X-ray fluoroscopic imaging apparatus and image processing device

Abstract

To provide virtual collimation technology for displaying the most recent fluoroscopic image along with the current collimator position which, even in the presence of a misalignment between the fluoroscopic image and the current collimated field of view, realizes display of an image compensated for the misalignment.SOLUTION: An image processing device generates fluoroscopic images for an X-ray fluoroscopic imaging apparatus. In a virtual collimation mode, if the field of view of a movable collimator is larger than that of the most recently generated fluoroscopic image, and fluoroscopic images stored in a past image memory include an image of an outer region of the most recent fluoroscopic image, then the device supplements the outer region of the most recent fluoroscopic image using the fluoroscopic images stored in the past image memory.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an X-ray fluoroscopic imaging apparatus capable of generating a fluoroscopic image. [Background technology]

[0002] In X-ray imaging devices capable of capturing fluoroscopic images (moving images) and X-ray images (still images), there is a technology (virtual collimation) that freezes the previous fluoroscopic image (LIH (Last Image Hold) image) and displays it on the image display device to determine the shooting range (aperture position) of the X-ray image. This technology allows the operator to adjust the aperture position while viewing the previous image of the subject.

[0003] Patent Document 1 discloses a technique for reducing radiation exposure of a subject by installing an optical camera in an X-ray imaging device and displaying a camera image on an image display device instead of an LIH image.

[0004] Meanwhile, Patent Document 2 discloses a technique for displaying an X-ray image taken before catheter insertion as a reference image alongside a fluoroscopic image in interventional radiology (IVR), in which a catheter is inserted into a blood vessel while viewing a fluoroscopic image. The reference image is displayed by enlarging or reducing it so that it has the same field of view (region of interest) as the current fluoroscopic image. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-63839 A [Patent Document 2] JP 2007-159599 A Summary of the Invention [Problem to be solved by the invention]

[0006] In virtual collimation technology that displays the current aperture position on the LIH image, if the field of view of the current aperture is wider than the field of view of the LIH image, no images can be displayed around the LIH image.

[0007] The technology of Patent Document 1 uses camera images, so it can acquire and display camera images outside the field of view of the LIH image, but it requires the installation of an optical camera in the X-ray imaging device, and it is also necessary to align the camera image with the fluoroscopic image, which makes the device configuration complicated. Also, since the inside of the subject cannot be seen in the camera image, it may be difficult for the operator to determine the imaging range for X-ray imaging from the camera image.

[0008] On the other hand, the technology of Patent Document 2 requires the preparation of a reference X-ray image taken over a wide area before the catheter is inserted, and changes in the subject caused by catheter insertion, stent placement, etc. are not reflected in the reference X-ray image.

[0009] The object of the present invention is to display an image that compensates for the misalignment in a virtual collimation technique that displays the immediately preceding fluoroscopic image (LIH (Last Image Hold) image) and the current aperture position, even if the current aperture field of view is misaligned with respect to the LIH image. [Means for solving the problem]

[0010] In order to achieve the above object, according to the present invention, there is provided an X-ray fluoroscopy imaging device having a tabletop on which a subject is placed, an X-ray tube which irradiates X-rays onto the subject, a movable aperture which adjusts the irradiation range of the X-rays irradiated from the X-ray tube, an X-ray detector which detects the X-rays which have passed through the subject, an image processing device which is capable of generating fluoroscopic images and still X-ray images from the output of the X-ray detector, a display image memory which stores each time the image processing device generates a fluoroscopic image at a predetermined rate as the current final fluoroscopic image and holds it until the next fluoroscopic image is generated and displays it on a connected image display device, a past image memory which stores fluoroscopic images generated by the image processing device prior to the current time, and an image complement device. The image processing device includes a fluoroscopy mode for generating a fluoroscopy image, an imaging mode for generating an X-ray image, and a virtual collimation mode for displaying on the image display device a final fluoroscopy image held in the display image memory after the fluoroscopy mode and before the imaging mode is performed, superimposed with a mark indicating the position of the movable aperture. In a fluoroscopy mode, when the field of view of a currently generated fluoroscopy image is larger in size or displaced in position compared with the field of view of a fluoroscopy image already stored in the past image memory, the image processing device updates the currently generated fluoroscopy image by storing it in the past image memory. In a virtual collimation mode, when the field of view of the movable aperture is larger than the final perspective image stored in the display image memory and the perspective image stored in the past image memory includes an image of an area outside the final perspective image, the image complementing device generates an image in which the outer area of ​​the final perspective image is complemented by the perspective image stored in the past image memory. Effect of the Invention

[0011] According to the present invention, even if the current aperture field of view is misaligned with respect to the LIH image, an image can be displayed in which the misaligned area is complemented with the saved final fluoroscopic image, allowing the operator to adjust the aperture position on the image that is closest to the current state of the subject. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing the overall configuration of an X-ray fluoroscopic imaging apparatus according to a first embodiment of the present invention. [Diagram 2] 4 is a flowchart showing the operation of the X-ray fluoroscopic imaging apparatus of the first embodiment. [Diagram 3] 3(a) to 3(c) are diagrams illustrating the operation of the X-ray fluoroscopic imaging apparatus of the first embodiment. [Figure 4] 3(a) to 3(e) are diagrams illustrating the operation of the X-ray fluoroscopic imaging apparatus of the first embodiment. [Diagram 5] 3(a) to 3(e) are diagrams illustrating the operation of the X-ray fluoroscopic imaging apparatus of the first embodiment. [Figure 6] FIG. 11 is a block diagram showing the overall configuration of an X-ray fluoroscopic imaging apparatus according to a second embodiment of the present invention. [Figure 7] 10 is a flowchart showing the operation of the X-ray fluoroscopic imaging apparatus of the second embodiment. [Figure 8] 10(a) to 10(i) are diagrams illustrating the operation of the X-ray fluoroscopic imaging apparatus of the second embodiment. [Figure 9] 10(a) to 10(c) are diagrams illustrating the operation of the X-ray fluoroscopic imaging apparatus of the second embodiment. [Figure 10] FIG. 11 is a block diagram showing the overall configuration of an X-ray fluoroscopic imaging apparatus according to a third embodiment of the present invention. [Figure 11] 11 is a flowchart showing the operation of the X-ray fluoroscopic imaging apparatus of the third embodiment. [Figure 12] 13(a) and 13(b) are diagrams for explaining the operation of the X-ray fluoroscopic imaging apparatus of the third embodiment. [Figure 13] 13A to 13C are diagrams for explaining a complementation screen of the X-ray fluoroscopic imaging apparatus according to the fourth embodiment. [Figure 14] 10 is a flowchart showing an example of the operation of the X-ray fluoroscopic imaging apparatus of the fourth embodiment. [Figure 15] 10 is a flowchart showing an example of the operation of the X-ray fluoroscopic imaging apparatus of the fourth embodiment. [Figure 16] 10 is a flowchart showing an example of the operation of the X-ray fluoroscopic imaging apparatus of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an X-ray fluoroscopic imaging apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0014] <<Embodiment 1>> The X-ray fluoroscopic imaging apparatus of the first embodiment will be described with reference to Fig. 1 to Fig. 5. Fig. 1 is a block diagram showing the overall configuration of the X-ray fluoroscopic imaging apparatus of the first embodiment, and Fig. 2 is a flowchart showing the operation of the X-ray fluoroscopic imaging apparatus. Figs. 3 to 5 are diagrams for explaining the operation.

