JP2013183764A - X-ray ct apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus capable of displaying an image allowing an operator to easily confirm an insertion path of a puncture needle.SOLUTION: An X-ray CT apparatus in an embodiment includes an MPR image creating part, a setting part, a specifying part, a sectional image creating part, and a display control part. The MPR image creating part creates a first MPR image showing a cross section in a prescribed direction for volume data and a second MPR image showing a cross section in a direction different from the prescribed direction. The setting part is used for setting an insertion path of a puncture needle into a subject based on the first MPR image. The specifying part specifies an image region corresponding to the insertion path in the first MPR image and in the second MPR image respectively. The sectional image creating part creates a sectional image of a cross section orthogonally crossing a cross section of the first or second MPR image and along the image region in the MPR image for the first and second MPR images in which the image regions are specified respectively. The display control part switches and displays the sectional image in a display part.

Description

  Embodiments described herein relate generally to an X-ray CT apparatus.

  An X-ray CT (Computed Tomography) apparatus is an apparatus that scans a subject using X-rays and processes the collected data by a computer, thereby imaging the inside of the subject.

  Specifically, the X-ray CT apparatus irradiates the subject a plurality of times from different directions along a circular orbit centered on the subject. The X-ray CT apparatus collects a plurality of detection data by detecting X-rays transmitted through a subject with an X-ray detector. The collected detection data is A / D converted by the data collection unit and then transmitted to the console device. The console device pre-processes the detection data and creates projection data. Then, the console device performs reconstruction processing based on the projection data, and creates tomographic image data or volume data based on a plurality of tomographic image data. Volume data is a data set representing a three-dimensional distribution of CT values corresponding to a three-dimensional region of a subject.

  The X-ray CT apparatus can perform MPR (Multi Planar Reconstruction) display by rendering the volume data in an arbitrary direction. Hereinafter, a cross-sectional image displayed in MPR by rendering volume data may be referred to as an “MPR image”. The MPR image includes, for example, an axial image showing a cross section orthogonal to the body axis, a sagittal image showing a cross section of the subject along the body axis, and a coronal image showing a cross section of the subject along the body axis. There is. Furthermore, an arbitrary cross-sectional image (oblique image) in the volume data is also included in the MPR image. The plurality of created MPR images can be simultaneously displayed on a display unit or the like.

  There is an imaging method called CT fluoroscopy (CTF) that is performed using an X-ray CT apparatus. CT fluoroscopy is an imaging method in which an image relating to a region of interest of a subject is obtained in real time by continuously irradiating the subject with X-rays. In CT fluoroscopy, images are created in real time by reducing the detection data collection rate and reducing the time required for reconstruction processing. CT fluoroscopy is used, for example, for confirming the positional relationship between the tip of a puncture needle and a part from which a specimen is collected during a biopsy, or for confirming the position of a tube when performing a drainage method. The drainage method is a method of draining the body fluid accumulated in the body cavity with a tube or the like.

  When performing a biopsy on a subject while referring to an MPR image based on volume data obtained by CT fluoroscopy, for example, scanning and puncturing may be performed alternately. Specifically, first, an MPR image of the subject is acquired by CT fluoroscopy. A doctor or the like performs puncturing while referring to the MPR image. At this time, for example, in order to confirm the positional relationship between the tip of the puncture needle and the part from which the specimen is collected, CT fluoroscopy is performed again at a stage where puncture is performed to some extent. While referring to the MPR image obtained by another CT fluoroscopy, the doctor or the like further advances the puncture. By repeatedly performing this operation until the biopsy is completed, the biopsy can be reliably performed.

  Moreover, when performing a biopsy by CT fluoroscopy, a puncture plan may be created in advance. The puncture plan is information including the insertion path of the puncture needle into the subject. The puncture plan is set, for example, by drawing an insertion path by an instruction input from a mouse or the like in a CT image acquired in advance before performing CT fluoroscopy. A doctor or the like punctures a subject while referring to a CT image showing an insertion path and an MPR image based on volume data obtained by X-ray scanning each time.

JP 2002-112998 A

  By the way, in order to surely puncture the subject, there is a demand for the operator to confirm the set insertion path from various directions.

  Embodiments have been made to solve the above-described problems, and an object of the present invention is to provide an X-ray CT apparatus capable of displaying an image with which the insertion path of a puncture needle can be easily confirmed.

  The X-ray CT apparatus of the embodiment creates volume data based on the result of scanning a subject with X-rays. The X-ray CT apparatus includes an MPR image creation unit, a setting unit, a specifying unit, a cross-sectional image creation unit, and a display control unit. The MPR image creation unit creates a first MPR image showing a cross section in a predetermined direction with respect to the volume data and a second MPR image showing a cross section in a direction different from the predetermined direction. The setting unit is used to set the insertion path of the puncture needle for the subject based on the first MPR image. The specifying unit specifies an image region corresponding to the insertion path in each of the first MPR image and the second MPR image. The cross-sectional image creation unit creates, for each of the first MPR image and the second MPR image in which the image region is specified, a cross-sectional image that is orthogonal to the cross-section of the MPR image and is along the image region. The display control unit switches and displays the cross-sectional image on the display unit.

