JP2008161643A - X-ray imaging apparatus and three-dimensional road map positioning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily perform the positioning of a transparent image and a mask image on a 3D road map. <P>SOLUTION: The display control part 50 of a 3D road map automatically sets SID, FOV, the bed height and the arm angle during collecting the mask image for the start of the 3D road map. Specifically, the set condition identifying part 52 identifies SID, FOV, the bed height, and the arm angle during collecting images from 3D-DSA image information nearby 0 degree of the main rotation among 3D-DSA images as a reconstruction resource of the mask image, and the setting part 53 automatically sets SID, FOV, the bed height, and the arm angle identified by the set condition identifying part 52. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a three-dimensional road map in an X-ray imaging apparatus, and more particularly to a method for aligning a three-dimensional road map.

  When inserting a wire into a patient's blood vessel for the purpose of treating the blood vessel, there is a 3D (three-dimensional) road map technology as a technology for assisting the insertion of the wire. The 3D roadmap technology displays a 3D image of a blood vessel such as a 3D volume rendering (hereinafter referred to as “3D-VR”) of a blood vessel as a mask image on a fluoroscopic image in an X-ray imaging apparatus such as digital fluorography. This is a technique for guiding the insertion of the wire.

  In order to superimpose the 3D mask image on the fluoroscopic image by this 3D road map, accurate alignment of the fluoroscopic image and the 3D mask image is required. FIG. 9 is an explanatory diagram for explaining alignment between a fluoroscopic image and a 3D mask image. In the figure, it is necessary to match the geometric position of the perspective image and the geometric position of the 3D mask image so that the blood vessels of the left perspective image and the right 3D mask image overlap.

  Conventionally, since it is difficult to accurately align the fluoroscopic image and the 3D mask image, the 3D road map is performed by using the 3D image data collected immediately before the 3D road map to make the alignment unnecessary. It was. Alternatively, as another method, as shown in FIG. 10, positioning is performed from the blood vessel running of the 3D-VR mask image and the shape of the wire of the fluoroscopic image (see, for example, Patent Document 1).

JP 2000-116789 A

  However, the method of using the 3D image data collected immediately before the 3D road map has a problem that the patient moves during the 3D mask image creation process, thereby causing a positional shift. In addition, in this method, it is necessary to perform 3D-DSA for creating a 3D-VR mask image before the procedure, and there is a problem that patient exposure and use of a contrast medium increase. Here, 3D-DSA refers to obtaining a plurality of DSA images by irradiating X-rays while rotating around a patient, and the DSA image refers to an X-ray image (contrast image) collected with a contrast agent. ) Is a blood vessel image (subtraction image) obtained by drawing an X-ray image collected without adding a contrast medium.

  Further, in the method of performing alignment based on the blood vessel running of the 3D-VR mask image and the shape of the wire of the fluoroscopic image, it is necessary to advance the wire to a part where the position can be determined to some extent before the 3D road map. The map is to bring the wire to the target vessel, and if the wire has to be advanced before the roadmap, the wire operation before the roadmap is still difficult. There's a problem.

  The present invention has been made to solve the above-described problems caused by the prior art, and an X-ray imaging apparatus and a three-dimensional load capable of easily aligning a fluoroscopic image and a 3D mask image in a 3D road map. An object is to provide a map alignment method.

  In order to solve the above-described problems and achieve the object, the present invention according to claim 1 is an X-ray imaging apparatus having a three-dimensional road map function, which is an image used as a mask image of a three-dimensional road map. It is characterized by comprising setting condition specifying means for specifying the setting conditions of the apparatus when data is collected, and condition setting means for setting the apparatus to the setting conditions specified by the setting condition specifying means.

  According to a seventh aspect of the present invention, there is provided a method for aligning a three-dimensional road map by an X-ray imaging apparatus having a three-dimensional road map function, wherein image data of an image used as a mask image of the three-dimensional road map is collected. A setting condition specifying step for specifying the setting condition of the device when it is set, and a condition setting step for setting the device to the setting condition specified by the setting condition specifying step.

  According to the first or seventh aspect of the present invention, the alignment of the three-dimensional road map can be facilitated.

  Exemplary embodiments of an X-ray imaging apparatus and a three-dimensional road map alignment method according to the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the case where the present invention is applied to a digital fluorography apparatus will be mainly described.

