261 and the partial area 2262 is further provided with a signal value '1' of the partial area 2261 and a signal value ' And '1.5' which is a signal value obtained by adding the value '0.5'.

Accordingly, the resampled region 2245 is arranged with the pixel values according to the rectangular image grid 2251. Accordingly, it is possible to generate pixel values 2255 included in the area 2245 by resampling all the pixel values included in the area 2235. [

In addition, a method of converting pixel values arranged according to a warped image grid into pixel values arranged according to a rectangular image grid may be applied to various methods other than the above-described example.

In addition, motion compensation can be performed by performing motion compensation using warping for all of the backprojected projection data corresponding to a plurality of views included in one angular interval. The target image can be restored by accumulating a plurality of motion-compensated projected projection data.

In addition, motion compensation through warping of an image grid is not performed for each view, but may be performed for each of a plurality of views included in one group by grouping a plurality of views at predetermined angular intervals.

As in the above-described example, the image restoring unit 720 may generate the motion-compensated image data 2270 using the warped image grid based on the first information.

23 is another diagram for explaining a warping operation used for restoring a target image. In FIG. 23, a description overlapping with FIG. 22 is omitted.

Specifically, the image reconstructing unit 720 may generate a motion-compensated target image by warping the back-projected image according to the first information. Specifically, the image restoring unit 720 may restore a target image by warping pixels corresponding to data obtained by tomography, based on the first information, in a back projection process. Specifically, the image reconstructing unit 720 may warp a pixel according to a motion amount of a target object at a target point of time Ttarget according to a motion vector field (MVF).

Referring to FIG. 23, pixels of an image (or image data) 2330 generated by reversely projecting the filtered projection data 2210 are warped based on a motion vector field 1941. Accordingly, the pixel values 2331 contained in the image 2330 are generated as a warped image 2335 so as to correspond to the motion of the object at the target time point Ttarget based on the motion vector field. Specifically, the filtered projection data 2311 is corresponded as in pixel values 2336 in the watermarked image 2335 and the filtered projection data 2312 is associated with pixel values 2335 in the watermarked image 2335 (2337).

The motion compensated image 2355 is generated by resampling the wiped image 2335 in the manner described in FIG. The pixel values 2356 included in the motion-compensated image 2355 accurately reflect the motion of the object at the target time point Ttarget. Thus, the motion artifacts in the finally reconstructed target image can be minimized.

24 is another drawing for explaining the operation of restoring the target image. In Fig. 24, a description overlapping with those in Figs. 22 and 23 is omitted. The image reconstructing unit 720 may perform motion correction in a back-projection process based on the first information. Specifically, the image reconstructing unit 720 may reconstruct the target image by warping the center of the voxel representing the target object, based on the first information, and performing a reverse projection based on the warped voxel position. Here, a voxel represents one unit space in a virtual three-dimensional lattice space for imaging a target object. FIG. 24 illustrates an example in which a virtual space for imaging a subject is shown as pixels that are two-dimensional grid space instead of three-dimensional grid space voxels.

Specifically, the image restoring unit 720 uses a motion vector field from the target point of time Ttarget to each viewpoint, and when a pixel value at a predetermined position in the image to be reconstructed is affected by motion at each point in time, and to look up a value from a pixel in the detector array. In view of the voxel representing the object at the target point, in order to project the filtered projection data at the viewpoint other than the target point back to the voxel, It is necessary to calculate where to move at the point of time. The movement amount of the voxel for compensating the motion of the object can be calculated using the inverse motion vector field of the motion vector field from the corresponding point to the target point. Then, after moving the position of the voxel by the calculated compensation amount, it is possible to calculate which pixel value of the detector array should be fetched.

24, the image reconstructing unit 720 reconstructs an inverse transformed motion vector field 2410 by inversely transforming a motion vector field MVF indicating a motion amount of a target object at a target time point Ttarget, . Then, using the inverse transformed motion vector field 2410, the position of each pixel in the backprojected image 2420 is moved.

For example, based on the motion vectors 2411, 2421, 2422, and 2423 included in the inverse transformed motion vector field 2410, the positions of the pixels in the backprojected image 2420 are respectively moved. Specifically, based on the vector 2421 and the vector 2422, the uppermost right first pixel is moved (2431). Then, based on the motion vector 2423, the first pixel on the right side of the fifth row of the back projection image 2422 is moved (2432). In addition, the pixel position of the region 2427 in which motion is not detected in the inverse transformed motion vector field 2410 is left as it is.

Subsequently, the image restoring unit 720 calculates the position of the detector array when the pixel value of the predetermined pixel is projected in consideration of the moved pixel position, and outputs the projection data filtered at the corresponding position (Voxel), and acquires the backprojected image 2420 by accumulating the value in the corresponding pixel (voxel).

The center of the pixel 2451 is located at the point P1 of the filtered projection data 2210. The position of the center of the pixel 2451 is the center of the filtered projection data 2210, Pixel values. Since the point P1 is located biased toward the uppermost right second pixel 2455 rather than being located at the center of the uppermost right first pixel 2456 of the filtered projection data 2210, the pixel 2456 and the pixel 2455 ). Accordingly, pixel 2451 may have a pixel value of '0.2' as shown, due to pixel '2456 value' 0 'and pixel 2455 value' 1 '.

Similarly, the first right pixel 2452 of row 5 in the backprojected image 2450) is shifted by the movement of the pixel 2432 so that the center of the pixel 2452, as shown, And is positioned on the surface of the second substrate 2452. Thus, pixel 2456 and pixel 2455 are affected at the same rate. Thus, pixel 2451 may have pixel value '0.5', which is the median value of pixel '2456' value '0' and pixel 2455 value '1'.

As described above, the image reconstructing unit 720 may use the inverse transformed field inversion MVF without using the warping described in FIGS. 22 and 23, The corrected target image 2470 can be obtained.

25 is a view showing a restored target image. 25 (a) shows a tomographic image 2510 obtained by the general half-reconstruction method described with reference to Fig. 25 (b) shows a tomographic image 2560 which is motion-compensated using the first information according to an embodiment of the present invention. 25B shows a reconstructed tomographic image 2560 when the target point is the middle point between the first point of time T1 and the second point of time T2.

25A, blurring 2511 and 2512 are generated in a first object 2501 of a target object included in a tomographic image 2510 and blurring 2521 and 2512 are generated in a second object 2502. In this case, 2522) has occurred.

