JP2017051418A - Radiographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiographic apparatus capable of quickly obtaining three-dimensional image data of an interest object when a surgical procedure such as intervention treatment is conducted.SOLUTION: A region-of-interest extraction unit 39 extracts a designated region as a region of interest from each of a series of two-dimensional images P. A reconstruction unit 41 reconstructs a three-dimensional image of a region in which a stent is contained, based on images corresponding respectively to the regions of interest. Specifically, the reconstruction unit 41 performs reconstruction using an image of the region of interest corresponding to a portion of the whole with respect to each of the series of two-dimension images P, so that the time to reconstruct the region containing a stent can be reduced. Three-dimensional image data can thus be quickly obtained for a region requiring reconstruction, thereby substantially reducing the time required for diagnosis, with the burden on the operator and on the subject being lessened.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a radiation imaging apparatus that is effective for interventional treatment and the like that captures an image of a region including a device inserted into a body of a subject, and particularly relates to a technique for generating and displaying a three-dimensional image of a device.

    In the medical field, interventional treatment (IVR: Interventional Radiography) is performed on a patient whose blood vessel is narrowed by atheroma or calcified blood vessel wall. In interventional treatment, a catheter having a guide wire inside is inserted into the blood vessel of the subject, and treatment is performed on the affected part of the narrowed blood vessel.

  Examples of the intravascular treatment using a catheter include stent placement using a stent in addition to cutting of a blood vessel wall using a roller blader. The stent is a grid-like cylindrical body made of a metal wire such as stainless steel, and a balloon is provided inside. In IVR, a stent is placed on a narrowed portion of a blood vessel. Then, the placed stent is expanded by a balloon to open the stent. By placing the expanded stent in the blood vessel, the narrowed portion of the blood vessel can be expanded and the blood flow can be kept normal.

  When performing an IVR technique using a stent, a radiographic image is taken using a radiographic apparatus in order to confirm the position of the stent. That is, the surgeon irradiates the subject with a low dose of radiation, and continuously acquires radiation images on which the catheter and stent are projected. The operator can check the position of the catheter or stent in the blood vessel at any time with reference to the continuously displayed real-time radiographic images, and can keep the stent at an appropriate position of the stenosis.

  In recent years, in order to further improve the therapeutic effect, there is an increasing need to acquire a three-dimensional image showing a region including a stent during IVR treatment. As an example of a conventional radiation imaging apparatus that can acquire a three-dimensional image of a stent, a configuration as shown in Patent Document 1 can be given. As shown in FIG. 17A, the radiation imaging apparatus 101 according to the conventional example includes a top plate 103 on which a subject M having a horizontal posture is placed, a radiation source 105, and a radiation detector 107. As an example of the radiation detector 107, a flat panel detector (FPD) or the like is used.

  The radiation source 105 and the radiation detector 107 are disposed to face each other with the top plate 103 interposed therebetween, and are provided at one end and the other end of the C-arm 109, respectively. The C-shaped arm 109 is configured to slide along the arc path of the C-shaped arm 109 indicated by the symbol RA. Furthermore, the C-shaped arm 109 is configured to be rotatable around a horizontal axis RB parallel to the x direction (the longitudinal direction of the top plate 103 and the body axis direction of the subject M).

  An image generation unit 111 is provided at the subsequent stage of the radiation detector 107. The image generation unit 111 generates a radiation image (two-dimensional image) of a region including the object of interest based on the radiation detection signal output from the radiation detector 107. The reconstruction unit 113 reconstructs a plurality of radiation images generated by the image generation unit 111 to generate a three-dimensional image of a region including the object of interest.

  When generating a three-dimensional image using the radiation imaging apparatus 101, the C-arm 109 is rotated approximately halfway around the horizontal axis RB. The radiation source 105 and the radiation detector 107 maintain a positional relationship facing each other with the top plate 103 interposed therebetween, and follow an arc trajectory RC that rotates around an axis in the x direction around the region of interest Mo of the subject M. Approximately half a turn. That is, as shown in FIG. 17B, the radiation source 105 rotates from the imaging position indicated by reference numeral 105a to the imaging position indicated by reference numeral 105c via the imaging position indicated by reference numeral 105b.

  The radiation source 105 irradiates the subject M with radiation at each of the imaging positions 105a to 105c. Based on the radiation detection signal output from the radiation detector 107, the image generation unit 111 acquires a radiation image that reflects a cross section in the direction in which the blood vessel 115 extends (long axis direction of the blood vessel 115). The radiographic images acquired at the imaging positions 105a to 105c are assumed to be two-dimensional images Pa to Pc, respectively. As shown in FIG. 17C, the two-dimensional images Pa to Pc are radiographic images taken from various directions about the axis of the subject M in the body axis direction with respect to the stent 119 and the blood vessel 115 of interest. is there.

  The reconstruction unit 113 reconstructs a series of two-dimensional images Pa to Pc to generate a three-dimensional image T as shown in FIG. The three-dimensional image T displays three-dimensional image data of the blood vessel 115 having the branch tube 117 and the stent 119. Then, based on the three-dimensional image T, a radiographic image showing a cross section in the major axis direction (long axis cross section) of the stent 119 and a radiographic image showing a cross section perpendicular to the long axis cross section (short axis cross section) are generated. Are displayed side by side.

  The long-axis cross-sectional radiation image (long-axis cross-sectional image) is a cross-sectional image perpendicular to the y direction, and the short-axis cross-sectional radiation image (short-axis cross-sectional image) is a cross-sectional image perpendicular to the x direction. Therefore, the surgeon refers to the long-axis cross-sectional image and the short-axis cross-sectional image that are in the relationship of the plane images orthogonal to each other, so that when the IVR treatment is performed, accurate information on the stent 119 is obtained in each of the three-dimensional directions. Can be confirmed.

  In recent years, a radiography apparatus that generates a virtual endoscopic image based on three-dimensional image information obtained using a radiographic image when diagnosing the inside of a tubular body such as a blood vessel or a digestive tract has been reported. (For example, Patent Document 2). When performing diagnosis using a virtual endoscopic image, the position of the viewpoint with respect to the image can be arbitrarily set unlike a normal endoscopic diagnosis. Therefore, endoscopic observation can be performed based on the set viewpoint position, and more appropriate diagnosis can be performed.

JP 2005-287524 A JP 2013-27697 A

However, the conventional example having such a configuration has the following problems.
That is, in the conventional apparatus, since the calculation performed to reconstruct a 3D image from a 2D image is complicated, it takes a long time to complete the image reconstruction calculation and acquire the 3D image. To do. Therefore, when acquiring a three-dimensional image during the IVR, the operator simply waits for a long time until the calculation of reconstruction is completed and the three-dimensional image is actually acquired. Therefore, since a wasteful time is spent during the treatment of the IVR, the time required for the IVR becomes long. As a result, there is a concern that the burden on the operator and the subject will increase and the efficiency of IVR will decrease.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a radiation imaging apparatus that can quickly acquire 3D image data of interest when performing IVR or the like.

In order to achieve such an object, the present invention has the following configuration.
That is, a radiation imaging apparatus according to the present invention includes a radiation source that irradiates a subject with radiation, a radiation detection unit that detects the radiation that has passed through the subject, and an imaging system that includes the radiation source and the radiation detection unit. Imaging system moving means for respectively moving the object along a predetermined trajectory with respect to the subject, and control for repeating radiation irradiation to the radiation source while the imaging system moves along the predetermined trajectory with respect to the subject, respectively. And a two-dimensional image of a region including a device inserted into the body of the subject based on a radiation detection signal output from the radiation detection means each time the radiation source performs radiation irradiation. A predetermined region including a part of the device is selected from each of the image generation means to be generated and the two-dimensional image generated by the image generation means. A region of interest extracted based on each of the images corresponding to the region of interest extracted by the region of interest extraction unit from each of the series of two-dimensional images generated by the image generation unit. Reconstructing means for reconstructing a three-dimensional image.

  [Operation / Effect] According to the radiation imaging apparatus of the present invention, the attention area extraction means extracts a predetermined area including a part of the device from each of the series of two-dimensional images as the attention area. The reconstruction means reconstructs a three-dimensional image of the region of interest based on each of the image portions corresponding to the region of interest. The attention area used for reconstruction of the three-dimensional image corresponds to a part of the entire two-dimensional image. That is, the reconstructing unit does not need to perform calculations for reconstructing the entire image for a series of two-dimensional images when generating a three-dimensional image. As a result, since the three-dimensional image data can be quickly acquired for the area that needs to be reconstructed, the time required for diagnosis can be greatly shortened and the burden on the operator and the subject can be reduced.

  Further, in the above-described invention, an image cutout unit that cuts out the part of the device from the two-dimensional image to generate a cutout image, and a radiographic image of a cross section orthogonal to the major axis direction of the device based on the three-dimensional image It is preferable to include a short-axis cross-sectional image generating unit that generates a short-axis cross-sectional image, and an image display unit that displays the cut-out image and the short-axis cross-sectional image in parallel.

  [Operation / Effect] The radiographic apparatus according to the present invention includes short-axis cross-sectional image generation means for generating, as a short-axis cross-sectional image, a radiographic image of a cross-section orthogonal to the long-axis direction of the device based on a three-dimensional image. . The image cutout means cuts out the device portion from the two-dimensional image to generate a cutout image. The image display means displays the cut-out image and the short-axis cross-sectional image in parallel.