[0015] The X-ray fluoroscopic imaging device includes a tabletop 12 on which a subject 25 is placed, an X-ray tube 10 that irradiates the subject with X-rays, a movable aperture 13, an X-ray detector 11 that detects X-rays that have passed through the subject, an image processing device 20 that can generate fluoroscopic images and still X-ray images from the output of the X-ray detector 11, an image complementing device 21, a display image memory 22, and a past image memory 31. The movable aperture 13 includes a plurality of aperture blades 13a, and adjusts the irradiation range of the X-rays irradiated from the X-ray tube 10 onto the subject 25. A high voltage generator 14 that supplies a tube current and a tube voltage is connected to the X-ray tube 10. A system control device 16 is connected to the high voltage generator 14 and the movable aperture 13, and controls the operations of the high voltage generator 14 and the movable aperture 13. An operation device 15 is connected to the system control device, and an operator can set the field size of the movable aperture 13 to a desired size or the like using the operation device 15.

[0016] The top 12 also has a built-in mechanism for moving the top 12 at least within its main plane. A mechanism control device 17 is connected to the mechanism and controls the mechanism. By moving the top 12 within its main plane, the mechanism control device 17 can relatively displace the positional relationship between the X-ray tube 10 and the top 12, and relatively move the field of view of the movable aperture 13 on the subject. The mechanism control device 17 may also move an arm (not shown) supporting the X-ray tube 10 in a direction parallel to the main plane of the top 12.

[0017] In this embodiment, the relative positions of the tabletop 12 and the X-ray tube 10 are not changed from the time fluoroscopy is being performed until X-ray imaging is performed.

[0018] Every time the image processing device 20 generates a fluoroscopic image at a predetermined rate, the generated fluoroscopic image is stored in the display image memory 22 as a current final fluoroscopic image 34. The stored final fluoroscopic image 34 is held in the display image memory 22 until the next fluoroscopic image is generated. In other words, the final fluoroscopic image 34 is an LIH (Last Image Hold) image. The final fluoroscopic image (LIH image) 34 stored in the display image memory 22 is displayed on the connected image display device 23 (see FIG. 3(a)).

[0019] On the other hand, the previous image memory 31 stores the fluoroscopic images generated by the image processing device 20 before the current time.

[0020] The image processing device 20 can execute a fluoroscopy mode, an imaging mode, and a virtual collimation mode. In the fluoroscopy mode, the X-ray tube 10 irradiates X-rays at a predetermined imaging rate under the control of the system control device 16. The image processing device 20 generates a fluoroscopy image at a predetermined rate from the output of the X-ray detector 11. In the imaging mode, the X-ray tube 10 irradiates X-rays only once under the control of the system control device 16. The amount of X-rays irradiated in the imaging mode is generally greater than the amount of X-rays irradiated in the fluoroscopy mode. The image processing device 20 generates a still X-ray image from the output of the X-ray detector 11.

[0021] The virtual collimation mode is a mode performed after the fluoroscopy mode and before the imaging mode, in which the final fluoroscopy image (LIH image) 34 stored in the display image memory 22 is superimposed on a mark (dotted line 36 in this case) indicating the position (field of view) of the aperture blades 13a of the movable aperture 13 and displayed on the image display device 23 as shown in Figures 3(b) and (c).

[0022] In the virtual collimation mode, by viewing the final fluoroscopic image (LIH image) 34 and the image of the dotted line 36 displayed on the image display device 23 as shown in Fig. 3(c), the operator can grasp the field of view of the variable diaphragm 13 on the final fluoroscopic image (LIH image) 34 by the dotted line 36. Therefore, while viewing the image of Fig. 3(c), the operator can adjust the field of view of the movable diaphragm 13 to a desired range of the subject 25 in the final fluoroscopic image (LIH image) 34. After the adjustment, by executing the imaging mode, an X-ray image of the field of the movable diaphragm 13 can be captured while preventing unnecessary radiation exposure by the movable diaphragm 13.

[0023] 3(b), when the size of the field of view of the movable diaphragm 13 is larger than the field of view of the final perspective image (LIH image) 34, it is not possible to grasp the shape of the subject 25 outside the final perspective image (LIH image) 34. To solve this problem, in this embodiment 1, the image processing device 20 and the image complementing device 21 operate as follows.

[0024] That is, while the image processing device 20 is executing the fluoroscopy mode, if the field of view of the currently generated fluoroscopy image is larger in size than the field of view of the fluoroscopy image already stored in the previous image memory 31, the image processing device 20 stores the currently generated fluoroscopy image in the previous image memory 31. In this way, the previous image memory 31 is updated.

[0025] In a virtual collimation mode performed after the perspective mode, when the field of view of the movable diaphragm 13 is larger than the final perspective image (LIH image) 34 stored in the display image memory and the perspective image stored in the past image memory 31 includes an image of an area 33 outside the final perspective image (LIH image) 34, the image complementing device 21 generates an image in which the area 33 outside the final perspective image (LIH image) 34 is complemented with the perspective image stored in the past image memory 31. The image complementing device 21 causes the image display device 23 to display the complemented image.

[0026] In the first embodiment, in order to store in the past image memory 31 a fluoroscopic image that is as close as possible to the time of generation of the final fluoroscopic image (LIH image) 34 and has a large field of view size, the past image memory 31 is configured to include a first past image memory 18 and a second past image memory 19 (see FIG. 1). The first past image memory 18 stores an image of a maximum field of view size 41 of the movable diaphragm 13 (see FIGS. 4(a), 5(a), and (b)). The second past image memory 19 stores an image of a size equal to or larger than a predetermined second size 42 that is smaller than the maximum field of view size 41, but smaller than the maximum field of view size (see FIGS. 4(a), 5(a), and (c)).

[0027] In the perspective mode, when the field of view size 44 of the currently generated perspective image is larger than the second size 42 and smaller than the maximum field of view size 41 of the movable aperture 13, the image processing device 20 stores the currently generated perspective image in the second past image memory 19 (Figure 4(b)).