1 is a block diagram of an X-ray CT apparatus according to a first embodiment. It is a figure which supplements description of the setting part which concerns on 1st Embodiment. It is a figure which supplements description of the setting part which concerns on 1st Embodiment. It is a figure which supplements description of the setting part which concerns on 1st Embodiment. It is a figure which supplements description of the specific part which concerns on 1st Embodiment. It is a figure which supplements description of the display control part which concerns on 1st Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 1st Embodiment. It is a block diagram of the X-ray CT apparatus which concerns on 2nd Embodiment. It is a figure which supplements description of the preparation part which concerns on 2nd Embodiment. It is a figure which supplements description of the preparation part which concerns on 2nd Embodiment. It is a figure which supplements description of the display control part which concerns on 2nd Embodiment. It is a figure which supplements description of the display control part which concerns on 2nd Embodiment. It is a flowchart which shows the outline | summary of operation | movement of the X-ray CT apparatus which concerns on 2nd Embodiment. It is a figure which supplements description of the display control part which concerns on the modification 1. FIG.

(First embodiment)
With reference to FIGS. 1-5, the structure of the X-ray CT apparatus 1 which concerns on 1st Embodiment is demonstrated. Since “image” and “image data” have a one-to-one correspondence, in the present embodiment, they may be regarded as the same. In the present embodiment, the body axis direction of the subject E is defined as the Z direction (slice direction), the lateral direction orthogonal to the body axis direction is defined as the X direction (channel direction), and the longitudinal direction is defined as the Y direction.

<Device configuration>
As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a bed device 30, and a console device 40.

[Mounting device]
The gantry device 10 is an apparatus that irradiates the subject E with X-rays and collects detection data of the X-rays transmitted through the subject E. The gantry device 10 includes an X-ray generator 11, an X-ray detector 12, a rotating body 13, a high voltage generator 14, a gantry driver 15, an X-ray diaphragm 16, a diaphragm driver 17, And a data collection unit 18.

  The X-ray generator 11 includes an X-ray tube that generates X-rays (for example, a vacuum tube that generates a cone-shaped or pyramid-shaped X-ray beam, not shown). The X-ray generator 11 exposes the generated X-rays to the subject E.

  The X-ray detection unit 12 includes a plurality of X-ray detection elements (not shown). The X-ray detection unit 12 detects X-rays that have passed through the subject E. Specifically, the X-ray detection unit 12 detects X-ray intensity distribution data (hereinafter sometimes referred to as “detection data”) indicating the intensity distribution of X-rays transmitted through the subject E with an X-ray detection element. The detection data is output as a current signal. As the X-ray detection unit 12, for example, a two-dimensional X-ray detector (plane detector) in which a plurality of detection elements are arranged in two directions (slice direction and channel direction) orthogonal to each other is used. The plurality of X-ray detection elements are provided, for example, in 320 rows along the slice direction. By using a multi-row X-ray detector in this way, it is possible to image a three-dimensional imaging region having a width in the slice direction by one rotation scan (volume scan). The slice direction corresponds to the body axis direction of the subject E, and the channel direction corresponds to the rotation direction of the X-ray generation unit 11.

  The rotating body 13 is a member that supports the X-ray generation unit 11 and the X-ray detection unit 12 so as to face each other with the subject E interposed therebetween. The rotating body 13 has an opening 13a penetrating in the slice direction. In the gantry device 10, the rotating body 13 is arranged so as to rotate in a circular orbit around the subject E. That is, the X-ray generation unit 11 and the X-ray detection unit 12 are provided so as to be rotatable along a circular orbit centered on the subject E.

  The high voltage generator 14 applies a high voltage to the X-ray generator 11 (hereinafter, “voltage” means the voltage between the anode and the cathode in the X-ray tube). The X-ray generator 11 generates X-rays based on the high voltage.

  The gantry driving unit 15 drives the rotating body 13 to rotate. The X-ray diaphragm section 16 has a slit (opening) having a predetermined width, and by changing the width of the slit, the fan angle (expansion angle in the channel direction) of X-rays exposed from the X-ray generation section 11 and X Adjust the cone angle of the line (the spread angle in the slice direction). The diaphragm drive unit 17 drives the X-ray diaphragm unit 16 so that the X-rays generated by the X-ray generation unit 11 have a predetermined shape.

  A data collection unit 18 (DAS: Data Acquisition System) collects detection data from the X-ray detection unit 12 (each X-ray detection element). The data collection unit 18 converts the collected detection data (current signal) into a voltage signal, periodically integrates and amplifies the voltage signal, and converts the voltage signal into a digital signal. Then, the data collecting unit 18 transmits the detection data converted into the digital signal to the console device 40. When performing CT fluoroscopy, it is desirable that the reconstruction processing unit 41b (described later) performs reconstruction processing in a short time based on the detection data collected by the data collection unit 18 and obtains a CT image in real time. Therefore, the data collection unit 18 shortens the collection rate of the detection data.

[Bed equipment]
The couch device 30 is a device for placing and moving the subject E to be imaged. The couch device 30 includes a couch 31 and a couch driving unit 32. The couch 31 includes a couch top 33 for placing the subject E and a base 34 that supports the couch top 33. The couch top 33 can be moved by the couch driving unit 32 in the body axis direction of the subject E and in the direction perpendicular to the body axis direction. That is, the bed driving unit 32 can insert and remove the bed top plate 33 on which the subject E is placed with respect to the opening 13 a of the rotating body 13. The base 34 can move the bed top 33 in the vertical direction (a direction perpendicular to the body axis direction of the subject E) by the bed driving unit 32.