25 (b), in the CT 2560 reconstructed by the tomography apparatus 700 according to the embodiment of the present invention, the first object 2501 and the second object 2502 It may be that no blurring has occurred.

26 is another diagram for explaining the motion amount measurement.

When the data acquisition unit 710 acquires the first image and the second image, if the value a of the first angle interval and the second angle interval is increased, the temporal resolution of the first image and the second image may be degraded have.

In order to prevent temporal resolution degradation of the first image and the second image, when a tomographic image is formed by irradiating an x-ray while rotating around a subject according to a half-reconstruction method, a first a angle A plurality of images are acquired in a plurality of angular intervals included in the interval 2611 and a plurality of images are acquired in a plurality of angular intervals included in the last a angular interval 2612, Can be obtained. The first information can be obtained using the plurality of acquired images. 26, an angular section 2611 corresponding to the first angular section 1411 described in Fig. 14 and an angular section 2612 corresponding to the second angular section 1412 described with reference to Fig. 14 are arranged in two angular sections As shown in FIG.

Referring to FIG. 26, the data obtaining unit 710 obtains the first angular interval 2621 and the third angular interval 2631 included in the first a section 2611 of the one-period angular interval (180 + a degrees) And acquires the first image and the third image. Here, the first angle section 2621 corresponds to the front part a / 2 of the first a section 2611, and the third angular section 2631 corresponds to the rear part a / 2 of the first a section 2611. The second image and the fourth image are acquired in the second angular interval 2622 and the fourth angular interval 2632 included in the last a interval 2612 of the one-period angular interval. Here, the second angle section 2622 corresponds to the front part a / 2 of the last a section 2612, and the fourth angular section 2632 corresponds to the rear part a / 2 of the last section a 2612. The first information indicating the relationship between the amount of movement of the object and the time can be obtained based on the amount of motion between the first image and the second image, and the amount of motion between the third image and the fourth image. Here, the first angle section 2601 and the second angle section 2622 are angular sections having a conjugate angle relationship with each other. The third angle section 2631 and the fourth angle section 2632 are angular sections having a conjugate angle relationship with each other.

The data obtaining unit 710 divides each of the first a section 2621 and the last a section 2612 into three or more angular sections and uses the reconstructed image in each of the plurality of angular sections, 1 information.

The generation of the first information using the two images obtained in the two angle sections having the relationship of the pair of angles has been described in detail with reference to FIG. 13, and a detailed description thereof will be omitted.

FIG. 27 is a view for explaining motion artifacts existing in the reconstructed tomographic image. FIG.

Referring to FIG. 27, tomographic images reconstructed in a conventional tomography apparatus are shown in block 2701, and tomographic images reconstructed in the tomography apparatus 600 and 700 according to an embodiment of the present invention are shown in block 2705.

Referring to the tomographic image 2710 shown in the block 2701, it can be seen that a motion artifact arises due to the motion of the coronary artery in the portion where the coronary artery 2711 is displayed, and the image is blurred . It is also seen that blurring occurred on the surface 2712 due to the movement of the organ.

In addition, the horizontal section 2721 of the blood vessel is blurred and the blood vessel is not clearly restored in the tomographic image 2720, and the region 2731 in which the blood vessel is displayed also has blurring The blood vessels were not clearly restored.

In contrast, in the tomographic image 2750 reconstructed by the tomographic apparatuses 600 and 700 according to the embodiment of the present invention, the coronal artery 2751 is clearly restored, 2752) was clearly restored.

In addition, the horizontal section 2761 of the blood vessel was clearly restored in the tomographic image 2760, and the blood vessel in the area 2771 in which the blood vessel was also displayed in the tomographic image 2770 was clearly restored.

As described above, in the embodiment of the present invention, the first image and the second image having high temporal resolution can be obtained by acquiring the first image and the second image in a part of the angular interval included in the one-period angular interval, The first information indicating the relationship between the amount of motion and the time of the object can more accurately reflect the change in the motion of the object by measuring the amount of motion of the object using the first image and the second image having high resolution. In addition, by restoring the image at the target point of time using the first information, it is possible to restore the image in which the motion artifact is minimized.

28 is another view for explaining motion artifacts present in the reconstructed tomographic image.

Referring to FIG. 28, when the relative time between RR peaks of the ECG signal is expressed in percent (%), restored tomographic images with relative time points of 0%, 20%, and 40% Are shown. Specifically, the block images reconstructed in the conventional tomography apparatus are shown in block 2810, and the tomography images reconstructed in the tomography apparatus 600 and 700 according to the embodiment of the present invention are shown in block 2850. Hereinafter, the tomographic image included in the 2810 block will be referred to as a 'conventional tomographic image', and the tomographic image included in the 2850 block will be referred to as 'original tomographic image'.

28, when comparing the conventional tomographic image 2820 reconstructed at the time when the relative time is 0% with the original tomographic image 2860, the conventional tomographic image 2820 includes areas where blurring due to motion artifacts occurs The motion artifacts in regions 2861 and 2862 corresponding to the blurred regions 2821 and 2822 are remarkably reduced in the tomographic image 2860 of the present embodiment .

When comparing the conventional tomographic image 2830 and the original tomographic image 2870 restored at the time when the relative time is 20%, the conventional tomographic image 2830 includes areas 2831 in which blurring due to motion artifacts occurred It can be seen that the motion artifacts in the area 2871 corresponding to the blurred area 2831 are significantly reduced in the tomographic image 2870 of the present invention.

In addition, when comparing the conventional tomographic image 2840 reconstructed at the time when the relative time is 40% with the original tomographic image 2880, a region 2841 in which blurring due to motion artifacts occurred is included in the conventional tomographic image 2840 However, it can be seen that the motion artifacts in the region 2881 corresponding to the blurred region 2841 are significantly reduced in the tomographic image 2880 of the present invention.

29 is a view showing a user interface screen displayed in the tomography apparatus according to the embodiment of the present invention.

Referring to FIG. 29 (a), the display unit 740 displays a user interface screen 2900 for setting first information. Specifically, the user interface screen 2900 includes a first menu 2930 for setting the relationship between the amount of movement and the time of the object in the first information.

In addition, the user interface screen 2900 may further include a second menu 2901 for displaying first information. The first information displayed on the second menu 2901 is the same as the first information 1380 described in (c) of FIG. 13, so the description overlapping with that of FIG. 13 (c) will be omitted.