  Each of the two-dimensional images is generated by irradiation with radiation while the imaging system moves along a predetermined trajectory with respect to the subject. That is, each of the two-dimensional images and the short-axis cross-sectional image have different viewpoint directions. Since two images with different viewpoint directions are displayed side by side, the surgeon can easily refer to the two images displayed in parallel to obtain information on the position and state of the device in each of the three-dimensional directions. You can get it. As a result, it is possible to perform a treatment requiring three-dimensional image data quickly and more accurately.

  The cut-out image is generated by cutting out a device portion from the two-dimensional image. That is, the device image shown in the cut-out image has higher visibility than the device image shown in the two-dimensional image. Therefore, the surgeon can confirm more precise information about the position of the device by referring to the cutout image.

  In the above-described invention, a feature point extracting unit that extracts a feature point from the two-dimensional image, and a plurality of the two-dimensional images that are superimposed on the basis of the feature point extracted by the feature point extracting unit are integrated images. It is preferable that the image cut-out unit generates the cut-out image by cutting out the part of the device from the integrated image.

  [Operation / Effect] According to the radiation imaging apparatus of the present invention, the integrating means generates an integrated image by superimposing a plurality of two-dimensional images on the basis of the feature points. By superimposing a plurality of two-dimensional images, the image of the device shown in the accumulated image becomes more visible. The image cutout unit cuts out the device portion from the integrated image to generate a cutout image, and the image display unit displays the cutout image cut out from the integrated image and the short-axis cross-sectional image in parallel. Therefore, the surgeon can acquire more precise device information by referring to the cut-out image and the short-axis cross-sectional image with high device visibility.

  Moreover, in the above-described invention, it is preferable to include attention area display means for displaying a range of the attention area with respect to the clipped image displayed on the image display means.

  [Operation / Effect] The radiation imaging apparatus according to the present invention includes attention area display means for displaying the range of the attention area with respect to the clipped image displayed on the image display means. In this case, the surgeon can easily confirm the portion of the image used to generate the short-axis cross-sectional image in the cut-out image by referring to the position of the attention area displayed in the cut-out image. As a result, more precise three-dimensional information can be acquired regarding the position of the device.

  In the above-described invention, the image processing apparatus further includes attention area setting means for arbitrarily setting a position and a size of the attention area displayed in the cut-out image, and the attention area extraction means is set by the attention area setting means. It is preferable to extract an image corresponding to the attention area from each of the two-dimensional images based on the attention area.

  [Operation / Effect] According to the radiation imaging apparatus of the present invention, the attention area setting means arbitrarily sets the position and size of the attention area displayed in the clipped image. The attention area extraction means extracts an image corresponding to the attention area from each of the two-dimensional images based on the attention area set by the attention area setting means. In this case, the position and size of the attention area can be arbitrarily changed as necessary. Therefore, the surgeon can arbitrarily set a region for which a short-axis cross-sectional image is to be confirmed as a region of interest with reference to the cut-out image. As a result, more detailed three-dimensional information regarding the position and state of the device can be acquired.

  Further, in the above-described invention, the size of each of the plurality of short-axis cross-sectional images generated based on the three-dimensional image is corrected so as to become larger as the viewpoint is closer to the short-axis cross-sectional image. It is preferable that virtual endoscopic image generation means for generating a virtual endoscopic image of the region of interest by superimposing each of the short-axis cross-sectional images that have been performed is provided.

  [Operation / Effect] The radiation imaging apparatus according to the present invention includes virtual endoscopic image generation means for generating a virtual endoscopic image of the region of interest. The virtual endoscopic image is obtained by correcting the size of each of the plurality of short-axis cross-sectional images generated based on the three-dimensional image so that the size becomes closer to the viewpoint with respect to the short-axis cross-sectional image. Generated by superimposing each of the axial cross-sectional images.

  In this case, in the virtual endoscopic image, an image at a position close to the viewpoint is large and an image at a distant position is small. Therefore, information equivalent to the endoscopic image can be obtained by referring to the virtual endoscopic image. Therefore, it is possible to generate a virtual endoscopic image for the region of interest without inserting an endoscope into the subject and perform endoscopic observation of the device.

  The virtual endoscopic image is generated based on the three-dimensional image. That is, the virtual endoscopic image is generated not based on the entire series of two-dimensional images but based on each of a part of the images corresponding to the attention area. As a result, the time required to generate the virtual endoscopic image can be shortened. Therefore, a treatment requiring a virtual endoscopic image can be performed more quickly and efficiently.

  In the above-described invention, it is preferable that the image display unit displays the cut-out image and the virtual endoscopic image in parallel.

  [Operation / Effect] According to the radiation imaging apparatus of the present invention, the image display means displays the cut-out image and the virtual endoscope image in parallel. Since the virtual endoscopic image is generated by superimposing the short-axis cross-sectional images, the cut-out image and the virtual endoscopic image have different viewpoint directions. Since two images having different viewpoint directions are displayed in parallel, the surgeon can easily acquire three-dimensional information regarding the position and state of the device by referring to the two images displayed in parallel. As a result, it is possible to perform a treatment requiring three-dimensional image data quickly and more accurately.

  In the above-described invention, it is preferable that the device further includes a contour display unit that detects a contour of the device reflected in the short-axis cross-sectional image and displays the detected contour on the short-axis cross-sectional image.

  [Operation / Effect] According to the radiation imaging apparatus of the present invention, the contour display means detects the contour of the device reflected in the short-axis cross-sectional image and displays the detected contour on the short-axis cross-sectional image. Therefore, the visibility of the device becomes higher in the short-axis cross-sectional image or the virtual endoscopic image. Therefore, the three-dimensional information of the device can be confirmed more easily.

  Further, in the above-described invention, a reference point extracting means for extracting a reference point from the two-dimensional image, and a position of the device in which each of the series of two-dimensional images is reflected in the two-dimensional image based on the reference point. Image correction means for correcting the images so as to be the same, and the attention area extraction means extracts an image of a portion corresponding to the attention area from a series of the two-dimensional images corrected by the image correction means. preferable.

  [Operation / Effect] According to the radiographic apparatus according to the present invention, the image correcting unit is configured so that each of the series of two-dimensional images has the same position of the device shown in the two-dimensional image, based on the reference point. to correct. In this case, even if the position of the device reflected in each two-dimensional image is different, the position of the device reflected in each two-dimensional image becomes the same by the image correction means. Since the image correction means corrects the two-dimensional image based on the reference point, the device is accurately aligned in the two-dimensional image.

  Therefore, a high-contrast device image can be obtained in the three-dimensional image generated by reconstructing the corrected two-dimensional image. Therefore, even when the device moves at high speed due to a heartbeat or the like, such as during an IVR treatment, a high-quality three-dimensional image that reflects the region including the device can be acquired in real time. The surgeon can perform IVR with higher accuracy using a three-dimensional image showing a high-quality device.

  According to the radiation imaging apparatus of the present invention, the attention area extraction unit extracts a predetermined area including a part of the device from each of the series of two-dimensional images as the attention area. The reconstruction means reconstructs a three-dimensional image of the region of interest based on each of the image portions corresponding to the region of interest. The attention area used for reconstruction of the three-dimensional image corresponds to a part of the entire two-dimensional image. That is, the reconstructing unit does not need to perform calculations for reconstructing the entire image for a series of two-dimensional images when generating a three-dimensional image. As a result, since the three-dimensional image data can be quickly acquired for the area that needs to be reconstructed, the time required for diagnosis can be greatly shortened and the burden on the operator and the subject can be reduced.

1 is a front view illustrating a schematic configuration of a radiation imaging apparatus according to Embodiment 1. FIG. 1 is a functional block diagram illustrating a configuration of a radiation imaging apparatus according to Embodiment 1. FIG. 1 is a schematic diagram illustrating a configuration of a catheter system according to Example 1. FIG. (A) is a diagram of the catheter system when the stent is in an unexpanded state, and (b) is a diagram of the catheter system when the stent is in an expanded state. (A) is a flowchart explaining the operation | movement process in Example 1, (b) is a flowchart explaining the operation | movement process in Example 2. FIG. It is the schematic explaining the positional relationship in the blood vessel of the catheter system which concerns on Example 1. FIG. It is a figure explaining the process of step S2 which concerns on Example 1. FIG. (A) is a figure explaining each imaging | photography position in 1 scan, (b) is a figure which shows the two-dimensional image produced | generated in each imaging | photography position. It is a figure explaining the process of step S3 which concerns on Example 1. FIG. The upper figure shows a process of generating an integrated image by superimposing two-dimensional images, and the lower figure shows a process of generating a cut-out image by rotating and enlarging an image cut out from the integrated image. It is a figure explaining the process of step S4 which concerns on Example 1. FIG. (A) is a figure which shows the cut-out image on which the attention area was superimposed, (b) is a figure which shows the state which the attention area translated, (c) shows the state which expanded the range of the attention area. FIG. It is a figure explaining the process of step S5 which concerns on Example 1. FIG. The upper part is a diagram showing each two-dimensional image in which the attention area is displayed, the lower part is a figure showing the three-dimensional image generated by reconstructing the attention area of the two-dimensional image, and the lower part is the figure showing the three-dimensional image. It is a figure which shows the short-axis cross-sectional image produced | generated based on this. It is a figure explaining the process of step S5 which concerns on Example 1. FIG. (A) is a figure which shows the combined image which displays a cut-out image and a short-axis cross-sectional image in parallel, (b) is a figure which shows the combined image in the state which translated the attention area, (c) is It is a figure which shows the joint image in the state which expanded the stent. 6 is a functional block diagram illustrating a configuration of a radiation imaging apparatus according to Embodiment 2. FIG. FIG. 9 is a diagram for explaining the operation of the radiation imaging apparatus according to the second embodiment. (A) The left is a figure which shows the attention area displayed on a cut-out image, and the right is a figure explaining the small area which expands an attention area and comprises an attention area. (B) is a figure which shows the short-axis cross-sectional image produced | generated in each of a small area | region, (c) is a figure which shows the short-axis cross-sectional image by which the outline of the stent was displayed. It is a figure explaining the process of step S6 which concerns on Example 1. FIG. The upper row is a diagram showing each short-axis cross-sectional image before image processing, the middle row is a diagram showing each short-axis cross-sectional image after image processing, and the lower row is a superposition of the short-axis cross-sectional images after image processing. It is a figure which shows the produced | generated virtual endoscope image. FIG. 10 is a diagram illustrating a combined image according to a second embodiment. It is a figure which shows the short-axis cross-sectional image by which the outline of the stent was displayed in the radiography apparatus which concerns on a modification. (A) is a figure which shows the outline of the stent at the time of expanding uniformly, (b) is a figure which shows the outline of the stent at the time of expanding nonuniformly. It is a functional block diagram explaining the structure of an image process part in the radiography apparatus which concerns on a modification. It is a figure explaining the structure of the radiography apparatus which concerns on a prior art example. (A) It is a front view explaining the structure of the radiography apparatus which concerns on a prior art example, (b) is a figure explaining each imaging position in 1 scan, (c) is the two-dimensional produced | generated in each imaging position It is a figure which shows an image, (d) It is a figure of the three-dimensional image which concerns on the prior art example produced | generated by reconstructing each whole of a two-dimensional image.