[Console device]
The console device 40 is used for operation input to the X-ray CT apparatus 1. The console device 40 has a function of reconstructing CT image data (tomographic image data and volume data) representing the internal form of the subject E from the detection data collected by the gantry device 10. The console device 40 includes a processing unit 41, a setting unit 42, a specifying unit 43, a display control unit 44, a storage unit 45, a display unit 46, a scan control unit 47, and a control unit 48. Has been.

  The processing unit 41 executes various processes on the detection data transmitted from the gantry device 10 (data collection unit 18). The processing unit 41 includes a preprocessing unit 41a, a reconstruction processing unit 41b, and a rendering processing unit 41c.

  The pre-processing unit 41a performs pre-processing such as logarithmic conversion processing, offset correction, sensitivity correction, and beam hardening correction on detection data detected by the gantry device 10 (X-ray detection unit 12) to create projection data. To do.

  The reconstruction processing unit 41b creates CT image data (tomographic image data or three-dimensional volume data) based on the projection data created by the preprocessing unit 41a. For reconstruction of tomographic image data, any method such as a two-dimensional Fourier transform method, a convolution / back projection method, or the like can be employed. Volume data is created by interpolating a plurality of reconstructed tomographic image data. For the reconstruction of volume data, for example, an arbitrary method such as a cone beam reconstruction method, a multi-slice reconstruction method, an enlargement reconstruction method, or the like can be adopted. As described above, a wide range of volume data can be reconstructed by volume scanning using a multi-row X-ray detector. Further, when performing CT fluoroscopy, since the collection rate of the detection data is shortened, the reconstruction time by the reconstruction processing unit 41b is shortened. Therefore, real-time CT image data corresponding to scanning can be created.

  The rendering processing unit 41c performs rendering processing on the three-dimensional volume data created by the reconstruction processing unit 41b, and creates a pseudo three-dimensional image and an MPR image. The “pseudo three-dimensional image” is an image for displaying the three-dimensional structure of the subject E two-dimensionally. The “MPR image” is an image showing a desired cross section of the subject E. Examples of the MPR image include an axial image having a three orthogonal cross section, a sagittal image, a coronal image, and an oblique image having an arbitrary cross section.

  In the present embodiment, the rendering processing unit 41c includes an MPR image creation unit 411c and a cross-sectional image creation unit 412c.

The MPR image creation unit 411c creates an MPR image showing a cross section in a predetermined direction with respect to the volume data. For example, it is assumed that the reconstruction processing unit 41b creates one volume data based on detection data from 320 rows (Z direction) of X-ray detection elements. In this case, the MPR image creation unit 411c can perform rendering processing on the volume data and create a plurality of axial images Ax _k (k = 1 to 320) as MPR images showing a cross section in a predetermined direction. The MPR image creation unit 411c also creates a sagittal image Sg _k (k = 1 to 320) and a coronal image Co _k (k = 1 to 320) as MPR images showing a cross section in a direction different from the predetermined direction. Is possible.

  The cross-sectional image creation unit 412c creates a cross-sectional image (oblique image) of a cross section orthogonal to the cross section and along an arbitrary direction for the MPR image created by the MPR image creation unit 411c. Details of the cross-sectional image creation unit 412c will be described later.

  The setting unit 42 is used to set the insertion path of the puncture needle for the subject E based on the MPR image. The insertion path that is set is a path that indicates how the puncture needle is inserted into the subject E.

As a specific example of the setting unit 42, a case where the insertion path L is set based on the axial image Ax _k (k = 1 to 320) created from the volume data V will be described. 2A and 2B show the axial image Ax _k displayed on the display unit 46. FIG. The axial image Ax _k is an image based on the three-dimensional volume data V. Accordingly, the insertion path L (insertion path position) set based on the axial image Ax _k can be specified by a three-dimensional coordinate value.

First, the surgeon uses an input device (keyboard, mouse, etc.) provided in the X-ray CT apparatus 1 or the like for an arbitrary axial image (here, axial image Ax ₅ ) displayed on the display unit 46. Used to designate the insertion position P of the puncture needle on the body surface (see FIG. 2A).

Next, the surgeon sequentially switches the axial images displayed on the display unit 46 using an input device, and displays an axial image (in this case, an axial image) on which a target site (lesion site or the like) to be biopsied is displayed. Ax ₂₅₀ ). The image is switched by, for example, sliding a slide bar SL (see FIG. 2A and the like) displayed on the display screen of the display unit 46 with an input device.

When the axial image Ax ₂₅₀ on which the target part is displayed can be identified, the operator designates the position S of the target part using the input device (see FIG. 2B). The insertion position P and the position S of the target part are positions in the volume data V. Therefore, the insertion position P and the position S of the target part can be specified by three-dimensional coordinates. The setting unit 42 calculates the shortest distance between the two points, and sets a line segment connecting the shortest distances as the insertion path L (see FIG. 2C. FIG. 2C is a schematic diagram illustrating the insertion path L in the volume data V). Is). The three-dimensional position (coordinate value) of the insertion path L is stored in the storage unit 45.

  Here, an example in which the insertion position P is designated first has been described, but the position S of the target part can also be designated first. That is, the surgeon designates the position S of the target part on the axial image. Then, the surgeon can switch the axial image and specify the insertion position P while confirming the position of the part (for example, blood vessel, bone) where puncture should be avoided. Also in this case, the setting unit 42 sets a line segment connecting the two specified shortest distances as the insertion path L.

  The setting unit 42 performs image processing such as a region growing method on the MPR image, and calculates the position S of the target part. Then, the setting unit 42 calculates the position of the body surface closest to the target site as the insertion position P in the volume data including the MPR image, and sets the line segment connecting the position S and the shortest distance of the insertion position P as the insertion path L. It is also possible to set.