  First, the 3D road map alignment method according to the present embodiment will be described. FIG. 1 is an explanatory diagram for explaining a 3D road map alignment method according to the present embodiment. As shown in the figure, in this 3D road map alignment, when the operator selects a 3D road map mask image (hereinafter referred to as “mask image”) (step SA1), the digital fluorography apparatus according to the present embodiment is selected. Retrieves the 3D-DSA unsub image that is the reconstruction source of the mask image (step SA2), and selects an unsub image whose main rotation is around 0 degrees from the retrieved unsub image (step SA3). Here, the unsub-image is an X-ray image, that is, a mask image collected without adding a contrast agent.

  The digital fluorography apparatus according to the present embodiment uses the X-ray tube focal point-X-ray detector distance (SID), the image field size (FOV), the bed height, and the arm angle when the selected unsub image is collected. And the negative / positive of the selected unsub-image is reversed (step SA4). In addition to the SID, FOV, bed height, and arm angle, the tube voltage can be set.

  Then, the digital fluorography apparatus according to the present embodiment uses the image obtained by inverting the negative / positive as a mask image (step SA5) and superimposes it on the fluoroscopic image (step SA6). Then, the operator performs panning using the superimposed mask images as subtraction and performs horizontal alignment, thereby aligning the 3D road map (step SA7). Here, panning is to move the position of viewing as an image by moving the top of the bed during fluoroscopy / photographing.

  As described above, in the 3D road map alignment according to the present embodiment, the digital fluorography apparatus is automatically set to the setting conditions when the 3D-DSA unsub image corresponding to the mask image selected by the operator is acquired. The operator can easily align the mask image and the fluoroscopic image.

  Next, the configuration of the digital fluorography apparatus according to this embodiment will be described. FIG. 2 is a functional block diagram illustrating the configuration of the digital fluorography apparatus according to the present embodiment. As shown in the figure, the digital fluorography apparatus 100 detects image data by detecting an X-ray generator 1 that generates X-rays to be irradiated to a patient 45 on a bed 17 and X-rays transmitted through the patient 45. The X-ray detection unit 2 to be generated, the holding unit 5 that holds the X-ray generation unit 1 and the flat detector 21, the mechanism unit 3 that moves the bed 17, and the X-ray generation unit 1 are necessary for generating X-rays. A high voltage generator 4 that supplies a high voltage, a mechanism controller 6 that controls the mechanism 3, and an image data generated based on the X-rays detected by the X-ray detector 2 and the image data An image calculation / storage unit 7, a display unit 8 for displaying an image, an operation unit 9 for receiving an operation by an operator, and a system control unit 10 for controlling the entire digital fluorography apparatus 100.

  The X-ray generation unit 1 irradiates the X-ray tube 15 that generates X-rays using the high voltage supplied from the high-voltage generation unit 4 and shields a part of the X-rays generated by the X-ray tube 15. And an X-ray restrictor 16 for controlling the field.

  The X-ray detection unit 2 converts the X-ray transmitted through the patient 45 into electric charges and detects them, a gate driver 22 that extracts electric charges from the flat detectors 21, and electric charges detected by the flat detectors 21. And an image data generation unit 11 for generating image data from the image data. The image data generation unit 11 includes a charge / voltage converter 23 that converts the charge detected by the flat detector 21 into a voltage, and an A / D converter that converts the voltage converted by the charge / voltage converter 23 into a digital value. 24 and a parallel / serial converter 25 for converting the parallel output of the A / D converter 24 into a serial output.

  The mechanism unit 3 includes a holding arm moving mechanism 41 that moves the holding arm 5 based on an instruction from the mechanism control unit 6, and a bed moving mechanism 42 that moves the bed 17 based on an instruction from the mechanism control unit 6. The image calculation / storage unit 7 includes an image calculation circuit 12 that performs reconstruction calculation and subtraction calculation on the image data generated by the image data generation unit 11, and an image data storage circuit 13 that stores the image data.

  The display unit 8 includes a display image memory 31 that holds display image data, a D / A converter 32 that converts image data in the display image memory 31 into an analog signal, and an output of the D / A converter 32. A display circuit 33 that performs a corresponding display on the monitor 34 and a monitor 34 are provided.