[0028] On the other hand, when the field of view size 44 of the currently generated perspective image is the maximum field of view size 41 of the movable diaphragm 13, the image processing device 20 stores it in the first past image memory 18 (FIG. 4(b)).

[0029] If even one side of the field of view size 44 of the perspective image is smaller than the second size 42, the image processing device 20 does not store the image in either the first past image memory 18 or the second past image memory 19 (see FIGS. 4(d) and (e)).

[0030] In the virtual collimation mode, when the field of view of the movable aperture 13 is larger than the final perspective image (LIH image) 34 in the display image memory 22 and smaller than the second size 42 (Figure 5(e)), the image complement device 21 selects the perspective image generated more recently from the perspective image stored in the first past image memory 18 (Figure 5(b)) and the perspective image stored in the second past image memory 19 (Figure 5(c)), and uses this to complement the outer area of ​​the final perspective image (LIH image) 34.

[0031] On the other hand, in the virtual collimation mode, when the field of view of the movable aperture 13 is larger than the final perspective image (LIH image) 34 and larger than the second size 42 (Figure 5(d)), the image completion device 21 complements the outer area of ​​the final perspective image (LIH image) 34 with the perspective image (Figure 5(b)) stored in the first past image memory 18.

[0032] In this way, in the X-ray fluoroscope of the first embodiment, even if the field of view of the current movable diaphragm 13 is set larger than the final fluoroscopic image (LIH image) 34 as shown in Fig. 3(b) when performing virtual collimation, the outer region of the final fluoroscopic image (LIH image) 34 can be complemented and displayed using the previous fluoroscopic image. Therefore, the operator can grasp the shape of the subject 25 even in the complemented region 33, and can easily set the field of view of the movable diaphragm 13.

[0033] Furthermore, the latest fluoroscopic image can be selected and used for the complement from either the first past image memory 18 or the second past image memory 19 depending on the size, so that it is possible to display an image that reflects changes in the subject 25 during fluoroscopy.

[0034] A more detailed explanation will be given below with reference to the flow in FIG.

[0035] The system control device 16, the image processing device 20, and the image completion device 21 are configured by a computer or the like equipped with a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) and a memory. The CPU or the like reads and executes a program stored in the memory (storage unit), thereby realizing the functions of the system control device 16, the image processing device 20, and the image completion device 21.

[0036] The image processing device 20 and the image completion device 21 can be configured in part or in whole by hardware. For example, a circuit design can be performed to realize the functions of the system control device 16, the image processing device 20, and the image completion device 21 using a custom IC such as an ASIC (Application Specific Integrated Circuit) or a programmable IC such as an FPGA (Field-Programmable Gate Array).

[0037] In the following flow, steps 101 to 108 are in the fluoroscopy mode, steps 109 to 120 are in the virtual collimation mode, and steps 121 to 123 are in the imaging mode.

[0038] The second size 42 shown in FIG. 4(a) and FIG. 5(a) is determined in advance based on a ratio (for example, 60%) of the movable diaphragm 13 to the maximum field size 41.

[0039] In the following flow, it is assumed that the relative positional relationship between the tabletop 12 and the X-ray tube 10 does not change, and that the center of the field of view of the movable diaphragm 21 does not move.

[0040] (Step 101) When the operator adjusts the adjustable aperture 13 using the operation device 15 and instructs the system controller 16 to start fluoroscopy, the system controller 16 supplies a predetermined tube voltage and tube current for fluoroscopy from the high voltage generator 14 to the X-ray tube at a predetermined interval (rate (e.g., 20 times / s)). As a result, X-rays are irradiated from the X-ray tube 10 to the subject 25 at the above-mentioned rate. The X-rays that have passed through the subject 25 are detected by the X-ray detector 11.

[0041] (Step 102) The image processing device 20 takes in data from the X-ray detector 11, generates an image from the data, and generates a fluoroscopic image by removing the image of the movable diaphragm 13 from the image, and stores the image in the display image memory 22. In this way, the latest fluoroscopic image (last fluoroscopic image 34) is always stored in the display image memory 22, and LIH (Last Image Hold) is realized.

[0042] (Step 103) The image processing device 20 causes the image display device 23 to display the latest fluoroscopic image (last fluoroscopic image (LIH image) 34) in the display image memory 22 (see FIG. 3(a)).

[0043] (Step 104) The image processor 20 determines whether the field of view size 44 of the perspective image in the display image memory 22 is larger than a second size 42 that is determined in advance.

[0044] When the field of view size 44 of the perspective image is larger than the second size 42 as in FIGS. 4(b) and 4(c), the image processing device 20 proceeds to step 105 to store the image in either the first or second past image memory 18, 19.

[0045] On the other hand, when the field of view size 44 of the perspective image is smaller than the second size 42 as in FIGS. 4(d) and 4(e), the image is not stored in the first and second past image memories 18 and 19, and the image processing device 20 proceeds to step .

[0046] (Step 105) Next, the image processing device 20 determines whether the field size 44 of the perspective image matches the maximum field size 41 of the movable diaphragm 13 .

[0047] When the field of view size 44 of the perspective image matches the maximum field of view size 41 as in FIG. 4( a ), the image processing device 20 proceeds to step 106 in order to store the image in the first previous image memory 18 .

[0048] On the other hand, when the field of view size 44 of the perspective image is smaller than the maximum field of view size 41 as shown in FIG. 4(b), the image processing device 20 proceeds to step 107 to store the image in the second past image memory 19.

[0049] (Step 106) The image processing device 20 copies the perspective image in the display image memory 22 to the first past image memory 18 (see FIG. 4(b)).

[0050] (Step 107) The image processing device 20 copies the perspective image in the display image memory 22 to the second past image memory 19 (see FIG. 4(c)).

[0051] (Step 108) The image processing device 20 determines from the control signal of the system control device 16 whether the operator has instructed to end the fluoroscopy, and if the operator has not instructed to end the fluoroscopy, returns to step 102 and generates the next fluoroscopy image.

[0052] On the other hand, if an instruction to end fluoroscopy has been issued, the image processing device 20 proceeds to step 109 .

[0053] (Step 109) In step 109, in order to execute the virtual collimation mode, if the operator has instructed the system control device 16 to change the position (field of view) of the movable aperture 13 from the control device 15, the system control device 16 controls the movable aperture 13 to execute the change.

[0054] (Step 110) The image complement device 21 receives the position of the movable aperture 13 from the system controller 16 and calculates the field of view (region of interest). (Step 111) The image completion device 21 confirms, via the system control device 16, that the relative positions of the tabletop 12 and the X-ray tube 10 (imaging system) have not changed between the time when the fluoroscopic image (final fluoroscopic image (LIH image) 34) in the display image memory 22 was generated and the current time.