  The setting unit 42 can also set the insertion path L based on a sagittal image, a coronal image, or an oblique image instead of an axial image.

Furthermore, in the above-described specific example, the example in which the insertion path L is set based on a plurality of axial images Ax _k has been described. However, when the puncture needle is inserted from the parallel direction of the cross section, the insertion path L on one MPR image. Can also be set. An MPR image is an image based on volume data. Therefore, even in the case of one MPR image, the setting unit 42 can specify the designated insertion position P and target position S as three-dimensional coordinate values. The setting unit 42 sets a line segment connecting the two specified shortest distances as the insertion path L.

  In the present embodiment, an MPR image (one or a plurality of MPR images) indicating a cross section in a predetermined direction used for setting the insertion path L is a “first MPR image”, and an MPR image indicating a cross section in a direction different from the predetermined direction. (One or a plurality of MPR images) is a “second MPR image”.

The specifying unit 43 specifies an image region corresponding to the insertion path in the MPR image (first MPR image and second MPR image). Here, an example will be described in which an image region corresponding to the insertion path L is specified for one axial image Ax, sagittal image Sg, and coronal image Co. FIG. 3 shows an example of the display screen of the display unit 46. The axial image Ax is displayed on the display screen 46a. The sagittal image Sg is displayed on the display screen 46b. The coronal image Co is displayed on the display screen 46c. It is assumed that the axial image Ax, the sagittal image Sg, the coronal image Co, and the axial image Ax _k used when setting the insertion path L are MPR images based on the same volume data. That is, the axial image Ax here corresponds to one of the axial images Ax _k .

As described above, the insertion path can be specified by a three-dimensional coordinate value. Accordingly, the specifying unit 43 specifies the positions on the image corresponding to the coordinate values of the insertion path L as the image regions L _Ax , L _Sg , and L _Co in the axial image Ax, the sagittal image Sg, and the coronal image Co, respectively. The display control unit 44 superimposes the specified image area on each image (see FIG. 3).

Here, the image region L _Ax identified in axial images Ax shows only XY direction position of the set insertion path L (coordinate value). Similarly, the image area L _Sg specified by the sagittal image Sg shows only the position (coordinate value) of the set insertion path L in the XZ direction. The image area L _Co specified by the coronal image Co shows only the position (coordinate value) in the YZ direction of the set insertion path L. That is, the image area displayed on each MPR image shows the set insertion path L in a pseudo manner.

Therefore, the cross-sectional image creation unit 412c performs the MPR for each of the axial image Ax in which the image region L _Ax is specified, the sagittal image Sg in which the image region L _Sg is specified, and the coronal image Co in which the image region L _Co is specified. A cross-sectional image of a cross section orthogonal to the cross section of the image and along the image region is created.

Specifically, the cross-sectional image creation unit 412c creates the cross-sectional image O _Ax by rendering the volume data in the direction of the cross section orthogonal to the axial image _Ax and along the image area LAx on the axial image Ax. To do. Similarly, cross-sectional image creation unit 412c is orthogonal to the sagittal image Sg, and volume data in the direction of the cross section along the image area L _Sg on sagittal image Sg By rendering, and creates a cross-sectional image O _Sg. Further, the cross-sectional image creation unit 412c creates the cross-sectional image O _Co by rendering the volume data in the direction of the cross-section orthogonal to the coronal image _Co and along the image region L _Co on the coronal image Co. The created cross-sectional image is an image including the set insertion path L. The created cross-sectional image and the position (three-dimensional coordinate value) of the cross-sectional image are stored in the storage unit 45.

  For example, when the insertion path L is set on one axial image, the image area in the axial image specified by the specifying unit 43 indicates the insertion path L itself. That is, the axial image is displayed as an image including the insertion path L. Therefore, the cross-sectional image creation unit 412c does not have to create a cross-sectional image for the axial image.

  The display control unit 44 performs various controls related to image display. For example, the display control unit 44 performs control to display the MPR image or the like created by the rendering processing unit 41c on the display unit 46 (see FIGS. 3 and 4).

  Further, in the present embodiment, the display control unit 44 provides the display unit 46 with a plurality of cross-sectional images created by the cross-sectional image creation unit 412c in response to a surgeon's request (based on input from an input device or the like). Switch to display. FIG. 4 is a schematic diagram illustrating an example in which cross-sectional images are switched and displayed on the display unit 46 (display screen 46d).

As described above, it is assumed that the cross-sectional image O _Ax , the cross-sectional image O _Sg , and the cross-sectional image O _Co are generated by the cross-sectional image generating unit 412c. In this case, the display control unit 44 sequentially switches and displays the cross-sectional image O _Ax , the cross-sectional image O _Sg , and the cross-sectional image O _Co on the display screen 46 d of the display unit 46 (see FIG. 4). For example, the display screen 46d (or an icon or the like displayed on the display unit 46) is clicked with a mouse which is an example of an input device. The display control unit 44 sequentially switches and displays the cross-sectional images based on the input signal.

  These cross-sectional images are cross-sectional images including the set insertion path L. Therefore, the surgeon can confirm the insertion path L in various cross sections (in various directions) by referring to those cross-sectional images. That is, the X-ray CT apparatus 1 in the present embodiment can display the set insertion path L in an easy-to-understand manner for the operator.

