X-ray diagnostic apparatus, medical information processing apparatus, and medical information processing program

Abstract

To perform radioscopy with high visibility by a stabilized medical device under a situation accompanied by pulsation and a respiratory motion, and under the radioscopy by changing an image magnification ratio.SOLUTION: An X-ray diagnostic apparatus includes an X-ray tube, an X-ray detection device, an image generation part, a feature point detection part, and a region setting part. The image generation part generates an X-ray image of a subject from X-ray data in association with a cardiac time phase. The feature point detection part detects the position of a feature point that a medical device has in a first search region, which is a predetermined search region in a first X-ray image corresponding to a current cardiac cycle of the X-ray image, for each first cardiac time phase in the current cardiac cycle. The region setting part sets a second search region different from the first search region on the basis of the position of a feature point detected in a second cardiac time phase the closest to the first cardiac time phase of a second X-ray image corresponding to a past cardiac cycle rather than the current cardiac cycle. The feature point detection part detects the position of a feature point in the second search region when the second search region is set by the region setting part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and the drawings relate to an X-ray diagnostic apparatus, a medical information processing apparatus, and a medical information processing program. [Background technology]

[0002] A treatment called IVR (Interventional Radiology) using medical imaging diagnostic equipment such as X-ray angiography equipment is widely used. IVR, which literally translates to "image-guided treatment" in Japanese, uses medical imaging diagnostic equipment such as X-ray angiography equipment (hereinafter simply referred to as an angiography equipment), X-ray CT equipment, or ultrasound diagnostic equipment to see inside the body and insert thin medical devices into blood vessels to diagnose and treat targeted diseases. Medical devices inserted into blood vessels include, for example, thin tubes called catheters, balloons and stents attached to the tip of catheters, and guidewires used to guide catheters to the areas within blood vessels to be diagnosed or treated.

[0003] In IVR using an angiography device, the doctor, who is the technician, manually operates medical devices such as guidewires and catheters to advance through the patient's blood vessels and reach the area to be diagnosed or treated, while observing the X-ray fluoroscopic images of the patient that are generated in real time by the angiography device.

[0004] For physicians performing procedures, it is extremely important that medical devices such as balloons, stents, and guidewires are clearly depicted in X-ray fluoroscopic images. Therefore, technologies have been developed to improve the visibility of medical devices such as stents in X-ray fluoroscopic images. For example, a technology is known that detects the position of a marker on a stent and displays the stent, which moves during the procedure, at approximately the same position on a display in successive frame images of X-ray fluoroscopic images.

[0005] However, with conventional technology, operation can become unstable in situations where the position of a medical device such as a stent changes due to pulsation or respiratory movement, or when X-ray fluoroscopy is performed with the image magnification ratio changed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-131371 Summary of the Invention [Problem to be solved by the invention]

[0007] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to fluoroscopically view a medical device such as a stent with stable and high visibility even under conditions involving pulsation or respiratory movement, or under conditions in which the magnification of the image is changed during fluoroscopy. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problem. Problems corresponding to the effects of the configurations shown in the embodiments described below can also be considered as other problems. [Means for solving the problem]

[0008] An X-ray diagnostic apparatus according to one embodiment includes an X-ray tube, an X-ray detection device, an image generation unit, a feature point detection unit, and a region setting unit. The X-ray tube irradiates X-rays onto a subject having a medical device inserted inside the body. The X-ray detection device collects X-rays that have passed through the subject as X-ray data. The image generation unit generates an X-ray image of the subject from the X-ray data in association with the cardiac phase. The feature point detection unit detects the positions of feature points of the medical device for each first cardiac phase in the current cardiac cycle in a first search region, which is a predetermined search region in a first X-ray image corresponding to the current cardiac cycle among the X-ray images. The region setting unit sets a second search region different from the first search region based on the position of the feature point detected in a second cardiac phase closest to the first cardiac phase in a second X-ray image corresponding to a cardiac cycle earlier than the current cardiac cycle in at least one of the following cases: (a) when no feature point is detected, (b) when the frame rate of the X-ray image changes from a first frame rate to a second frame rate lower than the first frame rate, and (c) when an X-ray image is generated by expanding a narrower narrow-area imaging range within the predetermined imaging range from a predetermined imaging range.When the second search region is set by the region setting unit, the feature point detection unit detects the position of the feature point in the second search region. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an example of the overall configuration of an X-ray diagnostic apparatus including a medical information processing apparatus according to an embodiment. [Figure 2] 1 is a diagram illustrating a medical device. [Figure 3] FIG. 10 is a diagram illustrating a process for fixing the display position of a medical device. [Figure 4] FIG. 4 is a diagram illustrating feature points and candidate points. [Figure 5] 4 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus according to the first embodiment. [Figure 6] 3A and 3B are diagrams for explaining a first X-ray image and a second X-ray image generated in association with cardiac phases. [Figure 7] FIG. 4 is a diagram illustrating a first setting example of a second search area in the first embodiment. [Figure 8] FIG. 6 is a diagram illustrating a second setting example of a second search area in the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating a third setting example of the second search area in the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating a fourth setting example of the second search area in the first embodiment. [Figure 11] FIG. 10 is a schematic diagram showing an example of the detailed configuration of an X-ray diagnostic apparatus according to a second embodiment. [Figure 12] 10 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus according to the second embodiment. [Figure 13] 1A to 1C are diagrams for explaining a plurality of consecutive frame images of X-ray fluoroscopic images at different frame rates. [Figure 14] FIG. 10 is a diagram illustrating an example of setting a second search area in the second embodiment. [Figure 15] 10 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus according to the third embodiment. [Figure 16] 3A to 3C are diagrams for explaining a plurality of consecutive frame images of X-ray fluoroscopic images of different imaging ranges. [Figure 17] FIG. 11 is a diagram illustrating an example of setting a second search area in the third embodiment. [Figure 18] FIG. 11 is a diagram illustrating a shooting area for a second search area in a modified example of the third embodiment. [Figure 19] FIG. 10 is a schematic diagram showing an example of the detailed configuration of an X-ray diagnostic apparatus according to a fourth embodiment. [Figure 20] 10 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus according to the fourth embodiment. [Figure 21] FIG. 13 is a diagram illustrating an example of setting a second search area in the fourth embodiment. [Figure 22] 10 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus according to the fifth embodiment. [Figure 23] FIG. 13 is a diagram illustrating an example of setting a second search area in the fifth embodiment. [Figure 24] FIG. 20 is a diagram illustrating a first setting example of a second search area in the sixth embodiment. [Figure 25] FIG. 20 is a diagram illustrating a second setting example of a second search area in the sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The X-ray diagnostic apparatus, medical information processing apparatus, and medical information processing program according to the embodiments will be described below with reference to the accompanying drawings. In each drawing, the same elements are designated by the same reference numerals, and redundant description will be omitted.