  FIG. 3 is a diagram illustrating a configuration example of the display unit 8 and the operation unit 9. As shown in the figure, in this configuration example, the monitor 34 outputs a fluoroscopic monitor that displays a fluoroscopic image, a reference monitor that displays a 3D-VR image such as a collected image or mask image, and the digital fluorography apparatus 100 outputs. It consists of a system monitor that displays messages. The operation unit 9 includes a main console provided with operation buttons, a keyboard used for character input, and a mouse used for instructions from a monitor screen. Here, the 3D road map image is displayed on the fluoroscopic monitor, but may be displayed on the reference monitor.

  The system control unit 10 includes a 3D road map display control unit 50 that controls display of the 3D road map. FIG. 4 is a functional block diagram illustrating a configuration of the 3D road map display control unit 50. As shown in the figure, the 3D road map display control unit 50 includes an operation receiving unit 51, a setting condition specifying unit 52, a setting unit 53, a subtraction processing unit 54, and a 3D road map processing unit 55. . The 3D road map display control unit 50 is implemented as software that operates on a CPU included in the system control unit 10.

  The operation accepting unit 51 is a processing unit that receives information related to the operation of the operator from the operation unit 9 and distributes the information to a functional unit that performs processing corresponding to the operation. For example, when the mask image is specified by the operator, the operation receiving unit 51 notifies the setting condition specifying unit 52 that the mask image has been specified. When the operator specifies the 3D roadmap start, The 3D roadmap processing unit 55 is notified that the 3D roadmap start has been designated.

  The setting condition specifying unit 52 is a processing unit that specifies setting conditions when a mask image is captured. Specifically, the setting condition specifying unit 52 is specified when the operation receiving unit 51 is notified that a mask image has been specified. SID, FOV, bed height and arm when the 3D-DSA which is the reconstruction source of the mask image is selected, the unsub image whose main rotation is around 0 degrees is extracted from the unsub image, and the unsub image is collected Identify the angle.

  The setting unit 53 is a processing unit that sets the digital fluorography apparatus 100 to the SID, FOV, bed height, and arm angle specified by the setting condition specifying unit 52.

  As described above, the setting condition specifying unit 52 specifies the setting condition when the mask image is captured from the unsub image corresponding to the mask image, and the setting condition when the setting unit 53 captures the mask image is set as the digital fluorography apparatus 100. By aligning, it is possible to facilitate alignment during 3D roadmap.

  In addition, the setting unit 53 receives information on the alignment performed by the operator for the subtraction displayed by the subtraction processing unit 54 via the operation receiving unit 51 and instructs the mechanism control unit 6 to move the bed. To do.

  The subtraction processing unit 54 is a processing unit that inverts the negative / positive of the unsub image extracted by the setting condition specifying unit 52 and displays the subtraction using the inverted image as a mask image.

  The 3D road map processing unit 55 is a processing unit that performs 3D road map display when notified from the operation receiving unit 51 that a 3D road map start is designated.

  Next, a processing procedure of 3D road map display control processing by the 3D road map display control unit 50 will be described with reference to FIGS. FIG. 5 is a flowchart showing a processing procedure of 3D road map display control processing by the 3D road map display control unit 50. As shown in the figure, in this 3D road map display control process, the 3D road map display control unit 50 receives a designation of a 3D-VR image as a mask image from the operator by the operation receiving unit 51, and a setting condition specifying unit. 52 is notified (step S1).

  Then, the setting condition specifying unit 52 searches the image calculation / storage unit 7 to select the original 3D-DSA unsub image of the mask image (step S2), and RAO / CRA = 0 degrees from the selected 3D-DSA unsub image. An image near / 0 degrees, that is, an image near the main rotation angle of 0 degrees is selected (step S3). FIG. 6A shows the procedure of steps S1 to S3 together with related images.

  Then, the setting condition specifying unit 52 specifies the SID, FOV, bed height, and arm angle at the time of image collection from the image information selected in step S3, and the setting unit 53 specifies the SID specified by the setting condition specifying unit 52, FOV, bed height and arm angle are set (step S4).

  FIG. 6B shows the procedure of steps S3 to S4 together with related images. FIG. 7 shows a setting example of SID, FOV, bed height, and arm angle. In the example of FIG. 7, before the 3D roadmap, the settings of SID “short”, FOV “enlarged”, bed height “low eye”, and arm angle “tilted” In order to perform alignment, the SID, FOV, bed height, and arm angle are changed to the settings when the 3D-DSA unsub-image with the main rotation of the arm near 0 degrees is acquired.