[0055] (Step 112) The image completion device 21 determines whether the field of view (region of interest) of the movable diaphragm 13 calculated in step 110 is larger than the final perspective image (LIH image) 34 in the display image memory 22 .

[0056] If the field of view (region of interest) of the movable diaphragm 13 is equal to or smaller than the size of the final perspective image (LIH image) 34 in the display image memory 22 (see FIG. 3( c )), no interpolation is necessary, so the image interpolation device 21 proceeds to step 113 .

[0057] On the other hand, if the field of view (region of interest) of the movable aperture 13 is larger than the final perspective image (LIH image) 34 in the display image memory 22 (see FIG. 3(b)), the image complement device 21 proceeds to step 114 to generate a complemented image of the complement region 33.

[0058] (Step 113) The image complementing device 21 generates an image in which a mark (dotted line 36) indicating the current position of the field of view of the movable diaphragm 13 is superimposed on the final perspective image (LIH image) 34 as shown in FIG. 3(c), and proceeds to step 120.

[0059] (Step 114) In step 114, the image complement device 21 reduces and displays the final perspective image (LIH image) 34 displayed on the image display device 23 so that the field of view (region of interest) of the movable diaphragm 13 is displayed on the full screen of the image display device 23 (FIG. 3(b)). As a result, a complement region 33 is displayed around the final perspective image (LIH image) 34.

[0060] (Steps 115-116) Furthermore, in order to select a past perspective image to be used for complementing the complement region 33, the image complement device 21 determines whether the field of view (region of interest) of the movable diaphragm 13 is larger than the second size 42 (step 115), and if it is larger, proceeds to step 116 to select the perspective image in the first past image memory 18 as an image to be used for complement. The image complement device 21 cuts out an image of a region that is outside the field of view 32 of the final perspective image (LIH image) 34 but inside the field of view of the movable diaphragm 13 from the selected perspective image in the first past image memory 18, and places it in the complement region 33 outside the final perspective image (LIH image) 34. In this way, a complemented image is generated. (Steps 117~118).

[0061] On the other hand, if the field of view (region of interest) of the movable aperture 13 is smaller than the second size 42, from the standpoint of size, either the perspective image in the first past image memory 18 or the perspective image in the second past image memory 19 can be used for complementation, so the process proceeds to step 117 to select the newer one.

[0062] In step 117, if the fluoroscopic image in the first past image memory 18 is newer, the process proceeds to step 116, and if the fluoroscopic image in the second past image memory 19 is newer, the process proceeds to step 118.

[0063] In step 118, the image complement device 21 cuts out an image of a region that is outside the field of view 32 of the final perspective image (LIH image) 34 and inside the field of view of the movable diaphragm 13 from the selected perspective image in the second past image memory 19, and places the image in a complementation region 33 outside the final perspective image (LIH image) 34. In this way, a complemented image is generated.

[0064] (Step 119) The image complement device 21 displays the position of the adjustable aperture by surrounding the outside of the complemented image with a dotted line 36 as shown in FIG. 3( b ), and then proceeds to step 120 .

[0065] (Step 120) The image completion device 21 displays the image generated in step 113 or step 119 on the image display device 23 .

[0066] (Steps 121-122) Next, the system controller 16 determines whether or not an instruction for X-ray photography has been issued by the operator, and if so, proceeds to step 122 .

[0067] In step 122, the system control device 16 supplies a predetermined tube voltage and tube current for X-ray imaging from the high voltage generator 14 to the X-ray tube once. As a result, X-rays are irradiated from the X-ray tube 10 to the subject 25, and the X-rays that have passed through the subject 25 are detected by the X-ray detector 11. The image processing device 20 generates an X-ray image within the field of view (dotted line 36) of the aperture 13 from the X-ray detector 11.

[0068] (Step 123) When the system controller 16 receives an instruction to resume fluoroscopy from the operator, the process proceeds to step 101 and plays back the fluoroscopy. When there is no instruction to resume fluoroscopy, the process ends.

[0069] By operating the X-ray fluoroscopic imaging device according to the above flow, the periphery of the final fluoroscopic image can be complemented using the most recent past image of the minimum necessary size, making it easy to perform virtual collimation.

[0070] In this embodiment, the virtual collimation in steps 109 to 120 is performed to prepare for the imaging mode, but virtual collimation may be performed to change the size of the aperture during the fluoroscopy mode. In that case, it is of course possible to remove steps 121 and 122 from the flow in FIG. 2 and make it a flow dedicated to fluoroscopy.

[0071] In this embodiment, the number of previous image memories 31 is not limited to one or two as described above, but may be three or more. The greater the number of previous image memories 31, the higher the probability that the latest image can be used at the time of complementation.

[0072] <<Embodiment 2>> The X-ray imaging apparatus of the second embodiment will be used for explanation.

[0073] In the first embodiment, it is assumed that the relative positional relationship between the tabletop 12 and the X-ray tube 10 is not changed, and the center of the field of view of the movable diaphragm 13 is not moved either. As a result, in the first embodiment, complementation is performed when the size of the field of view of the movable diaphragm 13 differs from that of the final fluoroscopic image (LIH image) 34. In the second embodiment, fluoroscopy is performed while moving the center of the field of view of the movable diaphragm 13 by displacing the position of the diaphragm blades 13a of the movable diaphragm 13 or by relatively displacing the positional relationship between the tabletop 12 and the X-ray tube 10.

[0074] In the second embodiment, if the position of the field of view of the currently generated fluoroscopic image is shifted compared with the field of view of the fluoroscopic image already stored in the previous image memory 31, the currently generated fluoroscopic image is updated by storing it in the previous image memory 31.

[0075] In the virtual collimation mode, when the field of view of the movable aperture 13 is larger than the final perspective image (LIH image) 34 stored in the display image memory 22, and the perspective image stored in the past image memory 31 includes an image of the area outside the final perspective image (LIH image) 34, an image is generated in which the outer area of ​​the perspective image 34 is complemented by the perspective image stored in the past image memory 31 (LIH image).

[0076] Specific settings will be made below with reference to Fig. 6 to Fig. 9. Fig. 6 is a block diagram showing the overall configuration of the X-ray fluoroscopic imaging apparatus of the first embodiment, and Fig. 7 is a flowchart showing the operation. Figs. 8 and 9 are diagrams for explaining the operation.