Here, an example of switching in the order of the cross-sectional image O _Ax , the cross-sectional image O _Sg , and the cross-sectional image O _Co has been described, but the order of switching the cross-sectional images can be arbitrarily set. Alternatively, the switching may not be sequential. For example, when switching is set in the order of the cross-sectional image O _Ax , the cross-sectional image O _Sg , and the cross-sectional image O _Co , the cross-sectional image O _Ax is confirmed again after the cross-sectional image O _Sg is displayed. There is. In this case, for example, a “Back space” key of a keyboard which is an example of an input device is pressed. The display control unit 44 displays the cross-sectional image O _Ax again based on the input signal from the keyboard.

  In the present embodiment, switching of the cross-sectional image has been described. However, the display of the cross-sectional image and the MPR image can be arbitrarily set. For example, the display control unit 44 can switch between the MPR image and the cross-sectional image based on the input signal from the input device, and can display only one of the types (MPR image or cross-sectional image) on the display unit 46. It is.

  The storage unit 45 is configured by a semiconductor storage device such as a RAM or a ROM. In addition to the position of the insertion path, the storage unit 45 stores detection data, projection data, or CT image data after reconstruction processing.

  The display unit 46 includes an arbitrary display device such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube) display. For example, the display unit 46 displays an MPR image obtained by rendering volume data.

  The scan control unit 47 controls various operations related to X-ray scanning. For example, the scan control unit 47 controls the high voltage generation unit 14 to apply a high voltage to the X-ray generation unit 11. The scan control unit 47 controls the gantry driving unit 15 to rotationally drive the rotating body 13. The scan control unit 47 controls the aperture driving unit 17 to operate the X-ray aperture unit 16. The scan control unit 47 controls the bed driving unit 32 to move the bed 31.

  The control unit 48 performs overall control of the X-ray CT apparatus 1 by controlling operations of the gantry device 10, the couch device 30, and the console device 40. For example, the control unit 48 controls the scan control unit 47 to cause the gantry device 10 to perform a preliminary scan and a main scan and collect detection data. Further, the control unit 48 controls the processing unit 41 to perform various types of processing (preprocessing, reconstruction processing, etc.) on the detected data. Alternatively, the control unit 48 controls the display control unit 44 to display an image based on the CT image data stored in the storage unit 45 on the display unit 46.

<Operation>
Next, the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, an operation in the case of creating an insertion path plan before performing a biopsy using CT fluoroscopy will be described.

  Before starting the biopsy, first, the X-ray CT apparatus 1 performs an X-ray scan (preliminary scan) on the subject E to create volume data V.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E, and acquires the detection data (S10). Detection data detected by the X-ray detection unit 12 is collected by the data collection unit 18 and sent to the processing unit 41 (pre-processing unit 41a).

  The pre-processing unit 41a performs pre-processing such as logarithmic conversion processing, offset correction, sensitivity correction, and beam hardening correction on the detection data acquired in S10, and creates projection data (S11). The created projection data is sent to the reconstruction processing unit 41b based on the control of the control unit 48.

  The reconstruction processing unit 41b creates a plurality of tomographic image data based on the projection data created in S11. The reconstruction processing unit 41b creates volume data V by performing interpolation processing on a plurality of tomographic image data (S12).

  The MPR image creation unit 411c renders the volume data V created in S12 to create an MPR image (axial image, sagittal image, coronal image) (S13).

  Based on the axial image created in S13, the setting unit 42 sets the insertion path L (S14).

Based on the insertion path L set in S <b> 14, the specifying unit 43 performs image regions corresponding to the insertion path L (image areas L _Ax , L _Sg , L in each of the arbitrary axial image Ax, sagittal image Sg, and coronal image Co). _Co ) is specified (S15). The display control unit 44 superimposes the image region L _Ax specified in S15 on the axial image Ax. The display control unit 44 superimposes the image region L _Sg specified in S15 on the sagittal image Sg. The display control unit 44 superimposes the image region L _Co specified in S15 on the coronal image Co. The display control unit 44 causes the display unit 46 to display the axial image Ax, the sagittal image Sg, and the coronal image Co on which the image regions are superimposed (see FIG. 4).

The cross-sectional image creation unit 412c creates a cross-sectional image (cross-sectional images O _Ax , O _Sg , O _Co ) that is orthogonal to the cross-section of the MPR image whose image area is specified in S15 and is along the specified image area. (S16).

  The display control unit 44 displays any one of the cross-sectional images created in S16 on the display screen 46d of the display unit 46. The display control unit 44 receives an instruction input from an input device or the like, and switches and displays the cross-sectional images (S17, see FIG. 4).

  The processing unit 41, the setting unit 42, the specifying unit 43, the display control unit 44, the scan control unit 47, and the control unit 48 are, for example, a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), or an ASIC (Application Specific). A processing device (not shown) such as an integrated circuit (ROM) and a storage device (not shown) such as a ROM (Read Only Memory), a RAM (Random Access Memory), or an HDD (Hard Disc Drive) may be used. The storage device stores a processing program for executing the function of the processing unit 41. The storage device also stores a setting unit processing program for executing the function of the setting unit 42. In addition, the storage unit stores a specific unit processing program for executing the function of the specific unit 43. Further, the storage device stores a display control program for executing the function of the display control unit 44. Further, the storage device stores a scan control program for executing the function of the scan control unit 47. The storage device stores a control program for executing the function of the control unit 48. A processing device such as a CPU executes the functions of each unit by executing each program stored in the storage device.