  Embodiment 1 of the present invention will be described below with reference to the drawings. In addition, it demonstrates using an X-ray as an example of a radiation. FIG. 1 is a schematic diagram illustrating the configuration of the radiation imaging apparatus according to the first embodiment.

<Description of overall configuration>
The radiation imaging apparatus 1 according to the first embodiment includes a top 3 on which a subject M in a horizontal posture is placed, an X-ray tube 5 that irradiates the subject M with X-rays, and irradiation from the X-ray tube 5. And an X-ray detector 7 for detecting the converted X-ray and converting it into an electric signal. The X-ray tube 5 and the X-ray detector 7 are arranged to face each other with the top plate 3 interposed therebetween. The X-ray tube 5 and the X-ray detector 7 constitute an imaging system.

  The X-ray detector 7 has a detection surface for detecting X-rays, and pixels as X-ray detection elements on the detection surface are in the form of a two-dimensional matrix of about 4,096 lines × 4,096 lines as an example. Is arranged. In the first embodiment, a flat panel detector (FPD) is used as the X-ray detector 7. The X-ray tube 5 corresponds to the radiation source in the present invention, and the X-ray detector 7 corresponds to the radiation detection means in the present invention.

  The X-ray tube 5 and the X-ray detector 7 are provided at one end and the other end of the C-arm 9, respectively. The C-shaped arm 9 is held by an arm holding member 11 and is configured to slide along the arc path of the C-shaped arm 9 indicated by reference sign RA. The arm holding member 11 is disposed on the side surface portion of the support column 13 and can rotate around the horizontal axis RB parallel to the x direction (the longitudinal direction of the top 3 and the body axis direction of the subject M). Configured as follows. The C-shaped arm 9 held by the arm holding member 11 rotates around the axis in the x direction according to the arm holding member 11.

  The support column 13 is supported by a support base 15 disposed on the floor surface, and is configured to be horizontally movable in the y direction (the short direction of the top plate 3). The arm support member 11 and the C-arm 9 supported by the support column 13 move in the y direction according to the horizontal movement of the support column 13. The collimator 17 is provided in the X-ray tube 5 and limits the X-rays emitted from the X-ray tube 5 to a fan shape having a fan angle θ, for example.

  Here, the configuration of the radiation imaging apparatus 1 will be described in more detail. As shown in FIG. 2, the radiation imaging apparatus 1 includes an X-ray irradiation control unit 19, a detector control unit 21, an arm drive control unit 23, an imaging position detection unit 25, and an image processing unit 27. .

  The X-ray irradiation control unit 19 is configured to output a high voltage to the X-ray tube 5. Based on the high voltage output given by the X-ray irradiation control unit 19, the X-ray dose irradiated by the X-ray tube 5 and the timing of X-ray irradiation are controlled. The detector control unit 21 controls the operation of reading the charge signal converted by the X-ray detector 7, that is, the X-ray detection signal.

  The arm drive control unit 23 controls the sliding movement of the C-arm 9. As the C-arm 9 slides in the direction indicated by the symbol RA, the spatial positions of the X-ray tube 5 and the X-ray detector 7 change while maintaining the opposed arrangement state. The arm drive control unit 23 controls the rotational movement of the arm support member 11 in addition to the sliding movement of the C-arm 9. Since the X-ray tube 5 and the X-ray detector 7 are provided on the C-type arm 9, the spatial positions of the X-ray tube 5 and the X-ray detector 7 are changed in accordance with the rotational movement of the arm support member 11 while maintaining the opposed arrangement state. The arm drive control unit 23 corresponds to the imaging system moving means in the present invention.

  The slide movement amount of the C-type arm 9 and the rotational movement amount of the arm support member 11 are detected by a plurality of sensors 9a attached to the C-type arm 9 and the arm support member 11, respectively. Each detection signal of the sensor 9 a is transmitted to the imaging position detection unit 25. The imaging position detection unit 25 detects position information of an imaging system composed of the X-ray tube 5 and the FPD 7 based on each detection signal. The imaging position detection unit 25 detects the direction of the central axis of the X-rays irradiated from the X-ray tube 5 (X-ray irradiation axis direction) based on each detection signal.

  The image processing unit 27 includes an image generation unit 29, a feature point extraction unit 31, an integration unit 33, an image cutout unit 35, a region of interest display unit 37, a region of interest extraction unit 39, a reconstruction unit 41, And a cross-sectional image generator 43. The image generation unit 29 is provided at the subsequent stage of the X-ray detector 7, and based on the X-ray detection signal output from the X-ray detector 7, an X-ray image (a region including an object of interest of the subject M) 2D image). The image generation unit 29 corresponds to the image generation means in the present invention.

  The feature point extraction unit 31 is provided after the image generation unit 29 and extracts feature points from each of the two-dimensional images generated by the image generation unit 29. The integrating unit 33 integrates and superimposes a plurality of two-dimensional images on the basis of the feature points extracted by the feature point extracting unit 31 to generate an integrated image. The image cutout unit 35 cuts out an interest object displayed in the accumulated image and an image in the vicinity of the interest object, appropriately rotates and enlarges the image, and generates a cutout image. The feature point extraction unit 31 corresponds to a feature point extraction unit and a reference point extraction unit in the present invention. The integrating unit 33 corresponds to the integrating unit in the present invention. The image cutout unit 35 corresponds to the image cutout means in the present invention.

  The attention area display unit 37 displays information indicating a predetermined area (attention area) set by the input unit 45 described later, and information indicating each of the position and direction of the viewpoint with respect to the attention area on the cutout image. The attention area extraction unit 39 extracts an image of a part corresponding to the attention area from each of the two-dimensional images generated for one scan. One scan means X-ray irradiation performed while the C-arm 9 rotates a predetermined angle around the horizontal axis RB. The attention area display section 37 corresponds to attention area display means in the present invention, and the attention area extraction section 39 corresponds to attention area extraction means in the present invention.

  The reconstruction unit 41 reconstructs each of the images of the attention area extracted by the attention area extraction unit 39, and generates a three-dimensional image showing the area including the target of interest. The cross-sectional image generation unit 43 generates an X-ray image in an arbitrary cross section of the three-dimensional image based on the three-dimensional image reconstructed by the reconstruction unit 41. As an example of the X-ray image generated by the cross-sectional image generation unit 43, an X-ray image of a cross section orthogonal to a two-dimensional image, that is, an X-ray image (short-axis cross-sectional image) of a cross section perpendicular to the long axis direction of a stent described later. Is mentioned. The reconstruction unit 41 corresponds to reconstruction means in the present invention. The cross-sectional image generator 43 corresponds to the short-axis cross-sectional image generator in the present invention.

  The radiation imaging apparatus 1 further includes an input unit 45, a monitor 47, a storage unit 49, and a main control unit 51. The input unit 45 inputs an operator's instruction, and examples thereof include a mouse input type or keyboard input type panel, a touch input type panel, and the like. The input unit 45 has a configuration in which a region for executing reconstruction of a three-dimensional image is set as a region of interest in the two-dimensional image. In the monitor 47, the storage unit 39 displays various images such as a two-dimensional image, a three-dimensional image, and a short-axis cross-sectional image. The monitor 47 also has a configuration for displaying a plurality of types of images in parallel.

  The storage unit 49 stores various types of information related to various images generated by the image generation unit 29, the reconstruction unit 41, and the like, each position of the imaging system, and the X-ray irradiation axis direction of the X-ray tube 5. The main control unit 51 performs overall control of each of the X-ray irradiation control unit 19, the detector control unit 21, the arm drive control unit 23, the image processing unit 27, the monitor 47, and the storage unit 49. The input unit 45 corresponds to the attention area setting means in the present invention, and the monitor 47 corresponds to the image display means in the present invention.

  FIG. 3 is a schematic view showing a configuration of a catheter system 53 used for interventional treatment. The catheter system 53 includes a catheter 55, a guide wire 57, and a stent 59. The guide wire 57 is inserted into the tubular catheter 55. The stent 59 is provided inside the catheter 55 and has a configuration that allows movement in the direction indicated by the arrow along the guide wire 57. The stent 59 corresponds to the device in the present invention.