  Then, the subtraction processing unit 54 inverts the negative / positive of the image selected in step S3, registers it as a subtraction mask image, and shifts to the subtraction mode (step S5). Then, the operation accepting unit 51 accepts an instruction to correct the misalignment between the mask image and the live image (perspective image) by the operator and notifies the setting unit 53 so that the setting unit 53 eliminates the misalignment. Is instructed to move the bed 17 (step S6). FIG. 6-3 shows the procedure of steps S5 to S6 together with related images.

  Then, the operation receiving unit 51 receives a 3D road map start instruction from the operator (step S7) and notifies the 3D road map processing unit 55, and the 3D road map processing unit 55 displays the 3D road map (step S7). S8). FIG. 6-4 shows the procedure of steps S7 to S8 together with related images.

  As described above, the setting condition specifying unit 52 determines the SID, FOV, and bed height at the time of image collection from the information of the 3D-DSA unsub-image whose main rotation is near 0 degrees among the 3D-DSA unsub-images from which the mask image is reconstructed. The arm angle is specified, and the setting unit 53 automatically sets the SID, FOV, bed height, and arm angle specified by the setting condition specifying unit 52, thereby facilitating alignment between the mask image and the fluoroscopic image. it can.

  As described above, in the present embodiment, the 3D road map display control unit 50 automatically sets the SID, FOV, bed height, and arm angle at the time of acquiring the mask image when starting the 3D road map. Alignment for the road map can be facilitated. In addition, because of the 3D roadmap, it is possible to reduce the exposure and use of the contrast agent as compared with the case of collecting 3D images again. Further, as compared with the case where alignment is performed using the shape of the wire and the mask image, it is not necessary to advance the wire to a position that can be aligned with the mask image, and the difficulty of the procedure can be reduced.

  In the above embodiment, the height of the bed can be adjusted from the image information, but the head height at the time of image collection and the head height at the time of 3D roadmap are slightly different depending on how to put the pillow. It can happen. Accordingly, there is a case where correction in the height direction is necessary in addition to correction in the horizontal direction of the bed. In such a case, instead of extracting an image whose arm main rotation angle is near 0 degrees in step S3 shown in FIG. 5, not only an image near 0 degrees but also an image near 90 degrees is selected as step S3 ′. After extracting and adjusting in the horizontal direction in steps S4 to S6, the operator automatically performs fine adjustment in the height direction by automatically setting to the setting at the time of image collection when the arm main rotation angle is around 90 degrees. Therefore, it is possible to eliminate the positional deviation.

  FIG. 8 shows a case where the alignment in the horizontal direction is performed using an image having an arm main rotation angle near 0 degrees, and then the alignment in the height direction is performed using an image having an arm main rotation angle near 90 degrees. Show. Here, the alignment in the height direction is performed after the alignment in the horizontal direction. However, the alignment in the horizontal direction can also be performed after the alignment in the height direction.

  Further, in step S6 shown in FIG. 5, the positional deviation correction designation by the operator is accepted and the positional deviation is eliminated. However, the positional deviation can be corrected automatically. Specifically, the misregistration can be automatically corrected using an auto pixel shift technique used in the DSA image. That is, the displacement between the transmission image and the DSA image is calculated using a displacement correction technique used in the DSA image, and the amount of movement of the bed 17 is calculated from the calculated displacement between the pixels to automatically correct the displacement. be able to.

  In the present embodiment, the case where a 3D-VR image (mask image) is displayed on the monitor 34 of the digital fluorography apparatus 100 has been described. However, the present invention is not limited to this, and for example, 3D-VR. The same applies to the case where the digital fluorography apparatus 100 identifies the mask image by displaying the image on the 3D workstation and notifying the digital fluorography apparatus 100 of the information of the 3D-VR image selected by the 3D workstation. can do. By displaying the 3D-VR image of the 3D workstation, it is possible to display a 3D-VR image using the 3D processing and the 3D display capability of the 3D workstation.

  In this embodiment, the digital fluorography apparatus has been described. However, the present invention is not limited to this, and can be similarly applied to an apparatus that monitors a subject using X-rays.

  As described above, the X-ray imaging apparatus and the three-dimensional road map alignment method according to the present invention are useful for an X-ray apparatus having a three-dimensional road map function, and in particular, accurately position a fluoroscopic image and a mask image. Suitable when it is necessary to match.