[0077] 6, the configuration is the same as that of the X-ray fluoroscopic imaging apparatus of the second embodiment, but differs from that of the first embodiment in that a map image memory 24 is arranged in the past image memory 31. Other configurations of the X-ray fluoroscopic imaging apparatus of the second embodiment are the same as those of the apparatus of the first embodiment, and therefore description thereof will be omitted.

[0078] Specifically, in the fluoroscopy mode, the image processing device 20 sets an area 81 for the subject 25 on the tabletop 12, and sets a grid 82 within the area 81, thereby setting a plurality of areas 83 divided by the grid (see FIG. 8(a)). The sizes of the area 81 and the grid 82 (areas 83) are determined in advance.

[0079] In the map image memory 24 of the past image memory 31, a plurality of storage areas corresponding to a plurality of areas 83 set in the subject 25 are set.

[0080] The image processing device 20 generates a perspective image 84 with a field of view smaller than the range 81 set by the movable diaphragm 13. As shown in Fig. 8(b), when an area 83b where a center 85 of a field of view of a currently generated perspective image 84-2 is located is different from an area 83a where a center 85 of a field of view of a previously generated perspective image 84-1 in Fig. 8(a) is located, the currently generated perspective image 84-2 is stored for each of the areas 83a, 83b, 83c, and 83d in the storage areas in the map image memory 24 of the past image memory 31 corresponding to the areas 83a, 83b, 83c, and 83d overlapping with the field of view of the current perspective image 84-2, and the map image memory 24 is updated for each storage area. As a result, an image as shown in Fig. 9(a) is stored in the map image memory 24 of the past image memory 31.

[0081] In the virtual collimation mode, when the field of view of the movable aperture 13 is larger than that of the final perspective image (LIH image) 34 (FIG. 9(b)), the image completion device 21 completes the completion area 33 outside the final perspective image (LIH image) 34 with an image read out from one or more storage areas corresponding to the area 33 in the map image memory 24 of the past image memory 31 (FIG. 9(c)).

[0082] The X-ray fluoroscopic imaging apparatus of embodiment 2 can complement the complement area 33 outside the final fluoroscopic image (LIH image) 34 by storing the fluoroscopic images 84 in multiple storage areas (map image memory 24) corresponding to multiple areas overlapping the fluoroscopic images 84, even when the fluoroscopic images 84 are moved chronologically within a range 81 set for the subject 25 during fluoroscopic imaging.

[0083] A specific explanation will be given below using the flow in FIG.

[0084] In the flow of FIG. 7, steps that are the same as those in the flow of FIG. 2 of the first embodiment will be explained briefly.

[0085] In the following flow, steps 200 to 208 are in the fluoroscopy mode, steps 209 to 217 are in the virtual collimation mode, and steps 218 to 220 are in the imaging mode.

[0086] (Step 200) The image processing device 20 sets a range 81 for fluoroscopic imaging of the subject 25 and a plurality of regions 83 divided by a grid 82, as shown in FIG. 8(a).

[0087] (Steps 201-203) 2, fluoroscopy is started (step 201), a fluoroscopic image is generated from data from the X-ray detector 11, and stored in the display image memory 22 (step 202). The image processing device 20 causes the image display device 23 to display the fluoroscopic image 84 in the display image memory 22 (see FIG. 3(a)).

[0088] (Step 204) The image processing device 20 acquires from the system control device 16 the position of the aperture blades 13a of the movable aperture 13 and the position of the imaging system (the tabletop 12 and the X-ray tube 10).

[0089] (Step 205) Next, the image processing device 20 calculates the center of field of view 85 of the perspective image 84-2 in the display image memory 22, and determines whether the area 83b in which the center of field of view 85 is located is different from the area 83a in which the previously generated perspective image 84-1 is located. If they are different, the image processing device 20 proceeds to step 206 to update the storage area of ​​the map image memory 24 in the past image memory 31.

[0090] (Step 206) The image processing device 20 calculates the position of the field of view of the fluoroscopic image 84-2 from the position of the aperture blade 13a of the movable aperture 13 obtained in step 204 and the position of the imaging system (the tabletop 12 and the X-ray tube 10), and calculates areas 83a, 83b, 83c, and 83d on the subject 25 that overlap with the field of view of the fluoroscopic image 84-2 (see Figure 8(b)).

[0091] (Step 207) The image processing device 20 copies the currently generated fluoroscopic image 84-2 for each of the regions 83a, 83b, 83c, and 83d to the storage regions in the map image memory 24 of the past image memory 31 corresponding to the regions 83a, 83b, 83c, and 83d of the subject 25 that overlap the field of view of the fluoroscopic image 84-2. As a result, the map image memory 24 is updated for each storage region.

[0092] (Step 208) Similar to step 108 in the flow of FIG. 2, the image processing device 20 determines whether the operator has instructed it to end the fluoroscopy, and if not, returns to step 102 and repeats the operation of generating the next fluoroscopy image (FIGS. 8(c) to (i)).

[0093] On the other hand, if an instruction to end fluoroscopy has been issued, the image processing device 20 proceeds to step 209 .

[0094] (Step 209) In step 109, in order to execute the virtual collimation mode, if the operator has instructed using the operation device 15 to change the position (field of view) of the movable diaphragm 13, the system controller 16 controls the movable diaphragm 13 to execute the change. Also, if the operator has instructed using the operation device 15 to change the position of the imaging system (top plate 12 and X-ray tube 10), the system controller 16 changes the relative positions of the top plate 12 and the X-ray tube 10.

[0095] (Step 210) The image complement device 21 receives the position of the movable diaphragm 13 and the position of the imaging system (top plate 12 and X-ray tube 10) from the system control device 16, and calculates the position of the field of view (region of interest) of the movable diaphragm 13. (Steps 211, 212, 215) The image completion device 21 determines whether the field of view (area of ​​interest) of the movable aperture 13 calculated in step 210 is larger than the final perspective image (LIH image) 34 in the display image memory 22, and if the field of view (area of ​​interest) of the movable aperture 13 is less than or equal to the size of the final perspective image (LIH image) 34, no completion is necessary, so the image completion device 21 proceeds to step 215.

[0096] In step 215, the image complementing device 21 generates an image in which a mark (dotted line) indicating the current position of the field of view of the movable diaphragm 13 is superimposed on the final perspective image (LIH image) 34, and then proceeds to step 217.

[0097] On the other hand, if the field of view (region of interest) of the movable aperture 13 is larger than the size of the final perspective image (LIH image) 34, proceed to step 212 and obtain an image of the region corresponding to the field of view (region of interest) of the movable aperture 13 from the image in the map image memory 24 (Figure 9(a)).

[0098] (Step 213) 2, the image complement device 21 reduces and displays the perspective image in the display image memory 22 displayed on the image display device 23 (FIG. 9(b)). As a result, a complement area 33 is displayed around the final perspective image (LIH image) 34.