  The stent 59 is formed in the shape of a mesh using a strut 61 having a wire-like structure, and a balloon (not shown) is provided inside. In IVR, a non-expanded stent 59 shown in FIG. 3A is placed at a stenosis site in a blood vessel. Then, the arranged stent 59 is inflated with a balloon to be in the expanded state shown in FIG. By placing the expanded stent 59 in the blood vessel, the stenosis can be expanded and the blood flow can be kept normal.

  The strut 61 is made of a metal wire such as stainless steel. The strut 61 includes a plurality of corrugated struts 61a arranged at intervals in the major axis direction (J direction) of the stent 59 and connecting struts 61b that connect adjacent corrugated struts 61a. Such a configuration is an example of a configuration pattern of the strut 61 and may be changed as appropriate. A direction perpendicular to the major axis direction is defined as a minor axis direction. Examples of the minor axis direction include the G direction corresponding to the depth direction of the stent 59 shown in FIG. 3 and the H direction corresponding to the height direction of the stent 59.

  The stent 59 includes a plurality of markers 63. In the first embodiment, the number of markers 63 is two, but the number of markers 63 may be changed as appropriate. Of the two markers 63, one marker 63 a is provided on the distal end side in the long axis direction of the stent 59, and the other marker 63 b is provided on the proximal end side in the long axis direction of the stent 59. Each of the markers 63 is made of a radiopaque material and clearly indicates the position of the stent 59 in the X-ray image. Examples of the material constituting the marker 63 include gold, platinum, and tantalum. The stent 59 corresponds to the device in the present invention. The marker 63 corresponds to a feature point and a reference point in the present invention.

<Description of operation>
Next, the operation of the radiation imaging apparatus 1 according to the first embodiment will be described. FIG. 4 is a flowchart for explaining the operation of the radiation imaging apparatus according to the first embodiment. Here, a case where IVR is performed using a radiation imaging apparatus will be described as an example. The stent 59 will be described as an object of interest.

Step S1 (catheter insertion)
In performing the IVR, first, the subject M is placed on the top 3 as shown in FIG. Then, the operator makes a small hole in the base of the thigh of the subject M and inserts the catheter system 53 into the blood vessel. FIG. 5 shows a state in which the stent 59 is inserted into the blood vessel 65 together with the catheter 55 and the guide wire 57 with respect to the blood vessel 65 having the branch pipe 67. For convenience of explanation, the blood vessel 65 extends in the x direction (longitudinal direction of the top 3 and the body axis direction of the subject M), and the branch tube 67 extends downward from the blood vessel 65 in the z direction (vertical direction). And Further, it is assumed that the major axis direction (J direction) of the inserted stent 59 coincides with the x direction.

Step S2 (Generation of two-dimensional image)
After the catheter system 45 is inserted into the blood vessel of the subject M, a two-dimensional image is generated. The two-dimensional image generated in step S2 is used for generating a three-dimensional image described later. The surgeon operates the input unit 45 to continuously perform X-ray fluoroscopy while substantially rotating the arm holding member 11 about the horizontal axis RB parallel to the x direction. The predetermined angle for actually rotating the arm holding member 11 is preferably an angle obtained by adding the fan angle θ to 180 ° (about 200 °). The imaging system comprising the X-ray tube 5 and the X-ray detector 7 follows the arm holding member 11 around the body axis of the subject M (the axis in the x direction) while maintaining the positional relationship facing each other with the top plate 3 interposed therebetween. Move along a circular arc trajectory rotating around.

  Here, the operation of the X-ray tube 5 will be specifically described with reference to FIG. FIG. 6A is a diagram when the radiation imaging apparatus 1 is viewed from the foot side of the subject M in the x direction. For convenience of explanation, in FIG. 6A, the X-ray detector 7 and the like are omitted, and the positional relationship between the subject M and the X-ray tube 5 is illustrated.

  The X-ray tube 5 moves along an arc trajectory RC that substantially rotates about the axis in the x direction around the region of interest Mo. That is, the imaging position indicated by reference numeral 5a is sequentially rotated from the imaging position indicated by reference numeral 5b to 5d to the imaging position indicated by reference numeral 5e. In the first embodiment, the angle α at which the X-ray tube 5 rotates from 5a to 5e is an angle obtained by adding the fan angle θ to 180 °. In the first embodiment, X-ray irradiation performed while the X-ray tube 5 rotates from the reference numeral 5a to the reference numeral 5e is one scan.

  While the X-ray tube 5 moves from the imaging position 5a to the imaging position 5e, the X-ray tube 5 irradiates the subject M intermittently with a low dose of X-rays. Generally, the number of times of X-ray irradiation in one scan is several tens of times. For convenience of explanation, in Example 1, it is assumed that the X-ray tube 5 emits X-rays once at each of five imaging positions indicated by reference numerals 5a to 5e. The position and the number of times the X-ray tube 5 irradiates X-rays in one scan may be appropriately changed according to the conditions.

  X-rays transmitted through the subject M are detected by the X-ray detector 7. The detected X-ray is converted into an X-ray detection signal that is an electric signal, and the X-ray detection signal is output to the image generation unit 29. Based on the output X-ray detection signal, the image generation unit 29 intermittently generates a two-dimensional image P on which the stent 59, the blood vessel 65, and the like are projected. The two-dimensional images P generated by irradiating X-rays at the photographing positions 5a,..., 5e are referred to as two-dimensional images Pa,. Accordingly, in the first embodiment, five two-dimensional images P are generated during one scan.

  As shown in FIG. 6B, the two-dimensional images Pa to Pe are X-ray images taken from various directions around the axis in the x direction with respect to the stent 59 of interest. The two-dimensional image Pa and the two-dimensional image Pe are images obtained by photographing the object of interest from a substantially horizontal direction, and the two-dimensional image Pc is an image obtained by photographing the object of interest from a vertical direction. That is, each of the two-dimensional images Pa to Pe is an X-ray image (long-axis cross-sectional image) showing a cross-section parallel to each of the stent 59 in the long-axis direction.

  When generating each of the two-dimensional images P, the imaging position detection unit 25 detects the position of the imaging system and the X-ray irradiation axis direction of the X-ray tube 5 as needed. Information about the position of the imaging system and the X-ray irradiation axis direction information detected for each of the two-dimensional images P is transmitted to the reconstruction unit 41, and is used when a three-dimensional image is reconstructed. In this manner, a series of two-dimensional images Pa to Pe photographed from various positions in the circular arc trajectory rotating around the x-direction axis is generated. Each of the two-dimensional images Pa to Pe generated in the image generation unit 29 is transmitted to the feature point extraction unit 31.

Step S3 (Cutout image generation)
The feature point extraction unit 31 extracts the marker 63 as a feature point from each of the transmitted two-dimensional images Pa to Pe. Since each of the markers 63 is made of a radiopaque material, the visibility in the two-dimensional image is higher than that of the stent 59 and the blood vessel 65. Therefore, the feature point extraction unit 31 can accurately extract the marker 63. Each of the two-dimensional images Pa to Pe extracted using the marker 63 as a feature point is transmitted from the feature point extraction unit 31 to the integration unit 33.

  The accumulating unit 33 selects a predetermined number of images from the most recently generated image among a series of two-dimensional images P from which each of the markers 63 has been extracted. The integrating unit 33 integrates and superimposes each of the selected two-dimensional images P to generate an integrated image Q. For example, the number of two-dimensional images P used to generate the integrated image Q is eight, but the number of two-dimensional images P to be superimposed may be changed as appropriate.

  At this time, the integrating unit 33 superimposes the two-dimensional images P with each of the markers 63 as a reference, and generates an integrated image Q (FIG. 7, upper right). By using the marker 63 as a reference, the positioning of the stent 59 reflected in each of the two-dimensional images P is performed, so that the stent 59 is reflected as a highly visible image in the integrated image Q. In addition, since the integration unit 33 performs integration using the most recently generated two-dimensional image P, the integration image Q is an X-ray image showing a real-time image of the stent 59. The generated integrated image Q is transmitted from the integrating unit 33 to the image cutout unit 35.

  The image cutout unit 35 cuts out the image of the stent 59 and its neighboring area from the integrated image Q, and rotates the cutout image as appropriate (FIG. 7, lower left). Specifically, for the stent 59, it is preferable to rotate the clipped image so that the marker 63a is positioned at the upper center of the image and the marker 63b is positioned at the lower center of the image. Furthermore, the image cutout unit 35 generates a cutout image R by appropriately enlarging the rotated image (FIG. 7, lower right). The generated cutout image R is transmitted to the attention area display unit 37 and displayed on the monitor 47.

Step S4 (Setting of attention area)
The surgeon refers to the cutout image R displayed on the monitor 47 and sets a predetermined region including a part of the stent 59 as a region of interest. The attention area means a predetermined area in which a three-dimensional image is reconstructed among long-axis cross-sectional images (images in a cross section along the J direction) reflected in the cut-out image R. As shown in FIG. 8A, the attention area W is a rectangular area that passes through the midpoint between the marker 63 a and the marker 63 b, and the longitudinal direction of the attention area W extends in the short axis direction of the stent 59. In order to effectively perform interventional treatment, the length of the region of interest in the longitudinal direction is preferably about 4 mm. In order to quickly generate a three-dimensional image, it is preferable that the length of the attention area W in the short direction is a length corresponding to one pixel to several pixels in the cut-out image R.

  The position and range of the attention area W described above is an example of the attention area W in the initial state, and the surgeon operates the mouse or the touch panel provided in the input unit 45 to change the position and size of the attention area W as appropriate. it can. That is, the attention area display unit 37 translates the position of the attention area W as shown in FIG. Alternatively, as shown in FIG. 8C, the range of the attention area W is enlarged or reduced.

