Medical image processing apparatus, x-ray diagnostic apparatus, and medical image processing program

Abstract

To properly display a device which does not have a marker pair in an X-ray image.SOLUTION: A medical image processing apparatus according to an embodiment comprises an acquisition part, a detection part, a base point determination part, and a display control part. The acquisition part successively acquires an X-ray image including a device inserted into an analyte. The detection part detects a distal end of the device on the X-ray image. The base point determination part determines a position on the device apart from the distal end as a base point. The display control part generates an image in which the position of the base point is located at least at the same position or within a predetermined range including the position between the plurality of X-ray images, and displays the image.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In interventional radiology (IVR) of coronary arteries, there is a technique of detecting a marker pair of a catheter in a fluoroscopic X-ray image or an X-ray CT image, aligning each image so as to cancel the movement of the catheter due to heartbeat and respiration, and displaying a moving image. For example, since the heart is always moving, the catheter inserted into the heart also moves together. As an operator, since it is desired to observe the movement of the catheter due to his or her own operation, it is useful if the movement of the catheter due to heartbeat or the like can be canceled. However, this technique requires a marker pair and cannot be applied when there is no marker pair on devices such as a guide wire, a catheter, or a coil.

[0003] Also, there is a technique for improving the visibility of X-ray image data including a device regardless of the presence or absence of a marker pair. In this technique, two feature points in the X-ray image data are extracted as a substitute for the above marker pair, and the positions of a plurality of X-ray image data are corrected using the two feature points as reference points. However, in this case, the position and angle of the tip region of the guide wire are substantially fixed among a plurality of X-ray image data. Therefore, in the operation of a device where the movement of the tip such as a guide wire is important, such a display method that fixes the tip cannot be said to be appropriate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to appropriately display a device without a marker pair in an X-ray image. However, the problems to be solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. The problems corresponding to the respective effects of the respective configurations shown in the respective embodiments described later can also be positioned as other problems.

Means for Solving the Problems

[0006] The medical image processing apparatus according to the embodiment includes an acquisition unit, a detection unit, a reference point determination unit, and a display control unit. The acquisition unit sequentially acquires X-ray images including a device inserted into a subject. The detection unit detects the tip of the device on the X-ray image. The reference point determination unit determines a position on the device away from the tip as a reference point. The display control unit generates an image in which at least the position of the reference point is at the same position or within a predetermined range including the position among a plurality of X-ray images and causes the display unit to display the image.

Brief Description of the Drawings

[0007]

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Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of a medical image processing apparatus, an X-ray diagnostic apparatus, and a medical image processing program will be described in detail with reference to the drawings.

[0009] 〔First Embodiment〕 First, the first embodiment will be described. In the first embodiment, a medical information processing system including a medical image processing apparatus will be described as an example.

[0010] FIG. 1 is a block diagram showing an example of the configuration of a medical information processing system 1 according to the first embodiment. As shown in FIG. 1, the medical information processing system 1 according to the first embodiment includes an X-ray diagnostic apparatus 10, an image storage apparatus 20, and a medical image processing apparatus 30. The X-ray diagnostic apparatus 10, the image storage apparatus 20, and the medical image processing apparatus 30 are connected to each other via a network.

[0011] The X-ray diagnostic apparatus 10 collects X-ray image data from a subject P. For example, the X-ray diagnostic apparatus 10 collects a plurality of X-ray image data from the subject P and transmits the collected plurality of X-ray image data to the image storage apparatus 20 or the medical image processing apparatus 30. Note that the configuration of the X-ray diagnostic apparatus 10 will be described later.

[0012] The image storage apparatus 20 stores a plurality of X-ray image data collected by the X-ray diagnostic apparatus 10. For example, the image storage apparatus 20 is realized by a computer device such as a server device. In the present embodiment, the image storage apparatus 20 acquires a plurality of X-ray image data from the X-ray diagnostic apparatus 10 via a network and stores the acquired plurality of X-ray image data in a memory provided inside or outside the apparatus.