[0011] (Overall composition) 1 is a schematic diagram showing the configuration of an X-ray diagnostic apparatus 1 including a medical information processing apparatus 100 according to one embodiment. The X-ray diagnostic apparatus 1 includes a general radiography apparatus, an X-ray mobile apparatus, an X-ray angiography apparatus, an X-ray TV apparatus, etc. The X-ray diagnostic apparatus 1 may also be, for example, an X-ray fluoroscopic diagnostic apparatus used in gastrointestinal imaging examinations, etc., or a circulatory X-ray fluoroscopic diagnostic apparatus used in angiography examinations, etc.

[0012] The X-ray diagnostic apparatus 1 is composed of a gantry 2, a bed 3, a controller 4, and a console 5. The gantry 2, the bed 3, and the controller 4 are installed, for example, in a procedure room where examinations and treatments are performed. The console 5 and the medical information processing device 100 are installed, for example, in a control room adjacent to the procedure room.

[0013] The gantry device 2 includes an X-ray irradiation device 21, an X-ray detection device 22, a C-arm driving mechanism 23, and a C-arm 24.

[0014] The X-ray irradiator 21 is provided at one end of the C-arm 24. The X-ray irradiator 21 is provided so as to be movable back and forth under the control of the controller 4. The X-ray irradiator 21 has an X-ray source (for example, an X-ray tube 211) and a movable aperture device 212. The X-ray tube 211 receives high-voltage power from a high-voltage generator and generates X-rays according to the conditions of the high-voltage power.

[0015] The adjustable diaphragm device 212 movably supports diaphragm blades made of a material that blocks X-rays at the X-ray irradiation port of the X-ray tube 211. The adjustable diaphragm device 212 may be able to change the shape and position of the opening through which X-rays pass, thereby changing the outer shape, size, and position of the X-ray irradiation range, simply by moving the diaphragm blades, without moving the X-ray irradiation device 21. Note that a radiation quality adjustment filter that adjusts the radiation quality of the X-rays generated by the X-ray tube 211 may be provided in front of the X-ray tube 211.

[0016] The X-ray detection device 22 is provided at the other end of the C-arm 24, facing the X-ray irradiation device 21. The X-ray detection device 22 is provided so as to be movable back and forth under the control of the controller 4. The X-ray detection device 22 includes an FPD (Flat Panel Detector) 221 and an ADC (Analog to Digital Converter) 222.

[0017] The FPD 221 has a plurality of detecting elements arranged two-dimensionally. The detecting elements of the FPD 221 are arranged so that the scanning lines and signal lines intersect at right angles. A grid may be provided on the front surface of the FPD 221. The grid is made of grid plates made of lead or other material with high X-ray absorption and aluminum or wood or other material with high X-ray transmittance, arranged alternately, to absorb scattered rays incident on the FPD 221 and improve the contrast of the X-ray image.

[0018] The ADC 222 converts the projection data of the time-series analog signal (video signal) output from the FPD 221 into a digital signal, and outputs it to the console 5.

[0019] The X-ray detection device 22 may be an II (Image Intensifier)-TV system. In an II-TV system, X-rays that have passed through the subject and X-rays that are directly incident on the subject are converted into visible light, and the brightness is doubled in the photo-electro-photo conversion process to form sensitive projection data. The optical projection data is then converted into an electrical signal using a CCD (Charge Coupled Device) image sensor. The X-ray detection device 22 may also be a CMOS-FPD having multiple X-ray detection elements made of semiconductor elements that accumulate signal charges according to the amount of incident X-rays.

[0020] The C-arm 24 positions the X-ray irradiator 21 and the X-ray detector 22 facing each other with the subject at the center. Under the control of the controller 4, the C-arm 24 moves the X-ray irradiator 21 and the X-ray detector 22 as a unit in an arc direction of the C-arm 24 by the C-arm drive mechanism 23. Note that, although the following description takes as an example a configuration in which the X-ray diagnostic apparatus 1 is provided with the C-arm 24 and the C-arm 24 operates the X-ray irradiator 21 and the X-ray detector 22 as a unit, the present invention is not limited to this case. For example, the X-ray diagnostic apparatus 1 may not be provided with the C-arm 24, and the X-ray irradiator 21 and the X-ray detector 22 may each be operated independently.

[0021] FIG. 1 shows an example of the configuration of a single-plane type X-ray diagnostic device 1 having only one C-arm, but the X-ray diagnostic device 1 may also be a bi-plane type X-ray diagnostic device 1 that uses two arms to enable fluoroscopy from two directions simultaneously.

[0022] The bed 3 is supported on the floor surface and supports a top plate (catheter table) 31. The bed 3 can slide (in the X- and Z-axis directions), move up and down (in the Y-axis direction), and roll the top plate 31 under the control of the controller 4. Note that the gantry device 2 will be described as an under-tube type in which the X-ray irradiator 21 is located below the top plate 31, but the gantry device 2 may also be an over-tube type in which the X-ray irradiator 21 is located above the top plate 31.

[0023] The controller 4 includes a processor and a memory circuit (not shown). For alignment, the controller 4 controls the driving of the X-ray irradiator 21, the X-ray detector 22, and the C-arm 24 of the gantry device 2, and the driving of the bed 3, in accordance with the processing circuit 51. The controller 4 also controls the operations of the X-ray irradiator 21, the adjustable aperture device 212, the X-ray detector 22, the C-arm driving mechanism 23, etc., for surgical X-ray photography and X-ray fluoroscopy, in accordance with the processing circuit 51.

[0024] The console 5 is an example of an image processing device, and includes a processing circuit 51, a memory circuit 52, an input interface 53, a network interface 54, and a display 55. The console 5 does not have to be provided independently, and the functions of the memory circuit 52 and the processing circuit 51 may be performed by the memory circuit and the processor of the controller 4, respectively.

[0025] The display 55 is configured by a general display device such as a liquid crystal display or an OLED (Organic Light Emitting Diode) display. The display 55 is a display device and may also include, for example, a GUI (Graphical User Interface) or a touch panel that can accept operations. The display 55 may be, for example, a large display that is placed in a position that is easily visible to the operator during surgery. The display 55 displays X-ray fluoroscopic images and various information to support the procedure. The display 55 is an example of a display unit.

[0026] The network interface 54 is a circuit for connecting to various networks such as a hospital network or the Internet via wired or wireless means.