<Action and effect>
The operation and effect of this embodiment will be described.

The X-ray CT apparatus 1 of the present embodiment creates volume data based on the result of scanning the subject E with X-rays. The X-ray CT apparatus 1 includes an MPR image creation unit 411c, a setting unit 42, a specifying unit 43, a cross-sectional image creation unit 412c, and a display control unit 44. The MPR image creation unit 411c creates a first MPR image (axial image Ax) showing a cross section in a predetermined direction with respect to volume data and a second MPR image (sagittal image Sg, coronal image Co) showing a cross section in a direction different from the predetermined direction. . The setting unit 42 is used to set the insertion path of the puncture needle with respect to the subject E based on the first MPR image. The specifying unit 43 specifies an image region (image region L _Ax , image region L _Sg , image region L _Co ) corresponding to the insertion path in each of the first MPR image and the second MPR image. For each of the first MPR image and the second MPR image in which the image region is specified, the cross-sectional image creation unit 412c is a cross-sectional image (cross-sectional image O _Ax , cross-sectional image) orthogonal to the cross-section of the MPR image and along the image region. O _Sg and cross-sectional image O _Co ) are created. The display control unit 44 causes the display unit 46 to switch and display the cross-sectional image.

  As described above, the specifying unit 43 specifies an image region based on the set insertion path. For each of the first MPR image and the second MPR image in which the image region is specified, the cross-sectional image creation unit 412c creates a cross-sectional image that is orthogonal to the cross-section of the MPR image and is along the image region. The display control unit 44 causes the display unit 46 to switch and display the cross-sectional image. The cross-sectional image is a cross-sectional image including the set insertion path. Therefore, the surgeon can confirm the insertion path from various directions (cross sections) by referring to the cross-sectional images. That is, according to the X-ray CT apparatus 1 in the present embodiment, it is possible to display an image that allows easy confirmation of the insertion path of the puncture needle.

(Second Embodiment)
The configuration of the X-ray CT apparatus 1 according to the second embodiment will be described with reference to FIGS. In the present embodiment, a configuration will be described in which a graphic is displayed on the display unit 46 and the cross-sectional position of the cross-sectional image is switched to the graphic and displayed in accordance with the switching of the cross-sectional image. Detailed description of the same configuration as that of the first embodiment will be omitted.

  As shown in FIG. 6, the X-ray CT apparatus 1 according to the present embodiment has a creation unit 49.

  The creation unit 49 creates a cuboid figure (hereinafter also referred to as a “viewing box”) that represents volume data in a simulated manner. Note that since the pseudo three-dimensional image of the viewing box created by the creation unit 49 and the viewing box displayed on the display unit 46 by the display control unit 44 have a one-to-one correspondence, they are the same in this embodiment. You may see.

  As a specific example of the creation unit 49, a case where the viewing box B is created based on the volume data V will be described. Here, the volume data V is shown as a cube that is a rectangular parallelepiped having the same length of each side. Further, it is assumed that the viewing box B and the volume data V are in the same coordinate system. First, the creation unit 49 extracts the contour portion R of the volume data V by a method such as edge detection (see FIG. 7A). Next, the creating unit 49 creates the viewing box B by converting the extracted contour portion R at a predetermined scale (see FIG. 7B). The scale is a value set in advance based on, for example, the display area of the viewing box B on the display unit 46.

  In the present embodiment, the creation unit 49 creates the viewing box B so that the scales of the sides of the volume data V are the same. For example, a case where the scale is set to 1/10 will be described. As shown in FIG. 7A, when the length of one side of the volume data V (contour portion R) is 100 mm, the creation unit 49 displays a cube-shaped viewing with a side length of 10 mm based on the scale 1/10. Box B is created (see FIG. 7B).

  The display control unit 44 causes the display unit 46 to display a graphic (viewing box B). Specifically, the display control unit 44 displays the viewing box B created by the creation unit 49 on the display unit 46 as a pseudo three-dimensional image. In the present embodiment, the display control unit 44 displays the viewing boxes Ba to Bd on the display screens 46a to 46d (see FIG. 8). The viewing boxes Ba to Bd are created based on the same volume data (volume data V).

  The display control unit 44 causes the viewing box to display the cross-sectional position of the image displayed on the display unit 46 (which cross-section of the volume data corresponds to the displayed image).

For example, the display control unit 44 converts the position (coordinate value) of the cross-sectional image O _Ax stored in the storage unit 45 at the same scale as the scale used when creating the viewing box Bd. Then, the display control unit 44 specifies the position in the viewing box Bd corresponding to the converted value as the cross-sectional position O _Ax ′. The display control unit 44 displays the cross-sectional position O _Ax ′ in the viewing box Bd (see FIG. 8). By the same method, the display control unit 44 displays the cross-sectional position Ax ′ corresponding to the axial image Ax on the viewing box Ba. In addition, the display control unit 44 displays the cross-sectional position Sg ′ corresponding to the sagittal image Sg on the viewing box Bb. In addition, the display control unit 44 displays the cross-sectional position Co ′ corresponding to the coronal image Co in the viewing box Bc.

In the present embodiment, the display control unit 44 creates a viewing box for each position (coordinate value) of the cross-sectional image O _Sg and the cross-sectional image O _Co stored in the storage unit 45 by the same method as described above. Convert at the same scale as. Then, the display control unit 44 specifies the position in the viewing box corresponding to the converted value as the cross-sectional position O _Sg ′ and the cross-sectional position O _Co ′. The identified cross-sectional position is stored in the storage unit 45.