[0013] A medical image processing device 30 acquires a plurality of time-series X-ray image data via a network and executes various processes using the acquired plurality of X-ray image data. For example, the medical image processing device 30 is realized by a computer device such as a workstation. In the present embodiment, the medical image processing device 30 acquires a plurality of X-ray image data from an X-ray diagnostic device 10 or an image storage device 20 via a network.

[0014] As shown in FIG. 1, the medical image processing device 30 includes an input interface 31, a display 32, a memory 33, and a processing circuit 34.

[0015] The input interface 31 is realized by a trackball, a switch, a button, a mouse, a keyboard, a touch pad for performing an input operation by touching an operation surface, a touch screen in which a display screen and a touch pad are integrated, a contact input circuit using an optical sensor, a voice input circuit, etc. for performing various instructions and various settings. The input interface 31 converts the input operation received from the operator into an electrical signal and outputs it to the processing circuit 34. Note that the input interface 31 is not limited to only those having physical operation components such as a mouse and a keyboard. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the medical image processing device 30 and outputs this electrical signal to the processing circuit 34 is also included in the example of the input interface 31.

[0016] The display 32 displays various information. For example, the display 32 displays a GUI (Graphical User Interface) for receiving an operator's instruction and various X-ray image data. For example, the display 32 is a liquid crystal display or a CRT (Cathode Ray Tube) display. The display 32 is an example of a display unit.

[0017] The memory 33 is realized by, for example, a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, a hard disk, an optical disk, etc. For example, the memory 33 stores a plurality of X-ray image data acquired from the image storage device 20. Also, for example, the memory 33 stores a program for each circuit included in the medical image processing device 30 to realize its function. The memory 33 is an example of a storage unit.

[0018] The processing circuit 34 realizes the function of overall controlling the medical image processing device 30. Also, the processor of the processing circuit 34 reads and executes the medical image processing program stored in the memory 33 to realize an image acquisition function 34a, a detection function 34b, a reference point determination function 34c, a display control function 34d, a region setting function 34e, and an operation reception function 34f. These respective functions 34a - 34f are stored in the memory 33 in the form of programs.

[0019] The image acquisition function 34a includes the function of sequentially acquiring X-ray images including the device inserted into the subject P. The detection function 34b includes the function of detecting the tip of the device on the X-ray image. The reference point determination function 34c includes the function of determining a position on the device away from the tip of the device as a reference point. The display control function 34d includes the function of generating and displaying on the display 32 an image in which at least the position of the reference point of the device is at the same position or within a predetermined range including the position among a plurality of X-ray images. The region setting function 34e includes the function of setting a display region for displaying at least from the tip to the reference point of the device. The operation reception function 34f includes the function of receiving an operation for changing the position of the reference point by the operator. The operator is an example of a user. Further, the display control function 34d includes the function of generating and displaying on the display 32 an image of the display region R1 so that the reference point of the device is at the same position or within a predetermined range including the position within the display region R1 for each sequentially acquired X-ray image.

[0020] In the medical image processing apparatus 30 shown in FIG. 1, each processing function is stored in the memory 33 in the form of a program executable by a computer. The processing circuit 34 is a processor that realizes the functions corresponding to the respective programs by reading and executing the programs from the memory 33. In other words, the processing circuit 34 in the state of having read each program has the functions corresponding to the read programs. In FIG. 1, although the image acquisition function 34a, the detection function 34b, the reference point determination function 34c, the display control function 34d, the region setting function 34e, and the operation reception function 34f are described as being realized by a single processing circuit 34, it is also possible to configure the processing circuit 34 by combining a plurality of independent processors, and each processor realizes the functions by executing programs.

[0021] FIG. 2 is a block diagram showing an example of the configuration of the X-ray diagnostic apparatus 10 according to the first embodiment. As shown in FIG. 2, the X-ray diagnostic apparatus 10 includes an X-ray high voltage apparatus 101, an X-ray tube 102, a collimator 103, a filter 104, a top plate 105, a C-arm 106, an X-ray detector 107, a control apparatus 108, an input interface 109, a display 110, a memory 111, and a processing circuit 112.