[0027] The input interface 53 includes an operable input device and an input circuit that inputs a signal from the input device. The input device can be realized by a mouse, keyboard, trackball, switch, button, joystick, touchpad that performs input operation by touching the operation surface, touchscreen that combines a display and touchpad, a non-contact input circuit using an optical sensor, a voice input circuit, etc. When the input device accepts an input operation, the input circuit generates an electrical signal corresponding to the input operation and outputs it to the processing circuit 51.

[0028] The input interface 53 includes a circuit for connecting a portable memory such as a USB memory, a memory card, a magnetic disk, or an optical disk, and inputting data recorded in the portable memory.

[0029] The storage circuitry 52 of the console 5 is configured by, for example, semiconductor memory elements such as RAM (Random Access Memory) and flash memory, a hard disk, an optical disk, etc. The storage circuitry 52 stores various processing programs (including application programs and OS (Operating System) etc.) used in the processing circuitry 51 and data required for executing the programs. The storage circuitry 52 can also store various data such as image data input via the input interface 53 and the network interface 54.

[0030] The processing circuitry 51 of the console 5 has a dedicated or general-purpose processor, and is a circuit that controls the operation of the entire X-ray diagnostic apparatus 1 through software processing by executing programs stored in the memory circuitry 52. ​​The processing circuitry 51 controls the controller 4 based on input via the input interface 53, and the execution of various programs and various data read from the memory circuitry 52. ​​The processing circuitry 51 also realizes various functions including an image generation function F1. The image generation function F1 of the processing circuitry 51 generates a frame image (i.e., an X-ray image) by X-ray fluoroscopy from an X-ray detection signal of the subject acquired in real time during a procedure using the medical device 60.

[0031] The medical information processing device 100 is a device provided in the X-ray diagnostic apparatus 1, and includes a processing circuit 101 and a memory circuit 102. The medical information processing device 100 does not have to be provided independently, and the functions of the memory circuit 102 and the processing circuit 101 may be performed by a memory circuit and a processor of the controller 4, respectively.

[0032] The storage circuitry 102 of the medical information processing device 100 is configured by, for example, semiconductor memory elements such as RAM (Random Access Memory) and flash memory, a hard disk, an optical disk, etc. The storage circuitry 102 stores various processing programs (including application programs and OS (Operating System) etc.) used in the processing circuitry 101 and data required for executing the programs. The storage circuitry 102 can also store various data such as image data input via an input interface or network interface (not shown).

[0033] The processing circuitry 101 of the medical information processing device 100 has a dedicated or general-purpose processor, and realizes various functions including a feature point detection function F2, an area setting function F3, a display control function F4, an information acquisition function F5, and a blood vessel detection function F6 based on the execution of various programs and various data read from the memory circuitry 102.

[0034] (Medical Devices) 1 illustrates a medical device 60 used in the procedure and a device operating unit 61. The device operating unit 61 is an instrument that allows a surgeon such as a doctor to manually control the operation of the medical device 60 so that it can be inserted into a blood vessel and advanced to a predetermined target site.

[0035] The medical device 60 is a medical instrument that is inserted into tubular tissue such as a blood vessel to diagnose or treat a subject. Examples of medical devices 60 that can be inserted into blood vessels include thin tubes called catheters, balloons or stents attached to the tip of catheters, and guidewires for guiding catheters to diagnostic or therapeutic sites within blood vessels. The medical device 60 may also be a device for transplanting stem cells in the field of regenerative medicine, or a therapeutic device such as an artificial valve or vascular graft.

[0036] FIG. 2 illustrates, as an example, a medical device 60 in which a stent is attached to the distal end of a catheter and two markers, 1 and 2, are provided on both ends of the stent. Markers 1 and 2 are made of, for example, a metal that is opaque to radiography. Markers 1 and 2 are examples of characteristic points P1 and P2 that the medical device 60 has in an X-ray fluoroscopic image. Note that, although FIG. 2 shows two characteristic points, markers 1 and 2, the number of characteristic points that the medical device 60 has is not limited to two, and may be one, or three or more.

[0037] For the operator, it is extremely important for the diagnosis and treatment of the subject that a medical device 60 such as a stent is clearly depicted in an X-ray fluoroscopic image. Therefore, a technique is known in which two markers depicted in each sequentially acquired X-ray image are detected, and the X-ray images are subjected to deformation and alignment processing so that the positions of the two markers in each X-ray image are the same as in the previous image, thereby displaying a moving image in which the device appears virtually stationary. This technique can improve the visibility of the medical device 60 in the X-ray fluoroscopic image in real time. This technique is used when checking the placement position of a medical device 60 such as a stent in detail, or when positioning the medical device 60 when overlapping.

[0038] During the procedure, the medical device 60 moves due to the pulsation of the heart and blood vessels and the respiratory movement caused by the expansion and contraction of the lungs, and also moves on the display. The positions of characteristic points of the medical device 60 are detected, and the medical device 60, such as a stent, that moves during the procedure is displayed at approximately the same position on the display (for example, in the center of the display) in multiple consecutive frame images of the X-ray fluoroscopic images.

[0039] 3 is a diagram illustrating the flow until the display position of a medical device 60 such as a stent is fixed. As shown in FIG. 3, after X-ray fluoroscopy is started (step ST100), in a learning mode, the positions of characteristic points of the medical device are detected and the characteristic points are identified (step ST110).

[0040] Because pulsation and respiratory movements are regular (periodic), the medical device 60, which moves in accordance with these movements, exhibits regular (periodic) positional movement. In the learning mode, the positions of multiple candidate points are comprehensively detected using X-ray images from a predetermined period, and candidate points that move regularly (periodic) are identified as feature points. For example, the movement of multiple candidate points between multiple consecutive frame images is detected, and candidate points that move within a predetermined search area between consecutive frame images of X-ray fluoroscopic images are identified from the multiple candidate points. Note that when multiple feature points are used, the relative positional relationship between the multiple feature points in each frame image may be used as an index for identifying the feature points from the multiple candidate points. In the learning mode, for example, approximately 40 frame images are used.

[0041] FIG. 4 is a diagram illustrating feature points and candidate points. A candidate point is a point that may be a feature point of a medical device 60. In FIG. 4, among multiple candidate points P1, P2, P3, and P4, candidate points P1 and P2 are detected within a predetermined search region in all frame images Im(t11), Im(t12), Im(t13), Im(t14), and Im(t15) at elapsed times T=t11, t12, t13, t14, and t15. Note that in elapsed time T=tqr, q indicates consecutive cardiac cycles and r indicates a cardiac phase within one cardiac cycle. Here, the predetermined search region is a predetermined region centered on the position of a candidate point depicted in a frame image at elapsed time T immediately preceding the frame image for which the feature point position is to be detected, and further including the surrounding area.