  Further, the surgeon operates the input unit 45 to set the position of the viewpoint and the direction of the viewpoint in the short-axis cross-sectional image generated later. The attention area display unit 37 displays the viewpoint information indicating the position and direction of the viewpoint on the cutout image R in accordance with the input instruction. As an example of the viewpoint information, an arrow indicated by a symbol D in FIG. In this case, the viewpoint direction with respect to the short-axis cross-sectional image is a direction from the marker 63b to the marker 63a. In this case, the viewpoint position is a predetermined position set by the operator on the marker 63a side from the attention area W. The viewpoint position is not shown below.

  Conversely, when the direction of the viewpoint is the direction from the marker 63b to the marker 63a, an arrow D 'as shown in FIG. 8B is displayed on the marker 63a side of the attention area W. In this case, the viewpoint position is a predetermined position on the marker 63a side from the attention area W. Each of the attention area W information and the viewpoint information is transmitted to the attention area extraction unit 39.

Step S5 (3D image reconstruction)
After setting the attention area W and the arrow D, reconstruction of the three-dimensional image is executed. That is, the attention area extraction unit 39 extracts an image of a part corresponding to the attention area W from each of the intermittently generated two-dimensional images P according to the position and range information of the attention area W (upper part of FIG. 9). The images of the attention area W in each of the two-dimensional images Pa to Pe are set as images Wa to We, respectively. Each of the extracted images Wa to We is sequentially transmitted to the reconstruction unit 41.

  The reconstruction unit 41 reconstructs the three-dimensional image Tw using each of the images Wa to We of the attention area W extracted from each of the two-dimensional images Pa to Pe. The three-dimensional image Tw is a three-dimensional image that displays the stent 59, blood vessels 65, and the like included in the region of interest W (lower left in FIG. 9). Examples of the configuration for generating the three-dimensional image Tw include a three-dimensional reconstruction algorithm using a filtered back projection method (FBP: Filtered Back Projection) or a successive approximation method.

  Information regarding the position of the imaging system detected for each of the two-dimensional images Pa to Pe and the X-ray irradiation axis direction of the X-ray tube 5 is transmitted from the imaging position detection unit 25 to the reconstruction unit 41. Yes. The reconstruction unit 41 associates each of the images extracted from the two-dimensional images Pa to Pe with the position information of the imaging system corresponding to each two-dimensional image P and the information on the X-ray irradiation axis direction. Based on the associated information, the reconstruction unit 41 reconstructs each image of the attention area W extracted from the two-dimensional images Pa to Pe to generate a three-dimensional image Tw. The generated three-dimensional image Tw is displayed on the monitor 47.

  By reconstructing a plurality of images P including the image of the stent 59, the same effect as when the images of the stent 59 are superimposed can be obtained. Therefore, the visibility of the stent 59 reflected in the three-dimensional image Tw is higher than the visibility of the stent 59 reflected in each two-dimensional image P. Image data of the three-dimensional image Tw is transmitted to the cross-sectional image generator 43.

  Note that the reconstruction unit 41 sequentially performs reconstruction processing using images that are sequentially transmitted in accordance with rotational imaging of the imaging system, and sequentially displays the reconstruction images generated by the reconstruction processing. That is, after the two-dimensional image Pa is generated at the photographing position 5 a, the attention area extraction unit 39 extracts the image Wa of the attention area W and transmits it to the reconstruction unit 41. Then, while the image Wa is extracted and transmitted, the imaging system moves to the imaging position 5b by the rotational movement of the C-shaped arm 9, and captures the two-dimensional image Pb. As described above, the images Wa to We are sequentially extracted during the rotational shooting of the imaging system, and are sequentially transmitted to the reconstruction unit 41.

  The reconstruction unit 41 performs sequential reconstruction processing using images sequentially transmitted to the reconstruction unit 41 among the images Wa to We. As an example, the image Wa and the image Wb are transmitted to the reconstruction unit 41. At the time when each of the imaging systems captures the two-dimensional image Pc at the capturing position 5c, the reconstruction unit 41 uses the information of the image Wa and the image Wb. Based on this, the 3D image Tw is reconstructed, and the 3D image Tw is displayed on the monitor 47 in real time.

  Then, the image Wc is extracted from the two-dimensional image Pc and transmitted to the reconstruction unit 41. When each of the imaging systems moves from the shooting position 5c to the shooting position 5d, the reconstruction unit 41 uses the images Wa to Wc. Then, the three-dimensional image Tw is reconstructed, and the generated three-dimensional image Tw is displayed in real time. In this way, by sequentially processing the images that are sequentially transmitted in accordance with the rotation imaging of the imaging system, the three-dimensional image is sequentially reconstructed in real time while the imaging system sequentially moves to each imaging position.

  As described above, the reconstruction unit 41 does not perform the reconstruction process after waiting for all the images Wa to We to be prepared, but sequentially performs the reconstruction process using the images sequentially transmitted to the reconstruction unit 41. Therefore, the surgeon does not wait unnecessarily until the rotation imaging is completed and all the two-dimensional images Pa to Pe are generated. That is, the operator can check the information of the three-dimensional image Tw that is gradually reconstructed on the monitor 47 during the execution of the rotational imaging. At the time when the two-dimensional image Pe is generated, the three-dimensional image Tw based on the images Wa to Wd has already been reconstructed. Therefore, since the three-dimensional image Tw based on all of the images Wa to We can be quickly reconstructed by extracting and transmitting the image We, the three-dimensional image Tw is completed almost simultaneously with the completion of the rotation shooting of the imaging system. It becomes. As a result, the time required to complete the three-dimensional image Tw can be further shortened.

Step S6 (Display of short-axis cross-sectional image)
The cross-sectional image generation unit 43 generates a short-axis cross-sectional image using the three-dimensional image Tw. The short-axis cross-sectional image is a cross-sectional view of the three-dimensional image Tw on a plane (GH plane) orthogonal to the major axis direction (J direction) of the stent 59. The J direction can be accurately calculated based on the information of the stent 59 and the marker 63 shown in each two-dimensional image P. In Example 1, since the J direction is parallel to the x direction, the plane perpendicular to the J direction is the yz plane. That is, the cross-sectional image generation unit 43 generates the short-axis cross-sectional image S on the GH plane based on the viewpoint direction indicated by the arrow D (lower right in FIG. 9). As a result, the short-axis cross-sectional image S is an X-ray image including the images of the stent 59 and the blood vessel 65 when the three-dimensional image Tw is viewed from the viewpoint position (not shown) in the direction indicated by the arrow D.

  The short-axis cross-sectional image S is displayed on the monitor 47 in parallel with the cut-out image R as shown in FIG. The cut-out image R is an X-ray image (long-axis cross-sectional image) showing a cross section in the major axis direction for each of the stent 59 and the blood vessel 65, and the short-axis cross-sectional image S is a cross-section in the short axis direction for each of the stent 59 and the blood vessel 65. FIG. That is, the cut-out image R and the short-axis cross-sectional image S are X-ray images that are displayed on planes that are orthogonal to each other. Therefore, the surgeon can confirm three-dimensional information about the position of the stent 59 inside the blood vessel 65 by referring to the cutout image R and the short-axis cross-sectional image S.

  When confirming the three-dimensional information of the stent 59 for another position, as shown in FIG. 10B, the operator operates the input unit 45 to change the position of the attention area W from the position indicated by the dotted line to the solid line. Move to the indicated position. Then, by inputting an instruction to execute reconstruction of a three-dimensional image to the input unit 45, the reconstruction unit 41 generates a three-dimensional image for the attention area W after movement, and the cross-sectional image generation unit 43 indicates by an arrow D. A short-axis cross-sectional image S is generated based on the viewpoint direction. The surgeon can confirm the state in which the branch tube 67 extends from the blood vessel 65 in the z direction by referring to the short-axis cross-sectional image S. Note that the surgeon can also change the attention area W and the viewpoint direction D by operating the input unit 45. In this case, the cross-sectional image generation unit 43 generates the short-axis cross-sectional image S again based on the attention area W and the viewpoint direction D after the change.

  Further, by referring to the combined image in which the cut-out image R and the short-axis cross-sectional image S are paralleled, the surgeon can confirm more accurate information regarding the expanded state of the stent 59. That is, when the stent 59 is expanded as shown in FIG. 10C, the stent 59 is sufficiently expanded in the depth direction (G direction) of the stent 59 only by referring to the cut-out image R which is a long-axis cross-sectional image. It is difficult to confirm whether or not. However, by referring to the short-axis cross-sectional image S, it can be accurately confirmed whether or not the stent 59 is sufficiently expanded and is in contact with the inner wall of the blood vessel 65 in each of the H direction and the G direction.

  Further, the position of each strut 61 can be confirmed by referring to the short-axis cross-sectional image S. Therefore, when the second stent (not shown) is advanced in the direction indicated by the arrow F and is passed between the struts 61 to advance to the branch pipe 67, the second stent is securely inserted between the struts 61 at appropriate positions. Can be passed. Therefore, the treatment of the branch stenosis part by the reverse T-stent method or the like can be performed more precisely. In this way, the surgeon refers to these two X-ray images to advance the IVR procedure, and performs stent placement at an appropriate position with respect to the occluded blood vessel.

<Effects of Configuration of Example 1>
As described above, in the first embodiment, a predetermined region including a part of the stent is set as a region of interest among all the regions of the two-dimensional image P. Then, an image of a part corresponding to the region of interest is extracted from each of the two-dimensional images P generated in one scan, and a three-dimensional image is sequentially reconstructed using each of the extracted images.