The first menu 2930 may include a submenu 2935 for setting the relationship between the amount of movement and the time of the object. The submenu 2935 selects either one of the relationships contained in the submenu 2935 or determines the relationship setting based on whether the relationship between the amount of movement and the time of the object is linear or has a quadratic form You can also type in a formula for yourself.

The first menu 2930 may further include a second submenu 2931 for setting the angular values of the first angular interval and the second angular interval. Accordingly, the user may directly set the angular values of the first angular interval and the second angular interval using the second submenu 2931.

29A shows an example in which the relationship between the amount of motion and the time of the object is set to be linear in the submenu 2935. [

Also, the user interface unit 750 can input second information corresponding to the relationship between the amount of motion and the time of the object through the user interface screen 2900. Specifically, when the user selects the 'linear' item in the submenu 2935 of the user interface screen 2900, the data obtaining unit 710 generates the first information based on the second information. In the above example, if the 'linear' item is selected, the data acquiring unit 710 sets the relationship between the amount of motion and the time of the object to have linearity, and generates the illustrated first information 2920 .

29A and 29B illustrate a case where the display unit 740 displays a user interface screen. However, the user interface screen shown in FIGS. 29A and 29B may be a user interface screen, May be transmitted to an external display unit (not shown) which is generated in the interface unit 750 and is not included in the tomography apparatus 700. Then, the external display unit (not shown) displays the received user interface screen, and the user can view the displayed user interface screen and input information for setting the first information through the user interface unit 750 There will be.

Another example of the user interface screen for setting the first information is shown in Fig. 29 (b).

Referring to FIG. 29 (b), the display unit 740 displays a user interface screen 2950 for setting the first information. Specifically, the user interface screen 2950 includes a first menu 2955 for setting the relationship between the amount of movement and the time of the object in the first information. The second menu 2901 of FIG. 29 (b) is the same as the second menu 2901 of FIG. 29 (a).

Referring to FIG. 29 (b), the first menu 2955 may include a first submenu 2970 for setting a relationship between the amount of movement and the time of the object. The first submenu 2970 includes at least one item 2971, 2972, 2973, 2974 directly displaying the first information as shown.

The user can select any one of the items 2971, 2972 and 2973 included in the first submenu 2970 using the selection cursor 2982. [ 29B shows an example in which the first item 2971 is selected and the first item 2971 is selected in the second menu 2901 and the first information 2920 is shown in the second menu 2901 Can be set together.

In addition, the first menu 2950 may further include a second submenu 2960 for setting the angular values of the first angular interval and the second angular interval. The second submenu 2960 includes a plurality of items having a certain angle value as shown and the user can select one of the items included in the second submenu 2960 using the selection cursor 2981 Can be selected. In FIG. 29 (b), '60 degrees' in the second submenu 2960 is selected as an angle value of the first angular interval and the second angular interval.

In addition to the user interface screens 2900 and 2950 shown in FIGS. 29A and 29B, various types of user interface screens may be created and displayed to set the first information.

In addition, the data acquisition unit 710 may automatically set the angular values of the first angular interval and the second angular interval. In addition, the data acquisition unit 710 may automatically set the graph format of the first information.

30 is another drawing showing a user interface screen displayed in the tomography apparatus according to the embodiment of the present invention.

Referring to FIG. 30, the display unit 740 may display a user interface screen 3000 including a menu for setting a target time point Ttarget.

Referring to FIG. 30, the menu may include at least one of a first sub-menu 3020 and a second sub-menu 3030 to set a target time point.

Specifically, the first sub-menu 3020 may include a one-period angular section rotated around the target object 3022 in the form of coordinates. The user can select the target point by selecting the predetermined point or predetermined point included in the one-week angular interval through the first sub-menu 3020 using the cursor 3021. [

In addition, the second submenu 3030 may include information indicating one-degree angular intervals including the first information. Here, since the second submenu 3030 corresponds to the diagram shown in FIG. 13C, a description that is the same as that in FIG. 13C will be omitted. The user can select the target point by selecting the predetermined point or predetermined point included in the one-week angular interval through the second submenu 3030 using the cursor 3031. [

When both the first submenu 3020 and the second submenu 3030 are displayed in the user interface screen 3000, the first submenu 3020 and the second submenu 3030 A cursor (e.g., a cursor) (e.g., a cursor) is selected at a point corresponding to the selected target point in the other of the first submenu 3020 and the second submenu 3030 when the target point of time is selected using a cursor , 3031) may be displayed.

Also, the user interface screen 3000 can display the target image 3010 corresponding to the selected target time point.

Accordingly, the user can easily set the target time point using the user interface screen 3000. [ The target image 3010 is displayed on the user interface screen 3000. If there is a surface uncertainty or a video error at a site to be observed, .

31 is another diagram showing a user interface screen displayed in the tomography apparatus according to the embodiment of the present invention. Specifically, FIG. 31 (a) is a diagram for explaining the setting of a region of interest. FIG. 31 (b) is a view for explaining a configuration for setting a position or a view angle of the first angular interval and the second angular interval according to the set interest region.

The display unit 740 can display a medical image. Here, the medical image may be a medical image such as a scout image, a tomographic image, an MRI image, an X-ray image, or an ultrasound image.

The user interface unit 750 can set a predetermined region of the medical image from the user as a region of interest.

31 (a), a tomographic image 3110 is shown as a medical image 3100 displayed on the display unit 740, for example.

The user can set a region of interest (ROI) through the user interface unit 750. In addition, the data obtaining unit 710 may automatically extract a region requiring a precise image reading such as a suspected disease site in the medical image, and may set the extracted region as a region of interest.

The data obtaining unit 710 may extract a surface included in the ROI, and may set the first angle interval and the second angle interval based on the extracted surface direction. Specifically, the data obtaining unit 710 may extract the surfaces 3171 and 3172 included in the region of interest 3120 and obtain a view angle corresponding to the extracted surface. Then, at least one of a first angular interval, a second angular interval, a start point of a one-week angular interval, an end point of one-week angular interval, and a target point is set according to the acquired viewing angle, The first image and the second image can be obtained in each of the first angular interval and the second angular interval.

As described with reference to Figs. 16 and 17, the direction of the surface to be sampled clearly varies depending on the beam direction of the irradiated x-ray. Thus, by adjusting the orientation of the x-ray beam along the direction of the surface included in the region of interest 3120, the surfaces included in the region of interest 3120 can be more clearly sampled.