  The viewing boxes Ba to Bd and the volume data V are in the same coordinate system. Therefore, the cross-sectional position displayed in the viewing boxes Ba to Bd and the position of the image in the volume data V have a correspondence relationship. That is, the surgeon can easily grasp the position of the displayed image by referring to the viewing box displayed on the display unit 46.

Furthermore, in the present embodiment, the display control unit 44 switches the cross-sectional position of the cross-sectional image to the viewing box Bd and displays it in accordance with the switching of the cross-sectional image displayed on the display unit 46. FIG. 9 is a schematic diagram illustrating an example in which the cross-sectional position of the cross-sectional image is switched and displayed in the viewing box Bd displayed on the display unit 46 (display screen 46d). Here, it is assumed that the cross-sectional image O _Ax is displayed on the display screen 46d. The order of switching the cross-sectional images is assumed to be “cross-sectional image O _Ax → cross-sectional image O _Sg → cross-sectional image O _Co → cross-sectional image O _Ax ...

For example, the viewing box Bd is clicked with a mouse which is an example of an input device. Based on the input signal, the display control unit 44 reads the cross-sectional image O _Sg from the storage unit 45 and causes the display unit 46 to display the cross-sectional image O _{Ax instead} of the cross-sectional image O _Ax . At this time, the display control unit 44 reads the cross-sectional position O _Sg ′ corresponding to the displayed cross-sectional image O _Sg from the storage unit 45 and displays it on the viewing box Bd.

  Note that the display control unit 44 can also display the cross-sectional position corresponding to the cross-sectional image and the cross-sectional position of the MPR image that is the basis of the cross-sectional image in the viewing box.

<Operation>
Next, the operation of the X-ray CT apparatus 1 according to the present embodiment will be described with reference to FIG. Here, an operation in the case of creating an insertion path plan before performing a biopsy using CT fluoroscopy will be described.

  Before starting the biopsy, first, the X-ray CT apparatus 1 performs an X-ray scan (preliminary scan) on the subject E to create volume data V.

  Specifically, the X-ray generation unit 11 emits X-rays to the subject E. The X-ray detection unit 12 detects X-rays that have passed through the subject E and acquires the detection data (S20).

  The pre-processing unit 41a performs pre-processing such as logarithmic conversion processing, offset correction, sensitivity correction, and beam hardening correction on the detection data acquired in S20 to create projection data (S21).

  The reconstruction processing unit 41b creates a plurality of tomographic image data based on the projection data created in S21. The reconstruction processing unit 41b creates volume data V by performing interpolation processing on a plurality of tomographic image data (S22).

  The MPR image creation unit 411c creates an MPR image (axial image, sagittal image, coronal image) by rendering the volume data V created in S22 (S23).

  Based on the axial image created in S23, the setting unit 42 sets the insertion path L (S24).

Based on the insertion path L set in S24, the specifying unit 43 determines the image area (image area L _Ax , L _Sg , L) corresponding to the insertion path L in each of the arbitrary axial image Ax, sagittal image Sg, and coronal image Co. _Co ) is specified (S25).

The cross-sectional image creation unit 412c creates a cross-sectional image (cross-sectional images O _Ax , O _Sg , O _Co ) that is orthogonal to the cross-section of the MPR image whose image area is specified in S25 and is along the specified image area. (S26).

  The creation unit 49 creates viewing boxes (viewing boxes Ba to Bd) based on the volume data V created in S22 (S27).

The display control unit 44 displays the cross-sectional image (for example, the cross-sectional image O _Ax ) created in S26 on the display screen 46d of the display unit 46. Further, the display control unit 44 displays the cross-sectional position corresponding to the displayed cross-sectional image in the viewing box Bd (S28). For example, the display control unit 44 displays the cross-sectional position O _Ax ′ corresponding to the cross-sectional image O _Ax in the viewing box Bd.

The display control unit 44 receives an instruction input from an input device or the like, and switches and displays the cross-sectional images (S29). For example, the display control unit 44 switches the cross-sectional image O _Ax to the cross-sectional image O _Sg and displays it.

The display control unit 44 switches the cross-sectional position in the viewing box Bd to the corresponding cross-sectional position for display in accordance with the switching of the cross-sectional image (S30). For example, the display control unit 44 switches from the cross-sectional position O _Ax ′ to the cross-sectional position O _Sg ′ and displays it.

<Action and effect>
The operation and effect of this embodiment will be described.

  The display control unit 44 in the X-ray CT apparatus 1 of the present embodiment displays a rectangular parallelepiped figure (viewing box) representing the volume data in a simulated manner on the display unit 46, and according to switching of the cross-sectional image, The cross-sectional position of the cross-sectional image is switched to a graphic and displayed.

  In this way, by displaying the cross-sectional position of the cross-sectional image in the viewing box and switching the cross-sectional position in accordance with the switching of the cross-sectional image, it is possible to determine which direction in the volume data the cross-sectional image currently displayed is. Can be easily grasped. That is, according to the X-ray CT apparatus 1 of the present embodiment, an image that allows easy confirmation of the insertion path of the puncture needle can be displayed, and the cross-sectional position of the image can be easily grasped.

(Modification 1)
The display control unit 44 can also display the cross-sectional image and the MPR image that is the basis of the cross-sectional image in association with each other. In this case, it is possible to easily grasp the correspondence between the cross-sectional image and the MPR image that is the origin of the cross-sectional image.