[0042] More specifically, candidate points P1 and P2 are detected in frame image Im(t11), search areas A1(t12) and A2(t12) on frame image Im(t12), search areas A1(t13) and A2(t13) on frame image Im(t13), search areas A1(t14) and A2(t14) on frame image Im(t14), and search areas A1(t15) and A2(t15) on frame image Im(t15). Therefore, candidate points P1 and P2 are identified as feature points.

[0043] After the feature points of the medical device are identified in the learning mode, the movement of the feature points detected in the learning mode is tracked in the tracking mode (step ST120). In this case, for example, image processing such as averaging is used to emphasize the edge of the medical device 60 such as a stent, thereby improving visibility.

[0044] In the tracking mode, even if the positions of the medical device 60 or the target blood vessel fluctuate due to pulsation, the display position of the medical device 60 on the display 55 is fixed (step ST130). The placement state of the medical device 60 can be confirmed by displaying an image of the fixed medical device 60.

[0045] However, in conventional tracking modes, if a feature point moves beyond a predetermined search area between consecutive frame images of X-ray fluoroscopic images, the feature point may no longer be identified as a feature point or its position may no longer be detected. Thus, for example, under circumstances in which the position of the medical device 60 changes between consecutive frame images due to pulsation or respiratory movement, or under circumstances in which X-ray fluoroscopy is performed with a different image magnification, operation may become unstable. Therefore, to prevent the feature points P1 and P2 from moving beyond the predetermined search area between consecutive frame images, for example, the frame rate or imaging range has been limited. The X-ray diagnostic apparatus 1 according to the embodiment enables the detection of the positions of the feature points P1 and P2 even if they move beyond the predetermined search area between consecutive frame images.

[0046] Although the following describes an embodiment in a situation where the position of the medical device 60 changes between previous and next frame images due to pulsation, the present invention can also be implemented in a similar manner in a situation where the position of the medical device 60 changes between previous and next frame images due to respiratory movement. In the following description, in the case of respiratory movement, the cardiac phase can be read as the respiratory phase, and the cardiac cycle as the respiratory cycle.

[0047] (First embodiment) 1, the processing circuitry 51 of the X-ray diagnostic apparatus 1 and the processing circuitry 101 of the medical information processing apparatus 100 realize an image generation function F1, a feature point detection function F2, an area setting function F3, and a display control function F4. Each of these functions will be described with reference to the flowchart of FIG. 5 showing an example of the operation of the X-ray diagnostic apparatus 1, and with reference to FIGS. 6 to 10.

[0048] In step ST10, a first frame rate is set, which is a frame rate high enough to prevent feature points from moving beyond a predetermined search area between successive frame images of a plurality of consecutive frame images of an X-ray fluoroscopic image.

[0049] In step ST11, a predetermined imaging range is set. The predetermined imaging range is a wide imaging range that does not cause feature points to move beyond a predetermined search area between successive frame images of a plurality of X-ray fluoroscopic images.

[0050] In step ST12, the image generation function F1 generates an X-ray image (i.e., a frame image) of the subject from the X-ray data in association with the cardiac phase. The X-ray data is data obtained by irradiating X-rays from the X-ray tube 211 to a subject with a medical device inserted inside the body, and collecting the X-rays that have passed through the subject with the X-ray detection device 22.

[0051] 6 is a perspective view illustrating a first X-ray image and a second X-ray image generated in synchronization with the waveform of an electrocardiograph (ECG) 70 and associated with cardiac phases. In FIG. 6, frame images Im(t01), Im(t02), Im(t03), Im(t04), and Im(t05) are generated in a past cardiac cycle associated with phases where the R-R wave interval is 0%, 20%, 40%, 60%, and 80%. Also, frame images Im(t11), Im(t12), Im(t13), Im(t14), and Im(t15) are generated in a current cardiac cycle associated with phases where the R-R wave interval is 0%, 20%, 40%, 60%, and 80%. In FIG. 6, five frame images are generated by dividing one cardiac cycle into five cardiac phases at predetermined intervals, but the number of frame images within one cardiac cycle is not limited to five and may be any number.

[0052] In step ST13, the feature point detection function F2 detects the position of a feature point of the medical device 60 for each first cardiac phase in the current cardiac cycle in a first search area in a first X-ray image corresponding to the current cardiac cycle among the X-ray images. The first search area is a predetermined search area in the first X-ray image. The predetermined search area is a predetermined area centered on the position of the feature point depicted in the frame image at the elapsed time T immediately before the frame image in which the position of the feature point is to be detected (for example, frame image Im(t11) in the case of frame image Im(t12) in FIG. 6), and further including the surrounding area.

[0053] In step ST14, it is determined whether or not the position of a feature point has been detected in the first search area in the first X-ray image. If a feature point has been detected (i.e., if YES in step ST14), the process proceeds to step ST17. If a feature point has not been detected (i.e., if NO in step ST14), the process proceeds to step ST15.

[0054] For example, in FIG. 6, the positions of feature points P1 and P2 of the medical device 60 have been detected in first search areas A1(t13) and A2(t13) within frame image Im(t13) in the current cardiac cycle. In contrast, attempts are being made to detect the positions of feature points P1 and P2 of the medical device 60 in first search areas A1(t12) and A2(t12) within frame image Im(t12). However, feature points P1 and P2 of the medical device 60 are outside the first search areas A1(t12) and A2(t12), and the positions of feature points P1 and P2 have not been detected in frame image Im(t12). Step ST15 is performed when the positions of feature points P1 and P2 are not detected.

[0055] In step ST15, the region setting function F3 sets a second search region different from the first search region based on the positions of feature points detected in a second cardiac phase closest to the first cardiac phase in a second X-ray image corresponding to a cardiac cycle earlier than the current cardiac cycle. The second X-ray image corresponding to a past cardiac cycle is acquired using the X-ray diagnostic apparatus 1 before or during diagnosis or treatment using the medical device 60.

[0056] In Fig. 6, the second X-ray image corresponding to the past cardiac cycle closest to the cardiac phase of the frame image Im(t12) in which the positions of the feature points P1 and P2 were not detected is the frame image Im(t02). Fig. 7 is a plan view of the frame image Im(t02) in the past cardiac cycle and the frame image Im(t12) in the current cardiac cycle in Fig. 6. As shown in Fig. 7, in step ST15, a second search area different from the first search areas A1(t12) and A2(t12) is set to detect the positions of the feature points P1 and P2 in the frame image Im(t12) that were not detected in the first search areas A1(t12) and A2(t12).

[0057] 7 to 10 are diagrams illustrating an example of setting the second search region in the first embodiment. As shown in Fig. 7, the region setting function F3 may set regions A1(t02) and A2(t02) centered on the positions of feature points P1 and P2 detected in the second cardiac phase as the second search region.