31 (b), the data obtaining unit 710 obtains the directions 3161 and 3162 corresponding to the surfaces 3171 and 3172 included in the region of interest 3120 or the X- A view angle of the display unit 106 can be set. Then, the positions of the first angular section and the second angular section are set according to the set direction or the viewing angle. For example, if the directions in which the surfaces 3171 and 3172 extend are shown in the directions 3161 and 3162, the first angular interval 3151 and the second angular interval 3152 correspond to the directions 3161 and 3162, Can be set. Accordingly, an x-ray may be irradiated on the left side of the region of interest 3120 to obtain a first image, and an x-ray may be irradiated on the right side of the region of interest 3120 to obtain a second image.

The data acquisition unit 710 may generate the first information using the first image and the second image.

As described above, by setting the first angular interval and the second angular interval based on the directions of the surfaces included in the ROI, the surfaces included in the ROI can be more clearly sampled, Can be increased.

In addition, the image reconstructing unit 720 may calculate the angles of the first angular interval, the second angular interval, the starting point of the one-week angular interval (the angular point corresponding to t = 0) , An end point (an angle point corresponding to t = end), and a target point of time T_target. For example, the first angular interval and the second angular interval may be set so that motion measurement can be performed for a direction in which a motion of a target occurs frequently.

31 (a), when the target object is a person and the tomographic image to be acquired is a tomographic image of a cross-section, for example, movement in the front direction 3330 of the person due to respiration, heartbeat, .

More specifically, in order to observe the movement of the person's front direction 3330, a lot of movement occurs in the front direction 3330 of the person, (E. G., 3171) extending in a direction adjacent to the < / RTI > That is, if a lot of movement in the front direction 3330 occurs, the surface 3171 must be clearly imaged in the first and second images used to obtain the first information. The amount of motion of the object in the front direction 3330 can be accurately grasped by comparing the surface 3171 imaged in the first image with the surface 3171 imaged in the second image to obtain the first information to be.

Accordingly, in order to measure the amount of movement of the object in the front direction 3330, the first angle section and the second angle section are divided into a first angle section 3181 and a second angle section 3182 Can be set. The movement of the object in the direction 3183 (the same direction as the front direction 3330) perpendicular to the X-ray irradiation directions 3161 and 3162 in the first angle section 3181 and the second angle section 3182 It is possible to acquire the first information for the first time. If motion compensation is performed by applying the amount of motion in the first direction 3183, the target image corresponding to the target time point can be restored more accurately.

Further, the tomographic imaging apparatus 700 may perform the following operations.

The data obtaining unit 710 reconstructs at least one or more reference images for estimating the motion of the object by rotating and rotating at angular intervals less than one rotation about the object and acquires first information indicating the amount of motion of the object do. Here, the 'angular section of less than one rotation' may correspond to the same one-angular section. Also, at least one reference image may be a partial angle image obtained in a partial angle section included in one-week angular interval. Specifically, the reference image may be at least one of the first image 1310 and the second image 1320 described with reference to FIG. The first and third images acquired in the first angular interval 2621 and the third angular interval 2631 and the second angular interval 2622 and the fourth angular interval 2632 The second image and the fourth image acquired from each of the first and second images.

Specifically, the data obtaining unit 710 obtains the first image corresponding to the first viewpoint through the partial angle reconstruction and obtains the second image corresponding to the second viewpoint. Then, based on the amount of motion between the first image and the second image, the first information indicating the relationship between the amount of motion and the time of the object can be obtained.

The image reconstructing unit 720 performs the motion compensation operation described above and uses the first information acquired by the data acquiring unit 710 to generate a target image in which the motion artifact corresponding to the target point in one week is reduced Restore.

Further, the tomographic imaging apparatus 700 may perform the following operations.

The data acquiring unit 710 acquires a first image and a second image corresponding to the first viewpoint and the second viewpoint, respectively, which represent a part of the surface on which the object is to be formed. Then, the first information indicating the motion of the object is obtained using the acquired first and second images. Here, the first information may be information indicating a relationship between a motion amount of a surface forming a target object corresponding to a motion vector field between the first and second images and a time.

The image restoring unit 720 restores the target image using the first information.

Further, the tomographic imaging apparatus 700 may perform the following operations.

The data obtaining unit 710 obtains the first partial image and the second partial image using the data obtained in each of the start angle section and the end angle section opposed to the start angle section. The first information indicating the relationship between the amount of motion and the time of the surface of the object corresponding to the motion vector field between the first partial image and the second partial image is acquired.

The image restoring unit 720 restores the target image indicating the target object at the target point based on the first information.

Further, the tomographic imaging apparatus 700 may perform the following operations.

The data acquiring unit 710 obtains first and second images corresponding to the first and second viewpoints, respectively, representing a part of the surface on which the object is to be formed by performing tomographic imaging of the object, And acquires first information indicating the motion of the object using the image.

Then, the image restoring unit 720 warps at least one of the images obtained by projecting the data and raw data required for the half restoration back to the filter based on the first information, and outputs the target image representing the object at the target point Restore.

Further, the tomographic imaging apparatus 700 may perform the following operations.

The data acquiring unit 710 acquires tomographic images of a target object and acquires data of the first angular section and the second angular section corresponding to the first viewpoint and the second angular section facing the first angular section, The first image and the second image are acquired. Then, based on the first image, the second image, and the additional information, the first information indicating the amount of motion of the object is obtained.

The image restoring unit 720 restores the target image indicating the target object at the target point based on the first information.

Specifically, in the tomographic imaging of the object, even if the object does not move itself, movement may be caused to the object by an external factor. For example, when vibration, movement, or shaking of a table and / or a tomography apparatus in which a target object is caused to move occurs, the target object may vibrate, move or shake. The occurrence of the motion of the object by such an external factor causes blurring in the imaging of the object.

As described above, when blurring occurs in the imaging of the object due to an external factor, the data acquisition unit 710 acquires the first image and the second image, and the first information, It is possible to remove the imaging blurring of the image sensor.

Further, the tomographic imaging apparatus 700 may perform the following operations.

The data acquiring unit 710 acquires tomographic images of a target object and acquires data of the first angular section and the second angular section corresponding to the first viewpoint and the second angular section facing the first angular section, The first image and the second image are acquired. Then, additional information, which is information on the motion occurring in the object during the tomography, is acquired. Then, based on the first image, the second image, and the additional information, the first information indicating the amount of motion of the object is obtained.