For example, when the cross-sectional image _OAx is displayed on the display screen 46d, the display control unit 44 displays the frame (or display area) of the display screen 46a and the frame (or display area) of the display screen 46d in the same color. (See FIG. 11. In FIG. 11, the frame of the display screen 46a and the frame of the display screen 46d that are displayed in the same color are indicated by bold lines).

Alternatively, the display control unit 44 causes the display unit 46 to display a viewing box, and at least a part of a display area in which the cross-sectional position of the cross-sectional image in the viewing box and the MPR image that is the basis of the cross-sectional image are displayed. Can be displayed in the same color. For example, the cross-sectional position O _Ax ′ in the viewing box Bd and the frame of the display screen 46a on which the axial image Ax is displayed can be displayed in the same color.

Conversely, the display control unit 44 displays the viewing box on the display unit 46, and at least a part of the display area in which the cross-sectional image is displayed and the MPR that is the basis of the cross-sectional image displayed in the viewing box. It is also possible to display the cross-sectional position of the image in the same color. For example, it is possible to display a frame of the display screen 46d of cross-sectional images O _Ax based on the axial image Ax is displayed, and a cross-sectional position Ax' of axial images Ax in viewing box Ba in the same color.

(Modification 2)
The storage unit 45 stores the cross-sectional position (coordinate value) of the created cross-sectional image. Then, for the volume data obtained at different timings, the cross-sectional image creation unit 412c can create a cross-sectional image based on the stored cross-sectional position. That is, the cross-sectional image creation unit 412c can always create a cross-sectional image at the same cross-sectional position in each volume data obtained at different timings. In this case, the volume data is assumed to have the same number of pieces of tomographic image data and the number of pixels of the image. Further, it is assumed that the photographing conditions (photographing position, rotation speed of the rotating body 13 and the like) are equal. That is, it is assumed that the volume data is in the same coordinate system.

  Here, for example, when the puncture needle does not advance along the insertion path L set based on certain volume data (MPR image based on volume data), a cross-sectional image based on volume data obtained at different timings is used. The puncture needle is not displayed. Therefore, according to the configuration of this modification, the operator can easily grasp the puncture needle displacement (deviation from the planned route).

<Effects common to the embodiments>
According to the X-ray CT apparatus of at least one embodiment described above, the cross-sectional image can be switched and displayed on the display unit. Therefore, the surgeon can confirm the insertion path from various directions (cross sections) by referring to the cross-sectional images. That is, according to the X-ray CT apparatus of the embodiment, it is possible to display an image that allows easy confirmation of the insertion path of the puncture needle.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 X-ray CT apparatus 10 Base apparatus 11 X-ray generation part 12 X-ray detection part 13 Rotating body 13a Opening part 14 High voltage generation part 15 Base drive part 16 X-ray aperture part 17 Aperture drive part 18 Data collection part 30 Bed apparatus 32 Bed drive unit 33 Bed top plate 34 Base 40 Console device 41 Processing unit 41a Preprocessing unit 41b Reconstruction processing unit 41c Rendering processing unit 411c MPR image creation unit 412c Cross-sectional image creation unit 42 Setting unit 43 Identification unit 44 Display control unit 45 Storage unit 46 Display unit 47 Scan control unit 48 Control unit E Subject

Claims (8)

An X-ray CT apparatus for creating volume data based on a result of scanning a subject with X-rays,
An MPR image creating unit for creating a first MPR image showing a cross section in a predetermined direction with respect to the volume data and a second MPR image showing a cross section in a direction different from the predetermined direction;
A setting unit for setting an insertion path of a puncture needle to the subject based on the first MPR image;
A specifying unit that specifies an image region corresponding to the insertion path in each of the first MPR image and the second MPR image;
For each of the first MPR image and the second MPR image in which the image region is specified, a cross-sectional image creation unit that creates a cross-sectional image of a cross-section perpendicular to the cross-section of the MPR image and along the image region;
A display control unit for switching and displaying the cross-sectional image on the display unit;
An X-ray CT apparatus comprising:   The X-ray CT apparatus according to claim 1, wherein the display control unit causes the display unit to display the first MPR image and the second MPR image on which the identified image region is superimposed.   The display control unit displays a rectangular parallelepiped figure representing volume data in a simulated manner on the display unit, and switches the cross-sectional position of the cross-sectional image to the graphic in accordance with switching of the cross-sectional image. The X-ray CT apparatus according to claim 1 or 2.   The X-ray CT apparatus according to claim 1, wherein the display control unit displays the cross-sectional image and the MPR image that is the basis of the cross-sectional image in association with each other.   The display control unit displays a rectangular parallelepiped graphic representing volume data in a simulated manner on the display unit, and displays the cross-sectional position of the cross-sectional image in the graphic and the MPR image from which the cross-sectional image is based. 5. The X-ray CT apparatus according to claim 4, wherein at least a part of the display area is displayed in the same color.   The display control unit displays a rectangular parallelepiped graphic representing volume data on the display unit, and displays at least a part of a display area where the cross-sectional image is displayed and the cross-sectional image displayed on the graphic. The X-ray CT apparatus according to claim 4, wherein the cross-sectional position of the original MPR image is displayed in the same color.   The MPR image creation unit creates any one of an axial image, a sagittal image, a coronal image, and an oblique image of the subject as the first MPR image. The X-ray CT apparatus described.   The X-ray CT apparatus according to claim 1, wherein the first MPR image used in the setting unit includes a plurality of images.

Images