[0058] Furthermore, as shown in FIG. 8, the region setting function F3 may set regions D1(t02) and D2(t02) as second search regions, centered on the positions of feature points P1 and P2 detected in the second cardiac phase, so that the areas are larger than the first search regions A1(t12) and A2(t12).

[0059] Furthermore, as shown in FIG. 9, the region setting function F3 may set the second search region as the union region of the first search regions A1(t12) and A2(t12) and the regions A1(t02) and A2(t02) centered on the positions of the feature points P1 and P2 detected in the second cardiac phase.

[0060] Furthermore, as shown in FIG. 10, the region setting function F3 may set, as the second search region, the region that is the union of regions D1(t02) and D2(t02) that are larger in area than the first search regions A1(t12) and A2(t12), and regions A1(t02) and A2(t02) that are centered on the positions of feature points P1 and P2 detected in the second cardiac phase.

[0061] In step ST16, when the second search area is set by the area setting function F3, the feature point detection function F2 detects the positions of the feature points P1 and P2 in the second search area.

[0062] If the position of the feature point is not detected in the second search area, the second search area is repeatedly set until the position of the feature point is detected in the second search area. In this case, for example, the second search area may be set by sequentially going back from the present to the past, starting with the X-ray image corresponding to the past cardiac cycle closest to the current cardiac cycle, among the second X-ray images corresponding to cardiac cycles earlier than the current cardiac cycle, until the position of the feature point is detected in the second search area.

[0063] In step ST17, the display control function F4 controls the display of X-ray images aligned based on the feature points detected from each frame. Specifically, the display control function F4 controls the alignment of X-ray images including the first X-ray image based on the feature points detected in the second search area and the display of the aligned X-ray images. For example, the display control function F4 generates a corrected image by performing deformation, rotation, and movement processing on the X-ray image so that the feature points detected from each frame are aligned at approximately the same positions. The display control function F4 also controls the display of the corrected image. The display control function F4 also controls the display of a medical device 60, such as a stent, that moves during the procedure so that it is displayed at approximately the same position on the display (for example, in the center of the display) (step ST130 in FIG. 3). The display unit is, for example, the display 55.

[0064] In step ST18, it is determined whether to end the process depending on whether it is OK to complete the display of the aligned X-ray image. If the process is not finished (i.e., if NO in step ST18), the process proceeds to step ST12, where a new first X-ray image is generated. If the process is finished (i.e., if YES in step ST18), the process ends.

[0065] The X-ray diagnostic apparatus 1 according to the first embodiment is capable of detecting the positions of feature points even under conditions involving pulsation or respiratory movement, thereby enabling stable X-ray fluoroscopy of the medical device 60 with high visibility. Furthermore, the X-ray diagnostic apparatus 1 according to the first embodiment aligns the X-ray image based on the positions of feature points detected by the feature point detection function F2, and displays the aligned X-ray image. This allows for more stable observation of the medical device 60.

[0066] (Second embodiment) FIG. 11 is a schematic diagram showing an example of the detailed configuration of an X-ray diagnostic apparatus 1 according to a second embodiment. The second embodiment differs from the first embodiment in that the processing circuitry 101 further implements an information acquisition function F5. FIG. 12 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus 1 according to the second embodiment. The second embodiment differs from the first embodiment in that a second search area different from the first search area is set when the frame rate of the X-ray image changes from a first frame rate to a second frame rate lower than the first frame rate. In the second embodiment, after step ST13, the process proceeds to step ST20.

[0067] In step ST20, it is determined whether the frame rate of the X-ray image has been changed from the first frame rate to a second frame rate lower than the first frame rate. The information acquisition function F5 acquires information about the imaging conditions for acquiring X-ray data for generating the X-ray image.

[0068] If the frame rate of the X-ray image is changed from the first frame rate to a second frame rate lower than the first frame rate (i.e., if YES in step ST20), the process proceeds to step ST15. That is, if the information acquisition function F5 acquires information that the X-ray data is acquired at a low frame rate, the region setting function F3 sets a second search region in the first X-ray image that is different from the first search region. If NO in step ST20, the process proceeds to step ST17.

[0069] 13 is a diagram illustrating a plurality of consecutive frame images of X-ray fluoroscopic images at different frame rates. As shown in FIG. 13, when the frame rate is changed from a first frame rate FR1, which is high, to a second frame rate FR2, which is lower than the first frame rate, the time interval between the previous and next frame images becomes wider. When the time interval between the previous and next frame images becomes wider, for example, the movement distance of the medical device 60 between the previous and next frame images may become physically larger due to pulsation or respiratory movement. As a result, the position of a feature point may not be detected in a predetermined search area.

[0070] 13, for example, in the case of the first frame rate FR1, the feature points P1 and P2 are rendered within the search areas A1(t03) and A2(t03) on the frame image Im(t03). On the other hand, in the case of the second frame rate FR2, the feature points P1 and P2 are not rendered within the search areas A1(t13) and A2(t13) on the frame image Im(t13).

[0071] Fig. 14 is a diagram illustrating an example of setting a second search region in the second embodiment. Fig. 14 shows plan views of a frame image Im(t03) in a past cardiac cycle and a frame image Im(t13) in a current cardiac cycle in Fig. 13. As shown in Fig. 14, the region setting function F3 may set regions A1(t02) and A2(t02) as the second search region, with the positions of feature points P1 and P2 detected in the second cardiac phase as their centers. The region setting function F3 may set regions D1(t02) and D2(t02) as the second search region, with the positions of feature points P1 and P2 detected in the second cardiac phase as their centers, so that the areas of the first search regions A1(t12) and A2(t12) are larger than those of the first search regions A1(t12) and A2(t12).

[0072] Furthermore, the region setting function F3 may set, as the second search region, a region that is the union of the first search regions A1(t12) and A2(t12) and regions A1(t02) and A2(t02) that are centered on the positions of feature points P1 and P2 detected in the second cardiac phase. The region setting function F3 may set, as the second search region, a region that is the union of regions D1(t02) and D2(t02) that are larger in area than the first search regions A1(t12) and A2(t12) and regions A1(t02) and A2(t02) that are centered on the positions of feature points P1 and P2 detected in the second cardiac phase.

[0073] According to the X-ray diagnostic apparatus 1 of the second embodiment, it is possible to detect the positions of feature points even in the case of a low frame rate that is susceptible to the influence of pulsation and respiratory movement, for example, and therefore the medical device 60 can be fluoroscopically viewed stably and with high visibility using X-rays.