  In the conventional radiographic apparatus, the entire image is reconstructed for each of the two-dimensional images generated in one scan, and a three-dimensional image is generated. In this case, the amount of calculation necessary for reconstructing the three-dimensional image becomes enormous and complicated, so that the time required for generating the three-dimensional image becomes very long. As a result, when acquiring a 3D image during an IVR, the surgeon wasted by simply waiting a long time until the 3D image was generated.

  On the other hand, in the radiation imaging apparatus according to the first embodiment, a three-dimensional image is generated using an image corresponding to a region of interest. That is, only a part of the two-dimensional image that needs to be reconstructed as a three-dimensional image is arbitrarily set as a region of interest, and the region of interest is reconstructed. The range of the attention area corresponds to a very small part of the entire two-dimensional image. Therefore, the time required for generating a three-dimensional image can be significantly shortened in the first embodiment compared to the conventional example. As a result, since a three-dimensional image including a necessary area can be quickly acquired, the time required for the IVR can be greatly shortened and the burden on the operator and the subject can be reduced.

  The reconstruction unit 41 performs sequential reconstruction processing using the images of the attention area that are sequentially transmitted. Therefore, the surgeon does not wait indefinitely until the rotation imaging is completed and all the two-dimensional images are generated. That is, the operator can check the information of the three-dimensional image Tw that is gradually reconstructed on the monitor 47 during the execution of the rotational imaging. When the image of the region of interest related to the last two-dimensional image is transmitted, the reconstruction of the three-dimensional image is almost completed, so that the accurate three-dimensional image Tw is obtained almost simultaneously with the completion of the rotation shooting of the imaging system. It will be completed. As a result, the time required to complete the three-dimensional image Tw can be further shortened.

  The cross-sectional image generation unit 43 generates a short-axis cross-sectional image based on the three-dimensional image and the information on the viewpoint direction. The short-axis cross-sectional image is displayed on the monitor in parallel with the cut-out image that is the long-axis cross-sectional image. By referring to the short-axis cross-sectional image, the operator opens the stent 59 not only in the vertical direction (H direction) but also in the depth direction (G direction), and the strut 61 is in close contact with the entire inner wall of the blood vessel 65. Can be confirmed.

  The cut-out image is an X-ray image of a cross section parallel to the x direction, and the short-axis cross-sectional image is an X-ray image of a cross section orthogonal to the x direction. The monitor 47 displays these two X-ray images whose viewpoint directions are orthogonal to each other in parallel. Therefore, the surgeon refers to the two X-ray images displayed in parallel, and knows in detail the position and the open state of the stent 59 in the blood vessel 65 for each of the x direction, the y direction, and the z direction in the three-dimensional space. be able to.

  Therefore, since the stent 59 can be more closely attached to the stenosis portion of the blood vessel 65 in the IVR, it is possible to more reliably avoid the blood vessel 65 from being restenulated after the operation. In addition, when treating a branch vessel by the inverted T-stent method, the operator can confirm the position between the appropriate struts through which the second stent passes through the first stent. Therefore, stent placement can be performed appropriately. As described above, by performing IVR using the radiation imaging apparatus according to the first embodiment, it is possible to quickly and more accurately perform an intravascular treatment that requires three-dimensional image data.

  Next, Embodiment 2 of the present invention will be described with reference to the drawings. About the structure which is common in Example 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  As illustrated in FIG. 11, the radiation imaging apparatus 1 </ b> A according to the second embodiment further includes a virtual endoscope processing unit 69 and a contour display unit 71. The virtual endoscope processing unit 69 is provided in the subsequent stage of the reconstruction unit 41, and performs virtual endoscope processing on the three-dimensional image to generate a virtual endoscope image. Specific contents of the virtual endoscope processing will be described later. The virtual endoscope processing unit 69 corresponds to a virtual endoscope image generating unit in the present invention.

  The contour display unit 71 is connected to the virtual endoscope processing unit 69. The contour display unit 71 detects the contour of the stent by connecting the stent struts shown in the X-ray image in order, and displays the stent contour on the image. As a configuration for detecting the contour of the stent, a differential filter using a Sobel filter as an example may be used. The contour display unit 71 corresponds to the contour display means in the present invention.

<Description of Operation Characteristic of Second Embodiment>
Next, the operation of the radiation imaging apparatus 1A according to the second embodiment will be described. FIG. 4B is a flowchart according to the operation of the second embodiment. The processes from step S1 to step S5 are the same as those in the first embodiment, and thus the description thereof will be omitted. The process of step S6 that is characteristic of the second embodiment will be described. In Example 2, the range of the attention area W is a rectangular area shown in the left diagram of FIG.

  The attention area W can be divided into a plurality of small areas arranged along the long axis of the stent 59 (the right figure in FIG. 12A). Although the number of small areas can be determined arbitrarily, in the second embodiment, the number of small areas is five. Each of the small areas will be described with reference numerals W1 to W5 in order from the direction closer to the arrow D. That is, when the direction of the viewpoint is reversed and the arrow D is changed to the arrow D ', the order of the small areas W1 to W5 is reversed. In this case, the small region closest to the arrow D ′ (the small region W5 in FIG. 12A) is the small region W1.

  Each of the small regions W1 to W5 is a rectangular region extending in the short axis direction H of the stent 59, and the length in the H direction coincides with the length Wh of the attention region W in the H direction. As in Example 1, the length Wh is preferably about 4 mm for diagnosis. The lengths of the small areas W1 to W5 in the J direction can be arbitrarily determined, but the lengths of the small areas W1 to W5 in the J direction are preferably the same. In order to generate a virtual endoscopic image with a high resolution, it is preferable that the length Wj in the J direction of the small regions W1 to W5 is short. That is, the length Wj is more preferably a length corresponding to one pixel of the X-ray image.

Step S6 (Generation of virtual endoscopic image)
In step S5, similarly to the first embodiment, after generating the three-dimensional image Tw in the attention area W, the virtual endoscopic image is generated. The virtual endoscope processing unit 69 uses the three-dimensional image Tw to generate a short-axis cross-sectional image S when the three-dimensional image in each of the small regions W1 to W5 is viewed from the direction indicated by the arrow D. A short-axis cross-sectional image of the small region Wn (n = 1,..., 5) viewed from the arrow D is hereinafter referred to as a short-axis cross-sectional image Sn.

  As an example, the short-axis cross-sectional image S4 is a short-axis cross-sectional image when a three-dimensional image reconstructed with the small region W4 as a region of interest is viewed from the direction indicated by the arrow D. That is, when the viewpoint direction is the arrow D, the short-axis cross-sectional image S4 corresponds to a cross-sectional view taken along the line A-A ′ (FIG. 12A). Thus, the virtual endoscope processing unit 69 generates a plurality of short-axis cross-sectional images S1 to S5 as shown in FIG. 12B according to the number of small regions.

  In addition, the virtual endoscope processing unit 69 displays the blood vessel wall of the blood vessel 65 and the lumen of the blood vessel 65 (inside the blood vessel wall) in each of the short-axis cross-sectional images Sn. As an example, when the region of the blood vessel wall and the region inside the blood vessel can be distinguished and detected based on the CT value (pixel value) in the short-axis cross-sectional image S, the virtual endoscope processing unit 69 determines the blood vessel based on the difference in CT value. The region of the blood vessel wall at 65 is displayed opaquely (see the lower right diagram in FIG. 9, the region indicated by the halftone dots). On the other hand, the lumen area of the blood vessel 65 is displayed transparently. However, in the area of the lumen of the blood vessel 65, the configuration of interest such as the catheter system 53 is displayed opaquely based on the CT value. In the first embodiment, a process of generating a virtual endoscopic image will be described below on the assumption that a blood vessel wall and a lumen can be partitioned and displayed based on a CT value.

  Here, the outline display unit 71 displays the outline of the stent 59 for each of the short-axis cross-sectional images S1 to S5 as appropriate. That is, the outline of the stent 59 is detected by sequentially connecting the struts 61 shown in each of the short-axis cross-sectional images S. The detection of the contour is performed using a differential filter such as a Sobel filter. The detected outline of the stent 59 is displayed as a circular line indicated by a symbol K in the short-axis cross-sectional image S (FIG. 12C, right figure).

  When the stent 59 is sufficiently expanded, the contour K has a large perfect circle shape. When the opening of the stent 59 is insufficient, the contour K is a small circle. If the stent 59 does not expand evenly, the contour K becomes a distorted circle. By referring to the shape of the contour K, the surgeon can confirm whether or not the stent 59 is evenly and sufficiently expanded.

  The virtual endoscope processing unit 69 performs image processing for appropriately enlarging or reducing each of the short-axis cross-sectional images S1 to S5 on which the contour K is displayed according to the distance from the viewpoint position. In other words, the virtual endoscope processing unit 69 is relatively large for the short-axis cross-sectional image S closer to the arrow D and relatively short for the short-axis cross-sectional image S farther from the arrow D. Perform image processing. In the second embodiment, as shown in FIG. 15, image processing is performed so that the short-axis cross-sectional image S1 is the largest among the short-axis cross-sectional images S1 to S5, and the short-axis cross-sectional image S5 is the smallest. The short-axis cross-sectional images S1 to S5 that have been subjected to enlargement or reduction image processing are hereinafter referred to as post-processing cross-sectional images U1 to U5.

  The virtual endoscope processing unit 69 generates a virtual endoscopic image V by superimposing the processed cross-sectional images U1 to U5. In the virtual endoscopic image V, the image of the outline K of the stent 59 is omitted. In the virtual endoscopic image V, the X-ray image is smaller and displayed at the center of the image as the distance from the viewpoint indicated by the arrow D increases. By displaying each short-axis cross-sectional image in a tunnel shape, the virtual endoscopic image V is displayed as if the endoscopic observation of the lumen of the blood vessel 65 and the stent 59 was performed.