It is explanatory drawing for demonstrating the 3D road map position alignment method which concerns on a present Example. It is a functional block diagram which shows the structure of the digital fluorography apparatus concerning a present Example. It is a figure which shows the structural example of a display part and an operation part. It is a functional block diagram which shows the structure of a 3D road map display control part. It is a flowchart which shows the process sequence of the 3D road map display control process by a 3D road map display control part. It is a figure (1) which shows the process by a 3D road map display control part, and a related image. It is FIG. (2) which shows the process by a 3D road map display control part, and a related image. It is a figure (3) which shows processing by a 3D road map display control part, and a related picture. It is FIG. (4) which shows the process by a 3D road map display control part, and a related image. It is a figure which shows the example of a setting of SID, FOV, bed height, and arm angle. It is a figure which shows the position alignment of the height direction after the position alignment of a horizontal direction. It is explanatory drawing for demonstrating position alignment of a fluoroscopic image and 3D mask image. It is a figure which shows the blood vessel running of 3D-VR mask image, and alignment from the shape of the wire of a fluoroscopic image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray generation part 2 X-ray detection part 3 Mechanism part 4 High voltage generation part 5 Holding arm 6 Mechanism control part 7 Image calculation / memory | storage part 8 Display part 9 Operation part 10 System control part 11 Image data generation part 12 Image calculation circuit DESCRIPTION OF SYMBOLS 13 Image data memory circuit 15 X-ray tube 16 X-ray restrictor 17 Bed 21 Planar detector 22 Gate driver 23 Charge / voltage converter 24 A / D converter 25 Parallel / serial converter 31 Display image memory 32 D / A Converter 33 Display circuit 34 Monitor 41 Holding arm moving mechanism 42 Sleeper moving mechanism 45 Patient 50 3D road map display control unit 51 Operation receiving unit 52 Setting condition specifying unit 53 Setting unit 54 Subtraction processing unit 55 3D road map processing unit 100 Digital fluoro Graphic equipment

Claims (7)

An X-ray imaging apparatus having a three-dimensional road map function,
A setting condition specifying means for specifying a setting condition of the apparatus when image data of an image to be used as a mask image of a three-dimensional road map is collected;
Condition setting means for setting the apparatus to the setting condition specified by the setting condition specifying means;
An X-ray imaging apparatus comprising:   The setting condition specifying unit specifies the setting condition of the apparatus when the image data of the 3D acquisition image whose arm angle is closest to a predetermined angle among the plurality of 3D acquisition images that are the basis of the mask image is acquired. The X-ray imaging apparatus according to claim 1, wherein:   The setting condition specifying unit specifies the setting condition of the apparatus when the image data of the 3D acquired image having the arm angle closest to 0 degree is collected among the plurality of 3D acquired images that are the basis of the mask image. The X-ray imaging apparatus according to claim 2.   The image forming apparatus according to claim 1, further comprising a misalignment correcting unit that performs horizontal alignment by subtraction using an image obtained by inverting a negative / positive image of the 3D acquired image having an arm angle closest to 0 degrees as a mask image. 3. The X-ray imaging apparatus according to 3. The setting condition specifying means includes the setting condition of the apparatus and the arm angle when the image data of the 3D acquired image having the arm angle closest to 0 degrees is collected among the plurality of 3D acquired images that are the basis of the mask image. Specifies the setting conditions of the device when the image data of the collected image for 3D closest to 90 degrees is collected,
The condition setting means matches the setting of the apparatus to the setting condition of the apparatus when the image data of the 3D acquired image whose arm angle is closest to 0 degrees is collected, and the condition setting means uses 3D for the arm angle closest to 90 degrees. 5. The X-ray imaging apparatus according to claim 3, wherein the setting of the apparatus is matched with the setting condition of the apparatus when the image data of the collected image is collected.   The setting conditions specified by the setting condition specifying means and set by the condition setting means include a distance between the X-ray tube focal point and the X-ray detector, an image field size, a bed height, and an arm angle. The X-ray imaging apparatus according to claim 1, wherein: A three-dimensional road map alignment method by an X-ray imaging apparatus having a three-dimensional road map function,
A setting condition specifying step for specifying a setting condition of the apparatus when image data of an image to be used as a mask image of a three-dimensional road map is collected;
A condition setting step for setting the apparatus to the setting condition specified by the setting condition specifying step;
A three-dimensional roadmap registration method characterized by comprising:

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