[0074] (Third embodiment) 15 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus 1 according to the third embodiment. The third embodiment differs from the second embodiment in that a second search area different from the first search area is set when an X-ray image is generated by expanding a narrower narrow-area imaging range within the predetermined imaging range from a predetermined imaging range. In the third embodiment, after step ST13, the process proceeds to step ST30.

[0075] In step ST30, it is determined whether or not the predetermined imaging range has been changed to a narrower narrow imaging range within the predetermined imaging range (in other words, whether or not the display mode has been changed to an enlarged display mode). The information acquisition function F5 acquires information about imaging conditions for acquiring X-ray data for generating an X-ray image.

[0076] If an X-ray image is to be generated by expanding a narrower narrow imaging range within the predetermined imaging range from the predetermined imaging range (i.e., if YES in step ST30), proceed to step ST15. That is, if the information acquisition function F5 acquires information that X-ray data is acquired in a narrower narrow imaging range than the predetermined imaging range, the region setting unit sets a second search region different from the first search region in the first X-ray image. If NO in step ST30, proceed to step ST17.

[0077] 16 is a diagram illustrating a plurality of consecutive frame images of X-ray fluoroscopic images of different imaging ranges. As shown in FIG. 16, when a frame image is generated by enlarging a predetermined imaging range FOV1 to a narrower narrow imaging range FOV2 within the predetermined imaging range, the movement distance of the medical device 60 between the previous and next frame images becomes relatively large on the display. Therefore, the position of a feature point may not be detected in the predetermined search area.

[0078] 16, for example, in the case of a predetermined shooting range FOV1, feature points P1 and P2 are depicted within search areas A1(t03) and A2(t03) on the frame image Im(t03). On the other hand, when a narrower narrow shooting range FOV2 within the predetermined shooting range is enlarged, feature points P1 and P2 are not depicted within search areas A1(t13) and A2(t13) on the frame image Im(t13).

[0079] Fig. 17 is a diagram illustrating an example of setting a second search region in the third embodiment. Fig. 17 shows plan views of a frame image Im(t03) in a past cardiac cycle and a frame image Im(t13) in a current cardiac cycle in Fig. 16. As shown in Fig. 17, the region setting function F3 may set regions A1(t03) and A2(t03) as the second search region, with the positions of feature points P1 and P2 detected in the second cardiac phase as their centers. The region setting function F3 may set regions D1(t03) and D2(t03) as the second search region, with the positions of feature points P1 and P2 detected in the second cardiac phase as their centers, so that the areas of the first search regions A1(t13) and A2(t13) are larger than those of the first search regions A1(t13) and A2(t13).

[0080] Furthermore, the region setting function F3 may set, as the second search region, a region that is the union of the first search regions A1(t13) and A2(t13) and regions A1(t03) and A2(t03) that are centered on the positions of the feature points P1 and P2 detected in the second cardiac phase. The region setting function F3 may set, as the second search region, a region that is the union of regions D1(t03) and D2(t03) that are larger in area than the first search regions A1(t13) and A2(t13) and regions A1(t03) and A2(t03) that are centered on the positions of the feature points P1 and P2 detected in the second cardiac phase.

[0081] Furthermore, when the imaging range of the second X-ray image is narrower than the imaging range of the first X-ray image, the region setting function F3 may set the second search region in a region that takes into account the rate of change of the imaging range of the second X-ray image relative to the imaging range of the first X-ray image. For example, when the rate of change of the imaging range of the second X-ray image relative to the imaging range of the first X-ray image is N%, regions E1(t13) and E2(t13) that are obtained by expanding the first search regions A1(t13) and A2(t13) by N% of the rate of change may be set as the second search region.

[0082] (Modification of the third embodiment) Fig. 18 is a diagram illustrating an imaging region for a second search region in a modified example of the third embodiment. As shown in Fig. 18, when an X-ray image is generated by expanding a narrow imaging range narrower than a predetermined imaging range and no feature point is detected, the X-ray tube 211 may irradiate X-rays so that X-ray data is collected in the entire detection range FOV3 of the X-ray detection device 22, and the feature point detection function F2 may detect the position of the feature point in the entire detection range FOV3.

[0083] According to the X-ray diagnostic apparatus 1 of the third embodiment and the modified example of the third embodiment, it is possible to detect the positions of feature points even in a situation where X-ray fluoroscopy is performed by changing the image magnification ratio, for example, by enlarging a narrow-area imaging range that is narrower than a predetermined imaging range to generate a frame image, and therefore it is possible to perform X-ray fluoroscopy of the medical device 60 stably and with high visibility.

[0084] (Fourth embodiment) FIG. 19 is a schematic diagram showing an example of the detailed configuration of an X-ray diagnostic apparatus 1 according to a fourth embodiment. The fourth embodiment differs from the first embodiment in that a blood vessel detection function F6 is further implemented. FIG. 20 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus 1 according to the fourth embodiment. In the fourth embodiment, if the position of a feature point is detected in the first search area in the first X-ray image (i.e., YES in step ST14), the process proceeds to step ST17. If the feature point is not detected (i.e., NO in step ST14), the process proceeds to step ST40.

[0085] In step ST40, the blood vessel detection function F6 detects a blood vessel running region F of the blood vessel through which the medical device 60 passes. For example, the blood vessel running region F of the subject during the procedure is detected from an X-ray fluoroscopic image of the blood vessel into which a contrast agent has been injected.

[0086] In step ST41, the region setting function F3 sets a second search region different from the first search region to be the union of the first search region and the blood vessel running region F. After step ST41, the process proceeds to step ST16.

[0087] Fig. 21 is a diagram illustrating an example of setting the second search region in the fourth embodiment. Fig. 21 is a plan view of the frame image Im(t12) in the current cardiac cycle in Fig. 6. As shown in Fig. 21, the union of the first search regions A1(t12) and A2(t12) and the blood vessel running region F may be set as the second search region.

[0088] According to the X-ray diagnostic apparatus 1 of the fourth embodiment, the second search area is set without using the positions of feature points in past X-ray images. Furthermore, since the second search area is set as the union of the first search area and the blood vessel running area, it becomes possible to detect the positions of feature points, and the medical device 60 can be fluoroscopically viewed stably and with high visibility.

[0089] (Fifth embodiment) 22 is a flowchart showing an example of the operation of the X-ray diagnostic apparatus 1 according to the fifth embodiment. In the fifth embodiment, if the position of a feature point is detected in the first search area in the first X-ray image (i.e., YES in step ST14), the process proceeds to step ST17. If the feature point is not detected (i.e., NO in step ST14), the process proceeds to step ST50.