[0022] The X-ray high voltage apparatus 101 supplies a high voltage to the X-ray tube 102 under the control of the processing circuit 112. For example, the X-ray high voltage apparatus 101 has an electric circuit such as a transformer and a rectifier, and includes a high voltage generation apparatus that generates a high voltage to be applied to the X-ray tube 102, and an X-ray control apparatus that controls the output voltage according to the X-rays irradiated by the X-ray tube 102. Note that the high voltage generation apparatus may be a transformer type or an inverter type.

[0023] The X-ray tube 102 is a vacuum tube having a cathode (filament) that generates thermoelectrons and an anode (target) that receives the collision of the thermoelectrons and generates X-rays. The X-ray tube 102 generates X-rays by irradiating thermoelectrons from the cathode toward the anode using the high voltage supplied from the X-ray high voltage apparatus 101.

[0024] The collimator (also referred to as an X-ray aperture device) 103 has, for example, four slidable aperture vanes. The collimator 103 narrows the X-rays generated by the X-ray tube 102 by sliding the aperture vanes and irradiates the subject P. Here, the aperture vanes are plate-like members made of lead or the like, and are provided near the X-ray irradiation port of the X-ray tube 102 to adjust the X-ray irradiation range.

[0025] The filter 104 changes the quality of the X-rays transmitted depending on its material and thickness for the purpose of reducing the radiation dose to the subject P and improving the image quality of the X-ray image data, reducing the soft X-ray components that are easily absorbed by the subject P, or reducing the high-energy components that cause a decrease in the contrast of the X-ray image data. Further, the filter 104 changes the X-ray dose and irradiation range depending on its material, thickness, position, etc., and attenuates the X-rays so that the X-rays irradiated from the X-ray tube 102 to the subject P have a predetermined distribution.

[0026] The top plate 105 is a bed on which the subject P is placed and is arranged on a bed (not shown). Note that the subject P is not included in the X-ray diagnostic apparatus 10.

[0027] The C-arm 106 holds the X-ray tube 102, the collimator 103, the filter 104, and the X-ray detector 107 so as to face each other with the subject P interposed therebetween. Note that in FIG. 2, the case where the X-ray diagnostic apparatus 10 is a single plane is described as an example, but the embodiment is not limited to this, and a bi-plane case may also be possible.

[0028] The X-ray detector 107 is, for example, an X-ray flat panel detector (Flat Panel Detector: FPD) having detection elements arranged in a matrix. The X-ray detector 107 detects the X-rays irradiated from the X-ray tube 102 and transmitted through the subject P, and outputs a detection signal corresponding to the detected X-ray dose to the processing circuit 112. Note that the X-ray detector 107 may be an indirect conversion type detector having a grid, a scintillator array, and an optical sensor array, or may be a direct conversion type detector having a semiconductor element that converts the incident X-rays into an electrical signal.

[0029] The control device 108 includes a drive mechanism such as a motor and an actuator, and a circuit for controlling this mechanism. Under the control of the processing circuit 112, the control device 108 controls the operations of the collimator 103, the filter 104, the top plate 105, the C-arm 106, and the like. For example, the control device 108 controls the irradiation range of the X-rays irradiated onto the subject P by adjusting the opening degree of the aperture blades of the collimator 103. Further, the control device 108 controls the dose distribution of the X-rays irradiated onto the subject P by adjusting the position of the filter 104. Also, for example, the control device 108 rotates and moves the C-arm 106 or moves the top plate 105.

[0030] The input interface 109 is realized by a trackball, a switch, a button, a mouse, a keyboard, a touch pad for performing an input operation by touching an operation surface, a touch screen in which a display screen and a touch pad are integrated, a non-contact input circuit using an optical sensor, an audio input circuit, etc. for performing various instructions and various settings. The input interface 109 converts the input operation received from the operator into an electrical signal and outputs it to the processing circuit 112. Note that the input interface 109 is not limited to those provided with physical operation components such as a mouse and a keyboard. For example, an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the X-ray diagnostic apparatus 10 and outputs this electrical signal to the processing circuit 112 is also included in the examples of the input interface 109.