[0099] (Step 214) The image complement device 21 places the image acquired from the map image memory 24 in a complement area 33 outside the final perspective image (LIH image) 34 (FIG. 9(c)). In this way, a complemented image is generated.

[0100] (Step 216) The image complement device 21 displays the position of the adjustable aperture by surrounding the outside of the complemented image with a dotted line, and then proceeds to step 217.

[0101] (Step 217) The image completion device 21 displays the image generated in step 215 or step 216 on the image display device 23 .

[0102] (Steps 218~219) Next, similarly to steps 121 and 122 in FIG. 2, the system controller 16 determines whether or not an instruction to perform X-ray photography has been given by the operator, and if so, performs X-ray photography. (Step 220) Similar to step 123 in FIG. 2, the system controller 16 proceeds to step 201 to replay the fluoroscopic view, or ends, according to instructions from the operator.

[0103] By operating the X-ray fluoroscopy device according to the flow of Figure 7 described above, the periphery of the final fluoroscopy image (LIH image) 34 can be complemented even if the field of view of the fluoroscopy image 84 moves over time.

[0104] In the second embodiment, the configuration and operation other than those described above are similar to those in the first embodiment, so the description will be omitted.

[0105] <<Embodiment 3>> The X-ray fluoroscopic imaging apparatus of the third embodiment will be described with reference to Figs.

[0106] In the third embodiment, if the position of the subject has changed between the time when the fluoroscopic image was stored in the past image memory 31 and the time when the complementary image was generated, the change in position is detected and reflected in the complementary image. The change in the subject's position is calculated from the camera image. More specifically, the X-ray fluoroscopic imaging apparatus includes a subject position calculation device 29 and a subject position memory 27. The subject position calculation device 29 receives an image from a camera 61 arranged at a position where the subject 25 on the top board 12 can be imaged, and calculates the position of the subject 25 on the top board 12. The calculation result of the subject position calculation device 29 is stored in the subject position memory 27. The subject position calculation device 29 calculates the position of the subject 25 when storing the currently generated fluoroscopic image in the past image memory 31 from the image of the camera 61 and stores the calculated position in the subject position memory 31. In addition, in the virtual collimation mode, before generating an interpolated image, the subject position calculation device 29 calculates the position of the subject 25 from the image of the camera 61 and obtains the difference from the position of the subject 25 stored in the subject position memory 27. The image complementing device 21 adjusts the position where the outer region 33 of the final perspective image (LIH image) 34 is complemented by the perspective images stored in the past image memory 31 based on the calculated difference.

[0107] FIG. 10 is a block diagram showing the overall configuration of the X-ray fluoroscopic imaging apparatus of the third embodiment, and FIG. 11 is a flowchart showing the operation.

[0108] 10, a camera 61 is provided at a position where it can image a subject 25. The X-ray fluoroscopic imaging apparatus of the third embodiment is provided with a subject position memory 27, an imaging system / aperture position memory 28, and a subject position calculation device 29. The functions of each of these units will be made clear in the description of the flow in FIG.

[0109] The camera 61 may be attached to the X-ray fluoroscopic imaging device, or may be installed on a wall or ceiling of the examination room. It is also possible to use a camera, such as a surveillance camera, that is installed in the examination room in advance for another purpose as the camera 61, and to configure the system control device 16 to receive an image from the camera installed in the examination room and calculate the position of the subject 25.

[0110] Hereinafter, the operation of the X-ray fluoroscopic imaging apparatus of the third embodiment will be specifically described with reference to the flow of FIG.

[0111] In the flow of FIG. 11, steps similar to those in the flow of FIG. 2 of the first embodiment or the flow of FIG. 7 of the second embodiment will be explained briefly.

[0112] In the following flow, steps 301 to 307 are in the fluoroscopy mode, steps 308 to 317 are in the virtual collimation mode, and steps 318 to 320 are in the imaging mode.

[0113] (Steps 301 to 303) 2, fluoroscopy is started (step 301), a fluoroscopic image is generated from data from the X-ray detector 11, and stored in the display image memory 22 (LIH) (step 302). The image processing device 20 causes the image display device 23 to display the fluoroscopic image 84 in the display image memory 22 (see FIG. 3(a)).

[0114] (Step 304) The system control device 16 causes the subject position calculation device 29 to calculate the position of the subject 25 on the top plate 12 from the image of the camera 61, and outputs the calculated position of the subject 25 on the top plate 12 to the subject position memory 27, where it is stored.

[0115] (Step 305) Next, the system control device 16 obtains the positions of the aperture blades 13a of the movable aperture 13 and the position of the imaging system (the top board 12 and the X-ray tube 10), and stores them in the imaging system / aperture position memory .

[0116] (Step 306) The image processing device 20 copies the perspective image (last perspective image (LIH image)) in the display image memory 22 to the past image memory 31, similarly to step 106 in the flow of FIG.

[0117] (Step 307) The image processing device 20 determines whether or not the operator has instructed to end fluoroscopy, similarly to step 108 in the flow of Fig. 2, and if not, returns to step 302 to repeat the operation of generating the next fluoroscopy image. On the other hand, if the operator has instructed to end fluoroscopy, the image processing device 20 proceeds to step 308.

[0118] (Step 308) In step 308, if the operator has instructed using the operation device 15 to change the position (field of view) of the movable diaphragm 13, the system controller 16 controls the movable diaphragm 13 to execute the instruction. Also, if the operator has changed the position of the imaging system (top plate 12 and X-ray tube 10) using the operation device 15, the system controller 16 changes the relative positions of the top plate 12 and the X-ray tube 10.

[0119] (Step 309) The image complement device 21 receives the position of the movable diaphragm 13 and the position of the imaging system (top plate 12 and X-ray tube 10) from the system control device 16, and calculates the position of the field of view (region of interest) of the movable diaphragm 13.

[0120] (Steps 310 and 325) The image completion device 21 determines whether the field of view (area of ​​interest) of the movable aperture 13 calculated in step 210 is larger than the final perspective image (LIH image) 34 in the display image memory 22, and if the field of view (area of ​​interest) of the movable aperture 13 is less than or equal to the size of the final perspective image (LIH image) 34, no completion is necessary, so the image completion device 21 proceeds to step 325.

[0121] In step 325 , the image complementing device 21 generates an image in which a mark (dotted line) indicating the current position of the field of view of the movable diaphragm 13 is superimposed on the final perspective image (LIH image) 34 , and then proceeds to step 318 .

[0122] On the other hand, if the field of view (region of interest) of the movable diaphragm 13 is larger than the size of the final perspective image (LIH image) 34 , the process proceeds to step 311 .