The image restoring unit 720 restores the target image indicating the target object at the target point based on the first information.

Specifically, in the tomographic imaging of the object, additional information can be used to accurately predict the motion pattern of the object. For example, if the object is a heart, if the movement of the heart suddenly pulsates suddenly or occurs in an unexpected pattern, additional information, which is information on the motion of the heart, is acquired and the first information is set .

In addition, when the object does not move, but a motion such as vibration, movement, or shaking of the tomographic apparatus causing movement occurs on the table or object on which the object is located, movement may be caused by the external factors of the object. In this case, the first information can be set by acquiring additional information, which is information about motion generated in the object during the tomography by external factors, and reflecting the additional information.

For example, the monitoring device for monitoring the motion of the object, such as a digital stethoscope, can be used to monitor the motion of the object during tomography to obtain additional information. The shape of the graph can be set in the first information by reflecting the motion pattern of the object generated in the one-week angular interval acquired by the digital stethoscope. For example, according to the additional information, if the movement pattern of the object has a linear pattern in one angular interval, the data obtaining unit 710 may set the first information in the form as shown in item 2971 of FIG. 29 There will be. As another example, according to the additional information, when the object moves fast in the initial section of the one-week angular interval and the movement of the object hardly occurs after the initial interval of the one-week angular interval, .

Further, the tomographic apparatus 700 may further include a monitoring unit (not shown) for acquiring additional information. In this case, the data acquisition unit 710 may receive the additional information from the monitoring unit (not shown), and may acquire the first information based on the received additional information. Here, the monitoring unit (not shown) may include various types of devices for monitoring the movement of the object, and may include, for example, a digital stethoscope, a motion detection sensor, an image sensor for detecting motion .

In addition, the tomographic apparatus 700 may not include a monitoring unit (not shown) for acquiring additional information, and may receive only additional information from an externally connected monitoring unit (not shown).

As described above, the motion amount generated in one angular interval is measured based on the first image and the second image, and when the motion pattern of the object in one angular interval is set based on the additional information, It is possible to obtain the first information that more accurately represents this.

32 is a flowchart illustrating a tomographic image reconstruction method according to an embodiment of the present invention. The operations of the steps included in the tomographic image reconstruction method 3200 according to an embodiment of the present invention are the same as those of the tomographic image reconstruction method 3200 included in the tomographic imaging apparatuses 600 and 700 according to the embodiment of the present invention described with reference to FIGS. The operation is the same as that of the configuration. Therefore, in explaining the tomographic image restoration method 3200, the description overlapping with FIGS. 1 to 31 will be omitted.

Referring to FIG. 32, a tomographic image reconstruction method 3200 according to an embodiment of the present invention tomographs a target (Step 3210). Specifically, a first image, which is a partial image, is acquired using data obtained in a first angular interval corresponding to the first viewpoint through tomography, and a second image is acquired using data acquired in a second angular interval corresponding to the second viewpoint And acquires a second image which is a partial image (Step 3210). The operation of step 3210 may be performed in the data obtaining unit 710 of the tomographic apparatus 700. Here, each of the first angular interval and the second angular interval may be less than 180 degrees.

In operation 3220, first information indicating the amount of motion of the object at a time point is obtained based on the amount of motion between the first image and the second image acquired in operation 3210. Specifically, the first information can be obtained by comparing only the first image and the second image. The operation of step 3220 may be performed in the data obtaining unit 710 of the tomographic apparatus 700. Here, the first information may be the amount of motion of the object at the time point of time. In addition, when a moving object is photographed, at least one of the size, position, and shape of the object included in the image in the first image and the second image may be different.

Specifically, the first information may be information indicating the amount of movement of the surface forming the object. The first information may be information indicating a relationship between a motion amount of a surface forming a target object corresponding to a motion vector field between the first and second images and a time.

In acquiring the first information, a user interface screen for setting the first information is displayed, and second information corresponding to the relationship between the amount of movement and the time of the object in the first information is displayed on the displayed user interface screen Can be input. Then, the first information can be generated based on the second information.

26, when acquiring the first image and the second image (Step 3210), when the subject rotates and radiates X-rays to obtain a tomographic image, as shown in FIG. 26, Acquiring a first partial image and a third partial image in each of a first angular section 2621 and a third angular section 2631 included in the first a section 2611 of the section, And acquiring the second partial image and the fourth partial image in the second angular interval 2622 and the fourth angular interval 2632 included in the interval 2612, respectively. The first information indicating the relationship between the amount of motion and the time of the object can be obtained based on the amount of motion between the first partial image and the second partial image, and the amount of motion between the third partial image and the fourth partial image. Here, the first angular interval and the second angular interval are in a relation of conjugate angles, and the third angular interval and the fourth angular interval are in a relation of conjugate angles.

In addition, the tomographic image reconstruction method 3200 may further include a step of displaying a medical image before step 3210, and a step of setting a region of interest in the medical image (not shown). In operation 3210, a step of extracting a surface line included in a region of interest, a step of acquiring a view angle corresponding to the extracted surface line, setting a first angle section and a second angle section according to a viewing angle, And obtaining the first image and the second image in the first angle section and the second angle section, respectively.

In addition, the tomographic image restoration method 3200 may further include displaying a user interface screen including a menu for setting a target time point (not shown).

In operation 3230, the target image corresponding to the target point of time between the first point of view and the second point of view is reconstructed based on the first information obtained in operation 3220. The operation of step 3230 may be performed by the image restoring unit 720 of the tomographic apparatus 700. Specifically, based on the first information, the target image can be acquired through motion compensation based on the amount of motion of the object at the target point of time.

Further, in the restored target image, the degree of motion correction of the target object included in the target image may be changed according to the target time.

Also, when the target image corresponds to the intermediate angle between the first angle section and the second angle section, the motion compensation of the object can be performed better than when the target image does not correspond to the intermediate angle.

33 is a flowchart illustrating a tomographic image reconstruction method according to another embodiment of the present invention. The operational configuration of the tomographic image restoration method 3300 according to another embodiment of the present invention is the same as that of the tomographic imaging apparatuses 600 and 700 according to the embodiment of the present invention described with reference to FIGS. Therefore, in explaining the tomographic image restoration method 3300, the description overlapping with FIGS. 1 to 31 will be omitted.