[0090] In step ST50, the area setting function F3 sets the second search area so that it is larger than the area of ​​the first search area. For example, the second search area may be set by expanding the search area from the first search area into a concentric circle, ellipse, or rectangle. After step ST50, the process proceeds to step ST16.

[0091] FIG. 23 is a diagram illustrating an example of setting the second search area in the fifth embodiment. Fig. 23 is a plan view of the frame image Im(t12) in the current cardiac cycle of Fig. 6. As shown in Fig. 23, regions G1(t12) and G2(t12) larger than the areas of the first search regions A1(t12) and A2(t12) may be set as second search regions.

[0092] According to the X-ray diagnostic apparatus 1 of the fifth embodiment, the second search area is set without using the positions of feature points in past X-ray images. Furthermore, since the second search area is set to an area larger than the area of ​​the first search area, it becomes possible to detect the positions of feature points, and the medical device 60 can be fluoroscopically viewed stably and with high visibility.

[0093] (Sixth embodiment) In the X-ray diagnostic apparatus 1 according to the first to third embodiments, the positions of feature points are detected in the second cardiac phase closest to the first cardiac phase in the second X-ray image corresponding to a cardiac cycle earlier than the current cardiac cycle. Therefore, it is possible to set a second search area different from the first search area based on the positions of feature points in the second cardiac phase. In the sixth embodiment, the positions of feature points in the second cardiac phase for setting the second search area are not detected. Hereinafter, the learning mode will be described, but the second search area can also be set even if feature point position detection fails a predetermined number of times in succession in the tracking mode.

[0094] 24 and 25 are diagrams illustrating an example of setting the second search area in the sixth embodiment. As shown in Fig. 24, in the learning mode, if X-ray data is acquired at a low frame rate and no feature point is detected, the X-ray data may be collected at a high frame rate higher than the low frame rate until the position of the feature point is detected. For example, if the frame rate is set to about 7 frames / sec and no feature point is detected, the frame rate may be set to about 15 frames / sec.

[0095] In this case, the X-ray data may be acquired at a high frame rate, and once the positions of the feature points are detected, the frame rate may be returned to the original low frame rate. Specifically, the controller 4 may increase the X-ray frame rate again if the detection of the positions of the feature points fails a predetermined number of times in succession. Furthermore, the controller 4 may further decrease the X-ray frame rate if the detection of the positions of the feature points succeeds a predetermined number of times in succession.

[0096] In the sixth embodiment, the examples of setting the second search area in the first, second, fourth, and fifth embodiments can also be used in combination. In Fig. 24, in a frame image Im(t33), predetermined search areas A1(t23) and A2(t23) in a frame image Im(t23) are set as second search areas to detect the positions of feature points P1 and P2.

[0097] As shown in FIG. 25, in the learning mode, an X-ray image may be generated by expanding a narrow imaging range that is narrower than a predetermined imaging range, and if the feature point is not detected, X-ray data may be collected over the entire detection range of the X-ray detection device or over a wide imaging range that is wider than the narrow imaging range until the position of the feature point is detected.

[0098] In this case, X-ray data may be acquired over the entire detection range of the X-ray detection device or over a wide-area imaging range wider than the narrow-area imaging range, and once a feature point is detected, the narrow-area imaging range may be returned to a narrower range than the original predetermined imaging range. Specifically, if the controller 4 fails to detect the position of a feature point a predetermined number of times in succession, the controller 4 may widen the imaging range of the X-ray image again. If the controller 4 succeeds in detecting the position of a feature point a predetermined number of times in succession, the controller 4 may further narrow the imaging range of the X-ray image.

[0099] In the sixth embodiment, the examples of setting the second search area in the first, third, fourth, and fifth embodiments can also be used in combination. In Fig. 25, in frame image Im(t33), areas E1(t23) and E2(t23) are set as second search areas in predetermined search areas A1(t23) and A2(t23) in frame image Im(t23) taking into account the rate of change of the shooting range of frame image Im(t33) relative to the shooting range of frame image Im(t23), and the positions of feature points P1 and P2 are detected.

[0100] According to the X-ray diagnostic apparatus 1 of the sixth embodiment, even if detection of the positions of feature points fails consecutively or the positions of feature points are not detected at all, it becomes possible to detect the positions of feature points by temporarily increasing the frame rate or widening the imaging area, and the medical device 60 can be fluoroscopically viewed stably and with high visibility using X-rays.

[0101] In the above embodiments, the term "processor" refers to circuits such as a dedicated or general-purpose CPU (Central Processing Unit), GPU (Graphics Processing Unit), or an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)).

[0102] If the processor is, for example, a CPU, the processor realizes various functions by reading and executing a program (medical information processing program) stored in a memory circuit. Alternatively, if the processor is, for example, an ASIC, instead of storing a program in a memory circuit, the function corresponding to the program is directly incorporated into the processor circuit as a logic circuit. In this case, the processor realizes various functions through hardware processing that reads and executes the program incorporated in the circuit. Alternatively, the processor can realize various functions by combining software processing and hardware processing.

[0103] In addition, although the above embodiment shows an example in which a single processor of a processing circuit realizes each function, a processing circuit may be configured by combining multiple independent processors, and each processor may realize each function. Furthermore, when multiple processors are provided, a memory circuit for storing programs may be provided separately for each processor, or a single memory circuit may collectively store programs corresponding to the functions of all processors.

[0104] In each embodiment, the image generation function F1, feature point detection function F2, area setting function F3, display control function F4, information acquisition function F5, and blood vessel detection function F6 are examples of the image generation unit, feature point detection unit, area setting unit, display control unit, information acquisition unit, and blood vessel detection unit, respectively, as defined in the claims.

[0105] As described above, the X-ray diagnostic apparatus, medical information processing apparatus, and medical information processing program of the embodiments enable stable X-ray fluoroscopy of medical devices such as stents with high visibility, even in situations involving pulsation or respiratory movement, or when X-ray fluoroscopy is performed with the image magnification ratio changed.

[0106] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0107] 1 X-ray diagnostic equipment 211 X-ray tube 22 X-ray detection device 55 Display 100 Medical information processing device F1 Image Generation Function F2 Feature point detection function F3 area setting function F4 Display Control Function F5 information acquisition function F6 Blood vessel detection function

Claims

1. an X-ray tube that irradiates X-rays onto a subject having a medical device inserted inside the body; an X-ray detection device that collects X-rays that have passed through the subject as X-ray data; an image generating unit that generates an X-ray image of the subject from the X-ray data in association with a cardiac phase; a feature point detection unit that detects positions of feature points of the medical device in a first search area, which is a predetermined search area in a first X-ray image corresponding to a current cardiac cycle among the X-ray images, for each first cardiac phase in the current cardiac cycle; a region setting unit that sets a second search region different from the first search region based on a position of the feature point detected in a second cardiac phase closest to the first cardiac phase in a second X-ray image corresponding to a cardiac cycle earlier than the current cardiac cycle, in at least one of the following cases: (a) when the feature point is not detected; (b) when the frame rate of the X-ray image changes from a first frame rate to a second frame rate lower than the first frame rate; and (c) when the X-ray image is generated by expanding a narrower narrow-area imaging range within the predetermined imaging range from a predetermined imaging range; when the second search area is set by the area setting unit, the feature point detection unit detects positions of the feature points in the second search area. X-ray diagnostic equipment.