  For example, the image of the branch pipe 67 shown in the processed images U4 and U5 is shown as a relatively small image in the virtual endoscopic image V at a position relatively close to the center of the image (FIG. 14). Therefore, the surgeon refers to the virtual endoscopic image V so that the intersection of the blood vessel 65 and the branch pipe 67 is in the position in the x direction and the branch pipe 67 extends downward in the z direction from the intersection. Can be confirmed.

  As shown in FIG. 14, the virtual endoscopic image V is displayed on the monitor 47 in parallel with the cut-out image R. The operator refers to the combined image in which the cut-out image R and the virtual endoscopic image V are arranged in parallel, and advances the IVR technique. The surgeon refers to the cut-out image R to confirm two-dimensional information about the plane parallel to the x direction, and refers to the virtual endoscopic image V to obtain pseudo three-dimensional information about the plane orthogonal to the x direction. I can confirm.

  In addition, the operator can appropriately change the position and size of the attention area W as needed by operating the input unit 45. Then, by inputting an instruction to execute reconstruction of the three-dimensional image to the input unit 45, the reconstruction unit 41 generates a three-dimensional image for the attention area W after movement, and the virtual endoscope processing unit 69 uses the arrow D. A virtual endoscopic image V is generated based on the viewpoint direction indicated by.

  When the position of the region of interest W is moved in the x direction, the X-ray image displayed in the virtual endoscopic image V is changed as if it were moved forward and backward in the blood vessel. When the range of the attention area W is expanded so as to be longer in the x direction, the virtual endoscopic image V becomes an image having a greater depth in the x direction. The surgeon advances the IVR procedure with reference to the combined image, and performs stent placement at an appropriate position with respect to the occluded blood vessel.

  Note that the contour display unit 71 can also display so that the outside and the inside of the contour of the stent 59 indicated by the symbol K can be distinguished. In the short-axis cross-sectional image S, it is often difficult to distinguish the actual blood vessel wall from the inside of the blood vessel wall due to the difference in CT values. Therefore, by displaying the outline of the stent 59 as a boundary line so that the outside and the inside can be distinguished from each other, even if it is difficult to distinguish between the blood vessel wall and the inside of the blood vessel wall based on the CT value, virtual endoscopy The mirror image V can be suitably generated.

  That is, when it is difficult to distinguish between the blood vessel wall and the inside based on the CT value, the surgeon operates the input unit 45 to extract the blood vessel wall based on the CT value and display the distinguished blood vessel from the mode of the stent 59. The mode is changed to a mode for distinguishing and displaying the contour K as a reference. By changing the mode, the contour display unit 71 displays the outside of the contour K of the stent 59 as an area corresponding to the blood vessel wall in an opaque manner for each of the short-axis cross-sectional images S, and the inside of the contour K corresponds to the blood vessel lumen. It is displayed as a transparent area.

  The virtual endoscope processing unit 69 generates a virtual endoscopic image V by superimposing the post-processing cross-sectional images U1 to U5 that are distinguished and displayed with the contour K as a boundary. Generally, in the blood vessel lumen, the stent 59 expands so as to be inscribed in the blood vessel wall of the blood vessel 65. Therefore, a virtual endoscopic image that can distinguish the blood vessel wall and the blood vessel lumen of the blood vessel 65 appropriately by detecting the contour of the stent 59 and further displaying the inside and the outside with the contour K of the stent 59 as a boundary line. V can be generated more reliably.

<Effects of Configuration of Example 2>
In the configuration according to the first embodiment, the cross-sectional image generation unit 43 generates a single short-axis cross-sectional image S based on the three-dimensional image Tw reconstructed with respect to the attention area W. Here, the image generated by the cross-sectional image generation unit 43 corresponds to a short-axis cross-sectional image obtained by viewing the three-dimensional image Tw from the direction indicated by the arrow D, that is, the short-axis cross-sectional image S1. Then, the short-axis cross-sectional image S1 displaying the two-dimensional information in the short-axis direction is displayed in parallel with the cut-out image R.

  On the other hand, in the second embodiment, the virtual endoscope processing unit 69 is based on the three-dimensional image Tw reconstructed with respect to the attention area W, that is, a short-axis cross-sectional image obtained by viewing each small area from the direction indicated by the arrow D, that is, a plurality of images. Short-axis cross-sectional images S1 to S5 are generated. Then, each of the short-axis cross-sectional images S1 to S5 is subjected to image processing at different magnifications and superposed to generate a virtual endoscopic image V. The virtual endoscopic image V displaying the pseudo three-dimensional information in the short axis direction is displayed in parallel with the cut-out image R.

  By referring to the virtual endoscopic image V, the surgeon can also confirm information related to the depth of the long axis direction (J direction) of the lumen of the blood vessel 65 and the stent 59. Therefore, by performing IVR using the radiation imaging apparatus 1A according to the second embodiment, more accurate information can be acquired regarding the three-dimensional position and the open state of the stent 59 inside the blood vessel 65.

  The three-dimensional image Tw used to generate the virtual endoscopic image V is reconstructed based on the image corresponding to the attention area W extracted from each of the two-dimensional images P, as in the first embodiment. Since the range of the attention area is only a part of the entire two-dimensional image, the time required for generating the three-dimensional image can be greatly shortened. As a result, since a virtual endoscopic image can be acquired quickly, the time required for the IVR can be greatly shortened and the burden on the operator and the subject can be reduced.

  The contour display unit 71 detects the contour K of the stent 59 by sequentially connecting the images of the struts 61. Since the contour K is detected using a differential filter such as a Sobel filter, the displayed contour K is an image that accurately reflects the position of the outer contour of the stent 59. By having such a configuration, the position of the contour of the stent 59 can be accurately confirmed even when the stent 59 is expanded and the distance between the struts 61 is widened. Therefore, the surgeon can confirm the three-dimensional position information of the stent 59 in the lumen of the blood vessel 65 more precisely with reference to the virtual endoscopic image V.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In each embodiment described above, the contour display unit 71 may have a configuration connected to the cross-sectional image generation unit 43. In this case, the contour display unit 71 displays the contour K of the stent 59 by connecting the positions of the struts 61 of the stent 59 with a line in the short-axis cross-sectional image S. When the stent 59 is sufficiently expanded, the contour K becomes a large perfect circle as shown in FIG. When the opening of the stent 59 is insufficient, the contour V becomes a small circle.

  And when the stent 59 does not expand equally, as shown in FIG.15 (b), the outline V becomes a distorted circle shape. By having such a configuration, even when the stent 59 is expanded in Example 1 and the interval between the struts 61 is widened, the position of the outline of the stent 59 can be accurately confirmed in the combined image.

  By referring to the shape of the contour K, the surgeon can more accurately confirm whether or not the stent 59 is evenly and sufficiently expanded and is in close contact with the inner wall of the blood vessel 65. Therefore, since the stent 59 can be more closely attached to the stenosis portion of the blood vessel 65 in the IVR, it is possible to more reliably avoid the blood vessel 65 from being restenulated after the operation.

  (2) In each embodiment described above, the extraction of the marker 63, the generation of the integrated image Q, and the generation of the cut-out image R are performed in step S3, but the steps of extracting the marker 63 and generating the integrated image Q are omitted. May be. In this case, the cut-out image R is generated using one of the two-dimensional images P. More preferably, the image used is a two-dimensional image Pe, which is the most recently generated two-dimensional image P. That is, the image cutout unit 35 cuts out the image of the stent 59 and the area near the stent 59 from the two-dimensional image Pe, and appropriately rotates and enlarges the cutout image R. In such a modification, the configuration of the feature point extraction unit 31 and the integration unit 33 can be omitted, so that the configuration of the radiation imaging apparatus can be further simplified.

  (3) In each embodiment described above, when generating the three-dimensional image Tw, the image corresponding to the attention area W is extracted without performing image processing on each of the two-dimensional images Pa to Pe. It is not restricted to such a configuration. That is, as shown in FIG. 16, in the image processing unit 27, an image correction unit 73 may be provided after the attention region display unit 37 and before the attention region extraction unit 39. Each of the two-dimensional images P from which the feature point extraction unit 31 has extracted the marker 63 is transmitted to the image correction unit 73.

  In the configuration according to the modification (3), the image correction unit 73 aligns the stent 59 with respect to each of the two-dimensional images Pa to Pe with respect to each of the two-dimensional images Pa to Pe by image conversion processing such as affine transformation. . Then, the attention area extraction unit 39 extracts an image corresponding to the attention area W from each of the two-dimensional images Pa to Pe after the image conversion processing. The reconstruction unit 41 reconstructs each of the extracted images to generate a three-dimensional image Tw.

  In the case of such a modification, reconstruction is performed based on the two-dimensional image data after image conversion processing even when the stent moves at high speed due to a heartbeat such as cardiovascular intervention (PCI). By doing so, high-quality three-dimensional image data can be acquired in real time. Accordingly, it is possible to quickly acquire a high-quality three-dimensional image that reflects the stent in the cardiovascular vessel during the PCI operation method, which has been impossible to realize until now.

  (4) In each of the above-described embodiments, description has been made using a stent as a device, but a device that is a target for capturing a three-dimensional image is not limited to a stent. Another example of the device is a roller blender used for atherectomy. In this case, by referring to the cut-out image and the short-axis cross-sectional image (or virtual endoscopic image) on the single monitor 47, the position of the roller blader can be appropriately controlled. Therefore, the surgeon can cut atheroma and calcified blood vessel wall more reliably. Accordingly, it is possible to reliably avoid the roller blader from cutting the normal blood vessel wall by mistake, thereby reducing the burden on the subject.