Referring to FIG. 33, a tomographic image reconstruction method 3300 according to another embodiment of the present invention tomographs a moving object (step 3310). Specifically, a first image and a second image, which are partial images corresponding to the first and second viewpoints, respectively, representing the same portion of the surface forming the object, are obtained. Specifically, a tomographic image is obtained by rotating the object at an angular interval of less than one rotation, and a first partial angle corresponding to the first viewpoint and a second partial angle corresponding to the second viewpoint, And acquires the first image and the second image using the data obtained in each of the two angle sections. The operation of step 3310 may be performed in the data obtaining unit 710 of the tomography apparatus 700.

In operation 3320, first information indicating the motion of the object is acquired using the first image and the second image obtained in operation 3310. The operation of step 3320 may be performed in the data acquisition unit 710 of the tomography apparatus 700. Here, the first information may be information indicating a relationship between a motion amount of a surface forming a target object corresponding to a motion vector field between the first and second images and a time.

The corresponding target image is restored based on the first information obtained in step 3320 (step 3330). Specifically, the motion compensation described with reference to Figs. 19 to 24 can be performed to restore the target image. The operation of step 3330 may be performed in the image reconstruction unit 720 of the tomographic apparatus 700.

As described above, according to the tomographic apparatus and the tomographic image reconstruction method according to the embodiment of the present invention, the angular section of one rotation, that is, the angular section corresponding to 180+ additional angles, Thereby restoring an image in which motion artifacts are reduced. Accordingly, the amount of data for reconstructing the motion-compensated image is minimized to the amount of data corresponding to the 180+ pan angle interval, and the time required for data acquisition is reduced, compared to the amount of data required for conventional motion compensation. Accordingly, the amount of x-rays irradiated to the patient can also be reduced.

In addition, the tomographic apparatus and the tomographic image reconstruction method according to the embodiment of the present invention acquire information on the motion of the object through the first and second images having high temporal resolution as described above, It is possible to accurately reflect the motion state of the object and restore the target image with high temporal resolution. In addition, motion compensation is performed effectively on the surface imaged by the projection data obtained in the start angular section and the end angular section within one-week angular section in which blurring occurs most severely, thereby restoring the target image with high temporal resolution have. Accordingly, it is possible to restore an image in which motion artifacts are minimized.

The above-described embodiments of the present invention can be embodied in a general-purpose digital computer that can be embodied as a program that can be executed by a computer and operates the program using a computer-readable recording medium.

The computer readable recording medium may be a magnetic storage medium such as a ROM, a floppy disk, a hard disk, etc., an optical reading medium such as a CD-ROM or a DVD and a carrier wave such as the Internet Lt; / RTI > transmission).

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100: System
102: Gantry
104: Rotating frame
105: Table
106: X-ray generator
108: X-ray detector
110:
112: collimator
114: Spawning prevention grid
118:
120: Data transmission unit
124:
126:
128:
130:
132:
134: Server
136: Medical devices
301: Network
600: Tomographic apparatus
610:
620:
700: Tomographic apparatus
710:
720:
730: Gantry
740:
750: user interface section
760:
770:

Claims (84)