2. a display control unit that aligns the X-ray image based on the positions of the feature points detected by the feature point detection unit and displays the aligned X-ray image.

2. The X-ray diagnostic apparatus according to claim 1.

3. an information acquisition unit that acquires information about imaging conditions for acquiring the X-ray data for generating the X-ray image; When the information acquiring unit acquires information that the X-ray data is acquired at a low frame rate, the region setting unit sets the second search region in the first X-ray image.

2. The X-ray diagnostic apparatus according to claim 1.

4. an information acquisition unit that acquires information about imaging conditions for acquiring the X-ray data for generating the X-ray image; When the information acquisition unit acquires information that the X-ray data is acquired in a narrow imaging range that is narrower than the predetermined imaging range, the region setting unit sets the second search region in the first X-ray image.

2. The X-ray diagnostic apparatus according to claim 1.

5. The region setting unit setting the second search area around the position of the feature point detected in the second cardiac phase; 2. The X-ray diagnostic apparatus according to claim 1.

6. The region setting unit setting the second search region to be larger in area than the first search region, with the position of the feature point detected in the second cardiac phase as a center; 2. The X-ray diagnostic apparatus according to claim 1.

7. The region setting unit setting, as the second search area, a region that is a union of the first search area and a region having a center at the position of the feature point detected in the second cardiac phase; 2. The X-ray diagnostic apparatus according to claim 1.

8. when the imaging range of the second X-ray image is narrower than the imaging range of the first X-ray image, the region setting unit sets the second search region to a region taking into account a rate of change of the imaging range of the second X-ray image relative to the imaging range of the first X-ray image.

2. The X-ray diagnostic apparatus according to claim 1.

9. The X-ray image is generated by expanding a narrow imaging range that is narrower than the predetermined imaging range, and if the feature point is not detected, the X-ray tube irradiates the X-rays such that the X-ray data is collected over an entire detection range of the X-ray detection device; the feature point detection unit detects the positions of the feature points in the entire detection range; 2. The X-ray diagnostic apparatus according to claim 1.

10. In a learning mode, the positions of the feature points of the medical device are detected, and then in a tracking mode, the movement of the positions of the feature points detected in the learning mode is tracked.

2. The X-ray diagnostic apparatus according to claim 1.

11. In the learning mode, when the X-ray data is acquired at a low frame rate and the feature point is not detected, the X-ray data is collected at a high frame rate that is higher than the low frame rate until the location of the feature point is detected. The X-ray diagnostic apparatus according to claim 10.

12. In the learning mode, when the narrow imaging range narrower than the predetermined imaging range is enlarged to generate the X-ray image and the feature point is not detected, The X-ray data is collected in the entire detection range of the X-ray detection device or in a wide-area imaging range wider than the narrow-area imaging range until the position of the feature point is detected. The X-ray diagnostic apparatus according to claim 10.

13. an X-ray tube that irradiates X-rays onto a subject having a medical device inserted inside the body; an X-ray detection device that collects X-rays that have passed through the subject as X-ray data; an image generating unit that generates an X-ray image of the subject from the X-ray data; a feature point detection unit that detects the positions of feature points of the medical device in a first search area that is a predetermined search area in the X-ray image; a blood vessel detection unit that detects a blood vessel running region of a blood vessel through which the medical device passes; a region setting unit that sets a union region of the first search region and the blood vessel running region as a second search region different from the first search region when the feature point is not detected; Equipped with when the second search area is set by the area setting unit, the feature point detection unit detects positions of the feature points in the second search area. X-ray diagnostic equipment.

14. an X-ray tube that irradiates X-rays onto a subject having a medical device inserted inside the body; an X-ray detection device that collects X-rays that have passed through the subject as X-ray data; an image generating unit that generates an X-ray image of the subject from the X-ray data; a feature point detection unit that detects the positions of feature points of the medical device in a first search area that is a predetermined search area in the X-ray image; an area setting unit that sets a second search area to be larger than the first search area when the feature point is not detected; when the area setting unit sets the second search area, the feature point detection unit sets the second search area so that the area is larger than the area of ​​the first search area. X-ray diagnostic equipment.

15. a feature point detection unit that detects positions of feature points of the medical device for each first cardiac phase in the current cardiac cycle in a first search area, which is a predetermined search area in a first X-ray image corresponding to the current cardiac cycle, among X-ray images generated from X-ray data obtained by irradiating X-rays on a subject with a medical device inserted inside the body and collecting X-rays that have passed through the subject, in association with cardiac phases; a region setting unit that sets a second search region different from the first search region based on a position of the feature point detected in a second cardiac phase closest to the first cardiac phase in a second X-ray image corresponding to a cardiac cycle earlier than the current cardiac cycle, in at least one of the following cases: (a) when the feature point is not detected; (b) when the frame rate of the X-ray image changes from a first frame rate to a second frame rate lower than the first frame rate; and (c) when the X-ray image is generated by expanding a narrower narrow-area imaging range within the predetermined imaging range from a predetermined imaging range; when the second search area is set by the area setting unit, the feature point detection unit detects positions of the feature points in the second search area. Medical information processing equipment.

16. On the computer, a step of irradiating X-rays onto a subject having a medical device inserted therein, and generating X-ray images of the subject in association with cardiac phases from X-ray data obtained by collecting X-rays that have passed through the subject, and detecting positions of feature points of the medical device in a first search area, which is a predetermined search area in a first X-ray image corresponding to a current cardiac cycle, for each first cardiac phase in the current cardiac cycle; setting a second search area different from the first search area based on a position of the feature point detected in a second cardiac phase closest to the first cardiac phase in a second X-ray image corresponding to a cardiac cycle earlier than the current cardiac cycle, in at least one of the following cases: (a) when the feature point is not detected; (b) when the frame rate of the X-ray image changes from a first frame rate to a second frame rate lower than the first frame rate; and (c) when the X-ray image is generated by expanding a narrower narrow-area imaging range within the predetermined imaging range from a predetermined imaging range; Detecting the position of the feature point in the second search area; A medical information processing program that executes the above.

Images