[0123] (Step 311) In step 311, the system control device 16 causes the subject position calculation device 29 to calculate the current position of the subject 25 on the top board 12 from the image of the camera 61 at the current time. The system control device 16 compares the calculated current position of the subject with the position of the subject 25 at the time of step 304 stored in the subject position memory 27, and calculates the position difference. This makes it possible to determine the change in position of the subject 25 on the top board 12 between the time when the fluoroscopic image was stored in the past image memory 31 in step 306 and the current time (FIG. 12(a)).

[0124] (Step 312) In step 312, the system control device 16 acquires the current position of the aperture blades 13a of the movable aperture 13 and the position of the imaging system (the tabletop 12 and the X-ray tube 10). Then, the system control device 16 calculates the difference between the position of the aperture blades 13a of the movable aperture 13 stored in the imaging system / aperture position memory 28 in step 305 and the position of the imaging system (the tabletop 12 and the X-ray tube 10). This makes it possible to obtain the difference between the position of the aperture blades 13a of the movable aperture 13 and the position of the imaging system (the tabletop 12 and the X-ray tube 10) at the time when the fluoroscopic image was stored in the past image memory 31 in step 306 and the current time.

[0125] (Step 313) In step 313, the image completion device 21 calculates the position of the field of view (region of interest) of the movable aperture 13 on the fluoroscopic image (final fluoroscopic image (LIH image)) in the past image memory 31 from the difference in the position of the subject 25 calculated in step 311 and the difference in the imaging system and aperture position calculated in step 312.

[0126] (Step 314) 2, the image complement device 21 reduces and displays the final perspective image (LIH image) 34 of the display image memory 22 displayed on the image display device 23 (FIG. 12(b)). As a result, a complement area 33 is displayed around the final perspective image (LIH image) 34.

[0127] (Step 315) The image complement device 21 places the image acquired from the past image memory 31 in a complement area 33 outside the final perspective image (LIH image) 34 to generate a complement image (FIG. 12(b)). At this time, the complement area 33 is complemented based on the position of the field of view (region of interest) of the movable diaphragm 13 on the perspective image (final perspective image (LIH image)) in the past image memory 31, which was determined in step 313.

[0128] (Step 316) The image complement device 21 displays the position of the adjustable diaphragm 13 by surrounding the outside of the complemented image with a dotted line, and then proceeds to step 31.

[0129] (Step 317) The image completion device 21 displays the image generated in step 315 or step 316 on the image display device 23 .

[0130] (Steps 318~319) Similar to steps 121 and 122 in FIG. 2, the system controller 16 determines whether or not an instruction to take an X-ray photograph has been given by the operator, and if so, carries out the X-ray photograph. (Step 320) Similar to step 123 in FIG. 2, system controller 16 proceeds to step 201 to replay the fluoroscopic image, or returns to step 308, in accordance with an instruction from the operator.

[0131] In the third embodiment, if the position of the subject has changed between the time when the fluoroscopic image was stored in the past image memory 31 and the time when the complementary image was generated, the complementary image can be generated taking into account the change in the subject's position.

[0132] In the third embodiment, the configuration and operation other than those described above are similar to those in the first and second embodiments, so the description will be omitted.

[0133] <<Embodiment 4>> In the fourth embodiment, in the above-mentioned first to third embodiments, when there is no image data to be used to complement the complement region 33, or when the change in the posture of the subject is so great that complementation is not possible, a mark (e.g., hatching) indicating that there is no data in the complement region 33 is displayed as shown in FIG. 13.

[0134] For example, in embodiment 2, if the map image memory 24 is empty or no image data is stored in the storage area corresponding to the field of view of the movable aperture 13, there is no image that can be used to complement the complement area 33.

[0135] Therefore, as shown in the flow of Fig. 14, step 401 is inserted between step 213 and step 214 of the flow of Fig. 7 of the second embodiment, to make a flow for confirming that the map image memory 24 is not empty. If the map image memory 24 is empty in step 401, hatching is displayed (step 402) to indicate that there is no data in the complementation area 33 around the final perspective image (LIH image) 34, as shown in Fig. 13.

[0136] This allows the operator to easily understand that there is no complementary image by seeing the hatching displayed around the image in FIG.

[0137] 15, step 411 may be added between steps 314 and 315 of the flow of embodiment 3 in FIG. 11, in which it is determined whether or not the area corresponding to the complement area 33 in the past image memory 31 is empty. If the area corresponding to the complement area 33 in the past image memory 31 is empty in step 411, hatching is displayed indicating that there is no data in the complement area 33 around the final perspective image (LIH image) 34 (step 412), as shown in FIG.

[0138] This allows the operator to understand that, since there is no complementary image, the position of the subject 25 has changed between the time when the last fluoroscopic image (LIH image) was recorded and the current time.

[0139] Furthermore, as an application example of the third embodiment, a flow chart of FIG. 16 is shown.

[0140] 16, in step 304, not only the position of the subject on the tabletop but also its posture is detected from the image of camera 61 and stored in subject position memory 27. Also in step 311, not only the current position of the subject but also its posture is calculated, and a difference between the position and posture in subject position memory 27 is calculated. In step 313, the position of the region of interest on the image in the past image memory is calculated using the calculated difference between the position and posture of subject 25.

[0141] Step 421 is performed between steps 314 and 315. In step 421, if the change in the posture (orientation, etc.) of the subject is greater than a certain amount, the process proceeds to step 422, where hatching is displayed in the complementation area 33 around the final fluoroscopic image (LIH image) 34 to indicate that no image was available for complementation (step 422).

[0142] In this way, even if the change in the posture of the subject is greater than a predetermined amount, it is possible to show by hatching that there are no images available for complementation. Also, since there are no complementary images, the operator can understand that the position of the subject 25 has changed between the time when the last fluoroscopic image (LIH image) was recorded and the current time. [Explanation of symbols]

[0143] 10 X-ray tube 11 X-ray detector 12 Tabletop 13a Aperture blades 14 High voltage generator 15 Controller 16 System Control Unit 17 Mechanism control device 18 Past Image Memory 20 Image processing device 21 Image Completion Device 22 Display Image Memory 23 Image display devices 24 Map Image Memory 25 Subject 27 Subject position memory 28 Imaging system / Aperture position memory 29 Subject position calculation device 31 Past Image Memory 32 field of view 33 areas 34 Final fluoroscopic image (LIH image) 36 Dotted Line 41 Maximum field of view size 42 Second size 44 Field of view size 61 Camera 81 Range 82 Lattice 83 areas 83a area 83b area 83c~83g area 84 X-ray images 85 Center of visual field