  (5) In each of the above-described embodiments, the body axis direction of the subject M and the major axis direction of the stent 59 are parallel, and the C-arm 9 is about the body axis direction (x direction) of the subject M. Although the case of rotating has been described as an example, the direction of the rotation axis of the C-arm 9 is not limited to the axial direction parallel to the x direction. That is, the direction of the rotation axis of the C-arm 9 may be appropriately changed according to the major axis direction of the stent 59.

  As an example, when the major axis direction J of the stent 59 is different from the body axis direction of the subject M, the surgeon operates the input unit 45 to generate the two-dimensional image P in step S <b> 2. Change the rotation axis direction. Then, the rotation axis direction of the C-arm 9 is adjusted so as to be substantially parallel to the major axis direction J of the stent 59. In this case, the imaging system including the X-ray tube 5 and the X-ray detector 7 moves along an arc orbit that rotates around an axis in a predetermined direction substantially parallel to the J direction. As a result, in each of the two-dimensional images P, an X-ray image in the major axis direction of the stent 59 is suitably displayed. In this case, the short-axis cross-sectional image S is generated on a plane orthogonal to the rotational axis direction of the C-arm 9 after the change.

  (6) In each of the above-described embodiments, the body axis direction of the subject M and the major axis direction of the stent 59 are parallel, and the short-axis cross-sectional image S is generated on the yz plane orthogonal to the body axis direction of the subject M. However, the cross section in which the short-axis cross-sectional image S is generated is not limited to a plane orthogonal to the x direction. That is, the direction of the plane in which the short-axis cross-sectional image S is generated may be appropriately changed according to the long-axis direction of the stent 59. In this case, the short-axis cross-sectional image S is generated on a plane different from the plane on which the cutout image R is generated.

  In the configuration according to the modified example (6), the image processing unit 27 can calculate the J direction, which is the major axis direction of the stent, based on the information of the stent 59 and the marker 63 that appear in each of the two-dimensional images P. Based on the calculated information on the major axis direction of the stent 63, the cross-sectional image generation unit 43 generates a short-axis cross-sectional image for a plane orthogonal to the J direction.

  (7) In each of the embodiments described above, after setting the attention area W in step S4, the three-dimensional image Tw is reconstructed in step S5. However, the timing for setting the attention area W may be changed as appropriate. . That is, as an example, the attention area W may be arbitrarily set after the order of step S4 and step S5 is switched and the three-dimensional image Tw is reconstructed. When the surgeon has not set the attention area W when reconstructing the three-dimensional image Tw, the reconstruction unit 41 uses the three-dimensional image for the attention area in the default state (for example, a predetermined area between the markers 63a and 63b). Reconstruct Tw. Then, after changing the attention area W, a three-dimensional image Tw and a short-axis cross-sectional image S are generated for the attention area W after the change.

  (8) In the above-described second embodiment, the blood vessel wall of the blood vessel 65 or the contour K of the stent 59 is automatically detected as a boundary line, and the outside and inside of the boundary line are automatically displayed as a partition in the virtual endoscopic image. However, the present invention is not limited to a configuration that automatically detects a boundary line that is a reference for partition display. That is, the configuration may be such that the boundary line can be manually set in the virtual endoscopic image.

  In the second embodiment, the case where the blood vessel wall of the blood vessel 65 and the contour of the stent 59 can be automatically detected as a boundary line based on the CT value is described. However, in an actual medical site, it may be difficult to clearly extract the blood vessel wall of the blood vessel 65 or the outline of the stent 59 as a boundary line based on the difference in CT value. When it is difficult to automatically extract a clear boundary line in the configuration according to the modification (8), the surgeon refers to a virtual endoscopic image or the like displayed on the monitor 47, and performs manual operation using the input unit 45 or the like. A substantially circular boundary line having a predetermined diameter is set.

  The virtual endoscope processing unit 69 displays the virtual endoscope image V so that the outside and the inside of the boundary set by manual operation can be distinguished. As an example, the outside of the boundary line is opaquely displayed as a region corresponding to the blood vessel wall, and the inside of the boundary line is transparently displayed as a region corresponding to the blood vessel lumen. In this way, by making it possible to manually set the boundary line for distinguishing and displaying the virtual endoscopic image, the region corresponding to the blood vessel wall and the region corresponding to the blood vessel lumen regardless of the quality of the three-dimensional image Tw A high-quality virtual endoscopic image can be realized.

  (9) In Example 2 described above, a contrast agent may be used in order to display the blood vessel wall and the blood vessel lumen more easily and clearly. That is, in the virtual endoscopic image V, when it is difficult to distinguish the blood vessel wall and the blood vessel lumen of the blood vessel 65 based on the difference in CT value, the contrast agent is injected into the blood vessel 65 through the catheter 55. In the non-contrast state, the CT value difference is small between the blood vessel wall of the blood vessel 65 and the blood vessel lumen. However, in the contrast state, the contrast agent fills the blood vessel lumen, so that the difference in CT value between the blood vessel wall of the blood vessel 65 and the blood vessel lumen becomes large. As a result, the division display of the blood vessel wall and the blood vessel lumen based on the CT value is very facilitated by the injection of the contrast agent.

DESCRIPTION OF SYMBOLS 1 ... Radiography apparatus 3 ... Top plate 5 ... X-ray tube (radiation source)
7 ... X-ray detector (radiation detection means)
19 ... X-ray irradiation control unit (radiation irradiation control means)
23 ... Arm drive control unit (imaging system moving means)
25: Imaging position detection unit 29 ... Image generation unit (image generation unit)
31 ... Feature point extraction unit (feature point extraction means, reference point extraction means)
33 ... Integration unit (integration means)
35 ... Image cutout unit (image cutout means)
37 ... Attention area display section (attention area display means)
39: Attention area extraction unit (attention area extraction means)
41 ... Reconstruction unit (reconstruction means)
43... Sectional image generating unit (short axis sectional image generating means)
59 ... Stent (device)
63 ... Marker (feature point, reference point)
69... Virtual endoscope processing unit (virtual endoscope image generating means)
71 ... contour display section (contour display means)
73 Image correction unit (image correction means)

Claims (9)

A radiation source for irradiating the subject with radiation;
Radiation detecting means for detecting the radiation transmitted through the subject;
An imaging system moving unit configured to move an imaging system including the radiation source and the radiation detection unit along a predetermined trajectory with respect to the subject;
A radiation irradiation control means for controlling the radiation source to repeat radiation irradiation while the imaging system moves along a predetermined trajectory with respect to the subject;
Image generating means for generating a two-dimensional image of a region including a device inserted into the body of the subject, based on a radiation detection signal output by the radiation detecting means each time the radiation source performs radiation irradiation;
Attention area extraction means for extracting a predetermined area including a part of the device as an attention area from each of the two-dimensional images generated by the image generation means;
Reconstruction for reconstructing a three-dimensional image of the region of interest based on each of the images corresponding to the region of interest extracted by the region of interest extraction unit from each of the series of two-dimensional images generated by the image generation unit A radiographic apparatus comprising: means. The radiographic apparatus according to claim 1,
Image cutout means for cutting out a part of the device from the two-dimensional image and generating a cutout image;
Based on the three-dimensional image, a short-axis cross-sectional image generating unit that generates a radiographic image of a cross-section orthogonal to the long-axis direction of the device as a short-axis cross-sectional image;
A radiation imaging apparatus comprising: an image display unit that displays the cut-out image and the short-axis cross-sectional image in parallel. The radiation imaging apparatus according to claim 2,
Feature point extracting means for extracting feature points from the two-dimensional image;
An integration unit that generates an integrated image by superimposing a plurality of the two-dimensional images on the basis of the feature points extracted by the feature point extraction unit;
The radiographic apparatus that generates the cutout image by cutting out the part of the device from the integrated image. In the radiographic apparatus of Claim 2 or Claim 3,
A radiation imaging apparatus comprising attention area display means for displaying a range of the attention area with respect to the clipped image displayed on the image display means. The radiation imaging apparatus according to claim 4,
A region of interest setting means for arbitrarily setting the position and size of the region of interest displayed in the clipped image;
The attention area extraction unit is a radiation imaging apparatus that extracts an image corresponding to the attention area from each of the two-dimensional images based on the attention area set by the attention area setting section. The radiographic apparatus according to any one of claims 2 to 5,
The size of each of the plurality of short-axis cross-sectional images generated based on the three-dimensional image is corrected so as to become larger as the viewpoint is closer to the short-axis cross-sectional image, and the corrected short-axis cross-sectional image is corrected. A radiography apparatus comprising virtual endoscopic image generation means for generating a virtual endoscopic image of the region of interest by superimposing each of the above. The radiographic apparatus according to claim 6,
The image display means is a radiation imaging apparatus that displays the cut-out image and the virtual endoscopic image in parallel. The radiographic apparatus according to any one of claims 2 to 7,
A radiation imaging apparatus comprising contour display means for displaying a contour of the device reflected in the short-axis cross-sectional image. The radiographic apparatus according to any one of claims 1 to 8,
Reference point extraction means for extracting a reference point from the two-dimensional image;
Image correction means for correcting each of the series of two-dimensional images based on the reference points so that the positions of the devices reflected in the two-dimensional image are the same;
The attention area extraction unit is a radiographic apparatus that extracts an image of a portion corresponding to the attention area from a series of the two-dimensional images corrected by the image correction unit.

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