A first image, which is a partial image, and a second image, which correspond to a first angular interval and a second angle corresponding to the first angle, and which are obtained in each of the second angular intervals facing the first angular interval, A data acquiring unit acquiring a second image, acquiring first information indicating a motion amount of the object using the first image and the second image; And
And an image restoring unit for restoring, based on the first information, a target image indicating the target object at the target time point. 2. The method of claim 1, wherein each of the first angular interval and the second angular interval
180 degrees. ≪ / RTI > The method of claim 1, wherein the first information
And comparing the first image and the second image with each other. 2. The method according to claim 1, wherein in the first image and the second image,
Wherein at least one of a size, a position, and a shape of the object included in the image is different. The method according to claim 1, wherein, in the target image,
And the degree of motion correction of the object included in the target image varies according to the target time point. 2. The method according to claim 1,
Wherein motion compensation of the object is performed more easily than when the target point does not correspond to the intermediate angle, when the target point corresponds to an intermediate angle between the first angle section and the second angle section. The method of claim 1, wherein the first information
And information indicating the amount of movement of the surface forming the object. The method of claim 1, wherein the first information
Wherein the motion vector information is information corresponding to a motion vector field between the first image and the second image and is information indicating a motion amount of a surface forming the object corresponding to each time point. 9. The method of claim 8,
Wherein the measurement is performed using non-rigid registration. 9. The method of claim 8, wherein the first information
Wherein the motion amount corresponding to the motion vector field has a linear relationship with the time point. The apparatus of claim 1, wherein the data obtaining unit
Acquiring the first image and the second image using the RO data acquired by tomographic imaging in a one-week angular interval less than one rotation,
Wherein the first angular section and the second angular section are respectively a start section and an end section of the periodic angular section. The apparatus of claim 1, wherein the image restoration unit
Wherein the target image is reconstructed using a plurality of projection data corresponding to a plurality of views that are RO data obtained by performing tomographic imaging while rotating at less than one rotation. The method of claim 1, wherein the first information
And motion information on all directions of the surface of the object imaged by the first image and the second image. The apparatus of claim 1, wherein the image restoration unit
Predicts a motion amount of the object at the target point based on the first information, and restores the target image based on the predicted motion amount. The apparatus of claim 1, wherein the image restoration unit
And reconstructs the target image by warping a plurality of partial images representing a part of the target object based on the first information. The apparatus of claim 1, wherein the image restoration unit
Wherein a center of a voxel representing the object is waved based on the first information, and a backward projection operation is performed based on the position of the wobbled voxel to restore the target image. The method according to claim 1,
And a user interface unit for receiving a relationship between the amount of movement and the time of the object in the first information through a user interface screen for setting the first information,
The data obtaining unit
And acquires the first information based on the relationship. The apparatus of claim 1, wherein the data obtaining unit
Wherein the tomographic imaging is performed at 180 degrees + additional angular intervals according to a half reconstruction method using a parallel beam that has been rebounded. The method according to claim 1,
The data obtaining unit
180 degrees + additional angle section,
The additional angle
And has a value of approximately 30 to 70 degrees. The method according to claim 1,
Further comprising a display unit for displaying a user interface screen including a menu for setting the target time point. The method according to claim 1,
Further comprising a display unit for displaying a screen including at least one of a first information, a target viewpoint, a target image, and a user interface screen for setting the first information. The apparatus of claim 1, wherein the data obtaining unit
The method includes dividing the projection data acquired by the tomographic photographing into a plurality of conjugate view sections rotating about the object, obtaining a partial image pair including the first image and the second image in each of the plurality of conjugate view sections And acquires the first information using a plurality of partial image pairs each corresponding to the plurality of conjugate view sections. The method according to claim 1,
A display unit for displaying a medical image; And
And a user interface unit configured to set an area of interest of the medical image,
The data obtaining unit
The method of claim 1, further comprising: extracting at least one surface included in the region of interest, and determining at least one of the first angle section, the second angle section, the starting point of the one- And the target point of time, and acquires the first image and the second image in each of the first angle section and the second angle section corresponding to the setting, and the first image and the second image, 2 image to obtain the first information indicating the amount of motion of the object. The apparatus of claim 1, wherein the data obtaining unit
A first angular interval, a second angular interval, a first point of view, a second point of view, a start point of a one-week angular interval, an end point of a one-week angular interval, And the at least one of the plurality of pixels is set to be at least one of the plurality of pixels. 2. The method according to claim 1,
A heart, an abdomen, a uterus, a brain, a breast, and a liver. 2. The method according to claim 1,
Wherein the heart comprises a heart represented by a surface, the heart comprising at least one tissue having different brightness values within a predetermined region. The apparatus of claim 1, wherein the data obtaining unit
Wherein the tomography is performed according to at least one of an axial scan method and a helical scan method. The apparatus of claim 1, wherein the data obtaining unit
Acquiring additional information, which is information on a motion occurring in at least one of the object and the outside of the object during the tomography, and calculating a motion amount of the object based on the first image, the second image, And acquires first information indicating the first information. The apparatus of claim 1, wherein the data obtaining unit
Acquiring a plurality of partial image pairs including the first image and the second image for imaging the same part of the object using a helical scanning method and acquiring the first information using the plurality of partial image pairs And the tomographic image capturing device. Obtaining a first image and a second image which are partial images corresponding to a first viewpoint and a second viewpoint, respectively, which represent the same portion of a surface forming the object, A data acquiring unit acquiring first information indicating a motion of the object using two images; And
And an image reconstruction unit for reconstructing the target image using the first information. 31. The apparatus of claim 30, wherein each of the first image and the second image comprises:
Wherein the partial image reconstructed using the data obtained in the first angular section and the second angular section is less than 180 degrees. 32. The method of claim 30, wherein the first information
And comparing the first image and the second image with each other. The method of claim 30, wherein the first image and the second image are
Wherein at least one of a size, a position, and a shape of the object included in the image is different. 32. The method of claim 30, wherein the first information
Wherein the motion vector information is information corresponding to a motion vector field between the first image and the second image and is information indicating a motion amount of a surface forming the object corresponding to each time point. 31. The apparatus of claim 30, wherein the data obtaining unit
The tomographic images are taken at one angular interval of less than one rotation,
Wherein the first point of time corresponds to the beginning period of the one-period angular interval and the second point of time corresponds to the end of the one-period angular interval. 31. The image processing apparatus of claim 30, wherein the image restoration unit
And restores a target image indicating the target object at a target point between the first point and the second point of time based on the first information. 37. The method of claim 36, further comprising:
And the degree of motion correction of the object included in the target image varies according to the target time point. 37. The method of claim 36,
Wherein when the target point of time corresponds to an intermediate angle between the first angle section and the second angle section, motion compensation of the object is performed better than when the target point of time does not correspond to the intermediate angle. 31. The image processing apparatus of claim 30, wherein the image restoration unit
Wherein the target image is reconstructed using a plurality of projection data corresponding to a plurality of views that are RO data obtained by performing tomographic imaging while rotating at less than one rotation. 32. The method of claim 30, wherein the first information
Wherein the information indicating the amount of movement of the surface of the object during the first time point to the second time point. A moving image of a moving object is obtained by using the data obtained in each of the first angular section corresponding to the first viewpoint and the second angular section corresponding to the second viewpoint and facing the first angular section, And acquiring a second image;
Acquiring first information indicating a motion amount of the object at a time point using the first image and the second image; And
And reconstructing a target image representing the target object at a target point based on the first information. 42. The method of claim 41, wherein each of the first angular section and the second angular section
180 degrees. ≪ / RTI > 42. The method of claim 41, wherein obtaining the first information comprises:
And comparing the first image and the second image to obtain the first information. 42. The method of claim 41, wherein in the first image and the second image,
Wherein at least one of a size, a position, and a shape of the object included in the image is different. The method of claim 41, wherein, in the target image,
Wherein the degree of motion correction of the target object included in the target image is changed according to the target time point. 42. The method of claim 41,