Claims

1. the apparatus comprises a tabletop on which a subject is placed, an X-ray tube which irradiates X-rays onto the subject, a movable aperture which adjusts an irradiation range of the X-rays irradiated from the X-ray tube, an X-ray detector which detects X-rays which have passed through the subject, an image processing device capable of generating fluoroscopic images and still X-ray images from an output of the X-ray detector, a display image memory which stores each time the image processing device generates a fluoroscopic image at a predetermined rate as a current final fluoroscopic image and holds it until the next fluoroscopic image is generated and displays it on a connected image display device, a past image memory which stores fluoroscopic images generated by the image processing device prior to the current time, and an image complementing device; the image processing device includes a fluoroscopy mode for generating the fluoroscopy image, an imaging mode for generating the X-ray image, and a virtual collimation mode for causing the image display device to display a final fluoroscopy image stored in the display image memory superimposed on a mark indicating the position of the movable diaphragm after the end of the fluoroscopy mode and before the fluoroscopy mode is resumed, or after the end of the fluoroscopy mode and before the imaging mode is performed; The image complementation device is characterized in that, in the virtual collimation mode, when the field of view of the movable diaphragm is larger than the final fluoroscopic image stored in the display image memory and the fluoroscopic image stored in the past image memory includes an image of an area outside the final fluoroscopic image, the image complementation device generates an image in which the outer area of ​​the final fluoroscopic image is complemented by the fluoroscopic image stored in the past image memory.

2. 2. The X-ray fluoroscopic imaging apparatus according to claim 1, The image processing device is characterized in that, in the fluoroscopy mode, when the field of view of the currently generated fluoroscopic image is larger in size or displaced in position compared with the field of view of the fluoroscopic image already stored in the past image memory, the image processing device updates the currently generated fluoroscopic image by storing it in the past image memory.

3. 3. The X-ray fluoroscopic imaging apparatus according to claim 2, wherein the past image memory includes a first past image memory for storing an image having a maximum field of view size of the movable aperture, and a second past image memory for storing an image having a second predetermined size smaller than the maximum field of view size, the image processing device, in the fluoroscopy mode, stores the currently generated fluoroscopic image in the second past image memory when the field of view of the currently generated fluoroscopic image is larger than a second size and smaller than the maximum field of view size, and stores the currently generated fluoroscopic image in the first past image memory when the field of view of the currently generated fluoroscopic image is the maximum field of view size.

4. 4. The X-ray fluoroscopic imaging apparatus according to claim 3, an image complementing device for selecting one of the fluoroscopic images stored in the first past image memory and the second past image memory, whichever is more recently generated, when the field of view of the movable diaphragm is larger than the final fluoroscopic image and smaller than the second size, in the virtual collimation mode, and using the selected fluoroscopic image to complement an outer region of the final fluoroscopic image.

5. 4. The X-ray fluoroscopic imaging apparatus according to claim 3, The image complementation device is characterized in that, in the virtual collimation mode, when the field of view of the movable aperture is larger than the final fluoroscopic image and larger than the second size, the image complementation device complements an outer area of ​​the final fluoroscopic image with a fluoroscopic image stored in the first past image memory.

6. 2. The X-ray fluoroscopic imaging apparatus according to claim 1, further comprising a mechanism for relatively moving a field of view of the movable diaphragm on the subject by relatively changing a positional relationship between the top plate and the X-ray tube, the image processing device, in the fluoroscopy mode, sets a range for the object on the tabletop, sets a grid in the range, and sets a plurality of regions divided by the grid; A plurality of storage areas corresponding to the plurality of areas are set in the past image memory, said image processing device generates a fluoroscopic image of a field of view smaller than the range set by said movable diaphragm, and when a region among the plurality of regions in which a center of the field of view of the currently generated fluoroscopic image is located is different from a region in which a center of the field of view of the previously generated fluoroscopic image is located, said image processing device stores the currently generated fluoroscopic image for each region in said storage regions of said past image memory corresponding to one or more of said regions overlapping the field of view of the current fluoroscopic image.

7. 7. The X-ray fluoroscopic imaging apparatus according to claim 6, wherein the image complementing device complements an outer region of the final fluoroscopic image with an image read out from one or more of the storage areas corresponding to the outer region of the past image memory when a field of view of the movable diaphragm is larger than that of the final fluoroscopic image in the virtual collimation mode.

8. 2. The X-ray fluoroscopic imaging apparatus according to claim 1, wherein the image complementing device adjusts a position at which an outer region of the final fluoroscopic image is complemented by a fluoroscopic image stored in the past image memory based on a change in a position of the subject on the tabletop.

9. 9. The X-ray fluoroscopic imaging apparatus according to claim 8, further comprising: a subject position calculation device that receives an image of the subject on the tabletop from a camera disposed at a position capable of photographing the subject, and calculates a position of the subject on the tabletop; and a subject position memory that stores a calculation result of the subject position calculation device, the subject position calculation device calculates a position of the subject from the image of the camera when storing the currently generated fluoroscopic image in the past image memory, and stores the calculated position in the subject position memory, and in the virtual collimation mode, calculates a position of the subject from the image of the camera before generating the complemented image, and obtains a difference between the position of the subject and the position stored in the subject position memory, thereby obtaining the change; The X-ray fluoroscopic imaging apparatus according to claim 1, wherein the image complementing device adjusts a position where an outer region of the final fluoroscopic image is complemented by the fluoroscopic image stored in the past image memory based on the difference.

10. 2. The X-ray fluoroscopic imaging apparatus according to claim 1, wherein, in the virtual collimation mode, when the fluoroscopic image is not stored in the past image memory or when the fluoroscopic image stored in the past image memory does not include an image of an area outside the final fluoroscopic image, the image complement device displays a mark indicating that there is no complement image in the outer area of ​​the final fluoroscopic image.

11. An image processing device for generating a fluoroscopic image of an X-ray fluoroscopic imaging device, the image processing device includes a past image memory for storing a fluoroscopic image in a fluoroscopic mode; The image processing device executes a virtual collimation mode, after the end of the fluoroscopy mode and before resuming the fluoroscopy mode, or after the end of the fluoroscopy mode and before performing the imaging mode, in which a final fluoroscopy image last generated in the fluoroscopy mode and a mark indicating the position of a movable aperture of an X-ray fluoroscopy imaging device are superimposed and displayed on an image display device, and in the virtual collimation mode, when the field of view of the movable aperture of the X-ray fluoroscopy imaging device is larger than that of the final fluoroscopy image and the fluoroscopy image stored in the past image memory includes an image of an area outside the final fluoroscopy image, generates an image in which the outer area of ​​the final fluoroscopy image is complemented by the fluoroscopy image stored in the past image memory.

Images