Wherein when the target point of time corresponds to an intermediate angle between the first angle interval and the second angle interval, the motion compensation of the object is performed better than when the target point of time does not correspond to the intermediate angle. . 42. The method of claim 41, wherein the first information
And information indicating the amount of motion of the surface forming the object. 42. The method of claim 41, wherein the first information
Wherein the motion vector information is information corresponding to a motion vector field between the first image and the second image and is information indicating a motion amount of a surface forming the object corresponding to each time point, . 49. The apparatus of claim 48,
Wherein the non-rigid registration is performed using non-rigid registration. 49. The method of claim 48, wherein the first information is
Wherein the motion amount corresponding to the motion vector field has a linear relationship with the time point. 42. The method of claim 41, wherein obtaining the first and second images further comprises:
And acquiring the first image and the second image using the RO data obtained by tomographic imaging at one angular interval that is less than one rotation,
Wherein the first angular interval and the second angular interval are a start interval and an end interval of the periodic angular interval, respectively. The method of claim 41, wherein restoring the target image comprises:
And reconstructing the target image using a plurality of projection data corresponding to a plurality of views that are RO data obtained by performing tomographic imaging while rotating at less than one rotation. 42. The method of claim 41, wherein the first information
And motion information on all directions of the surface of the object imaged by the first image and the second image. The method of claim 41, wherein restoring the target image comprises:
Estimating a motion amount of the object at the target point based on the first information, and restoring the target image based on the predicted motion amount. The method of claim 41, wherein restoring the target image comprises:
And reconstructing the target image by warping a plurality of partial images representing a part of the target object based on the first information. The method of claim 41, wherein restoring the target image comprises:
And reconstructing the target image by performing a backprojection operation based on the position of the wobbled voxel and wiping a center of a voxel representing the target based on the first information, How to restore. 42. The method of claim 41,
Further comprising the step of receiving, from the user interface screen for setting the first information, relationship information between the amount of movement and the time of the object,
The step of obtaining the first information
And acquiring the first information based on the relationship. 42. The method of claim 41, wherein obtaining the first and second images further comprises:
And performing the tomography in 180 degrees + additional angular intervals according to a half reconstruction method using a parallel beam that has been rebounded. 42. The method of claim 41,
Further comprising obtaining projection data corresponding to 180 degrees + additional angle section,
The additional angle
And a value of approximately 30 to 70 degrees. 42. The method of claim 41,
Further comprising the step of displaying a user interface screen including a menu for setting the target time point. 42. The method of claim 41,
Further comprising the step of displaying a screen including at least one of a first information, a target viewpoint, a target image, and a user interface screen for setting the first information. 42. The method of claim 41,
The step of acquiring the first image and the second image
Dividing the projection data obtained by the tomography into a plurality of conjugate view sections rotating around the object and acquiring a partial image pair including the first image and the second image in each of the plurality of conjugate view sections Wherein the obtaining of the first information comprises:
And acquiring the first information using a plurality of the partial image pairs each corresponding to the plurality of conjugate view sections. 42. The method of claim 41,
Displaying a medical image; And
Further comprising the step of setting an area of interest of the medical image,
The step of acquiring the first image and the second image
The method of claim 1, further comprising: extracting at least one surface included in the region of interest, and determining at least one of the first angle section, the second angle section, the starting point of the one- And at least one of the target points, and acquiring the first image and the second image in each of the first angle section and the second angle section corresponding to the setting Wherein the reconstructed image is reconstructed by reconstructing the tomographic image. 42. The method of claim 41,
A first angular interval, a second angular interval, a first point of view, a second point of view, a start point of a one-week angular interval, an end point of a one-week angular interval, The method further comprising the step of setting at least one of the plurality of images. 42. The method of claim 41,
A heart, an abdomen, a uterus, a brain, a breast, and a liver. 42. The method of claim 41,
Wherein the heart comprises at least one tissue having a different brightness value within a predetermined region, wherein the heart comprises at least one tissue represented by a surface. 42. The method of claim 41,
Further comprising the step of performing the tomography according to at least one of an axial scan method and a helical scan method. 42. The method of claim 41,
Further comprising the step of acquiring additional information, which is information on a motion occurring in at least one of the object and the outside of the object during the tomography,
The step of obtaining the first information
And acquiring first information indicating the amount of motion of the object based on the first image, the second image, and the additional information. 42. The method of claim 41,
The step of acquiring the first image and the second image
Acquiring a plurality of partial image pairs including the first image and the second image for imaging the same part of the object using a helical scanning method,
The step of obtaining the first information
And acquiring the first information using the plurality of partial image pairs. Obtaining a first image and a second image which are partial images corresponding to a first viewpoint and a second viewpoint, respectively, which represent the same portion of a surface forming the object, by tomographic imaging of a moving object;
Obtaining first information indicating a motion of the object using the first image and the second image; And
And reconstructing the target image using the first information. 71. The apparatus of claim 70, wherein each of the first image and the second image comprises
Wherein the partial image reconstructed using the data obtained in the first angular interval and the second angular interval is less than 180 degrees. 71. The method of claim 70, wherein obtaining the first information comprises:
And comparing the first image and the second image to obtain the first information. The method of claim 70, wherein the first image and the second image are
Wherein at least one of a size, a position, and a shape of the object included in the image is different. The method of claim 70, wherein the first information
Wherein the motion vector information is information corresponding to a motion vector field between the first image and the second image and is information indicating a motion amount of a surface forming the object corresponding to each time point, . 71. The method of claim 70,
The step of acquiring the first image and the second image
And performing the tomography at one angular interval that is less than one rotation,
Wherein the first viewpoint corresponds to a start interval of the one-period angular interval and the second viewpoint corresponds to an end interval of the one-period angular interval. 71. The method of claim 70, wherein restoring the target image comprises:
And reconstructing a target image indicating the target object at a target point between the first point and the second point of view based on the first information. 76. The method of claim 76, further comprising:
Wherein the degree of motion correction of the target object included in the target image is changed according to the target time point. The method of claim 76,
Wherein when the target point of time corresponds to an intermediate angle between the first angle interval and the second angle interval, the motion compensation of the object is performed better than when the target point of time does not correspond to the intermediate angle. . 71. The method of claim 70, wherein restoring the target image comprises:
And reconstructing the target image using a plurality of projection data corresponding to a plurality of views that are RO data obtained by performing tomographic imaging while rotating at less than one rotation. The method of claim 70, wherein the first information
Wherein the information indicating the amount of movement of the surface of the object during the first time point to the second time point. A first partial image and a second partial image, which are partial images, are obtained by using tomographic images of a moving object and data obtained in each of a start angle section and an end angle section opposed to the start angle section, A data acquiring unit acquiring first information indicating a relationship between a motion amount and a time of a surface of the object corresponding to the motion vector field between the second partial images; And
And an image restoring unit for restoring, based on the first information, a target image indicating the target object at the target time point. Obtaining a first image and a second image which are partial images corresponding to a first viewpoint and a second viewpoint, respectively, which represent the same portion of a surface forming the object, A data acquiring unit acquiring first information indicating a motion of the object using two images; And
And an image restoration unit for restoring, based on the first information, at least one of the data required for half-recovery and the image obtained by projecting the filtered data backward by filtering to restore the target image representing the object at the target time point And the tomographic image capturing device. A first image and a second image, which are partial images, are obtained by using tomographic images of the object and data obtained in each of the first angular interval and the second angular interval corresponding to the second angle and facing the first angular interval, A data acquiring unit acquiring second images, acquiring first information indicating a motion amount of the object using the first image and the second image; And
And an image restoring unit for restoring, based on the first information, a target image indicating the target object at the target time point. The moving object is photographed, and the data obtained in each of the first angular section and the second angular section corresponding to the second viewpoint and corresponding to the first angular section are used to obtain the first image and the second image, A data acquiring unit acquiring second images, acquiring first information indicating a motion amount of the object using the first image and the second image; And
And an image restoring unit for restoring, based on the first information, a target image indicating the target object at the target time point.

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