[0031] The display 110 displays various information. For example, the display 110 displays a GUI for receiving an instruction from the operator and various X-ray image data. For example, the display 110 is a liquid crystal display or a CRT display.

[0032] The memory 111 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, a hard disk, an optical disk, or the like. The memory 111 receives and stores, for example, X-ray image data collected by the processing circuit 112. Further, the memory 111 stores programs corresponding to various functions read out and executed by the processing circuit 112.

[0033] The processing circuit 112 realizes a function of overall controlling the X-ray diagnostic apparatus 10. Also, some or all of the functions 34a - 34f of the processing circuit 34 of the medical image processing apparatus 30 may be realized by the processing circuit 112 of the X-ray diagnostic apparatus 10. In the present embodiment, as shown in FIGS. 1 and 2, an example in which all of the functions 34a - 34f of the processing circuit 34 of the medical image processing apparatus 30 are also realized by the processing circuit 112 of the X-ray diagnostic apparatus 10 is shown. In this case, the processor of the processing circuit 112 reads out and executes the medical image processing program stored in the memory 111, thereby realizing the image acquisition function 112a, the detection function 112b, the reference point determination function 112c, the display control function 112d, the region setting function 112e, and the operation reception function 112f. These functions 112a - 112f are each stored in the memory 33 in the form of a program.

[0034] The image acquisition function 112a includes a function of sequentially acquiring X-ray images based on detection signals output by the X-ray detector 107, the X-ray images including a device inserted into the subject P. The detection function 112b includes a function of detecting the tip of the device on the X-ray image. The reference point determination function 112c includes a function of determining a position on the device away from the tip of the device as a reference point. The display control function 112d includes a function of generating and displaying on the display 110 an image in which at least the position of the reference point of the device is at the same position or within a predetermined range including the position among a plurality of X-ray images. The region setting function 112e includes a function of setting a display region for displaying at least from the tip to the reference point of the device. The operation reception function 112f includes a function of receiving an operation for changing the position of the reference point by the operator.

[0035] In the X-ray diagnostic apparatus 10 shown in FIG. 2, each processing function is stored in the memory 111 in the form of a program executable by a computer. The processing circuit 112 is a processor that realizes the functions corresponding to the respective programs by reading and executing the programs from the memory 111. In other words, the processing circuit 112 in the state where each program is read has the functions corresponding to the read programs. In FIG. 2, although the image acquisition function 112a, the detection function 112b, the reference point determination function 112c, the display control function 112d, the region setting function 112e, and the operation reception function 112f are described as being realized by a single processing circuit 112, the processing circuit 112 may be configured by combining a plurality of independent processors, and each processor may realize the functions by executing the programs.

[0036] As used in the above description, the term "processor" means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or a circuit such as an application specific integrated circuit (ASIC), a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). The processor realizes its functions by reading and executing a program stored in the memory 33 or the memory 111. Instead of storing the program in the memory 33 or the memory 111, it may be configured to directly incorporate the program into the circuit of the processor. In this case, the processor realizes its functions by reading and executing the program incorporated into the circuit. Note that the processor of the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as one processor by combining a plurality of independent circuits to realize its functions.

[0037] Hereinafter, the processing performed by the medical image processing apparatus 30 according to the first embodiment will be described in detail.

[0038] First, the image acquisition function 112a in the X-ray diagnostic apparatus 10 acquires a plurality of X-ray image data. For example, the image acquisition function 112a irradiates X-rays continuously or intermittently to the heart of the subject P with a device inserted into the coronary artery for a period according to an instruction from the operator. At this time, the X-ray detector 107 detects the X-rays that have passed through the heart of the subject P and outputs a detection signal corresponding to the detected X-ray dose to the processing circuit 112.

[0039] FIG. 3 is a flowchart showing an example of the processing of the medical information processing system 1 according to the first embodiment. FIG. 4 is a diagram showing an example of an X-ray image according to the first embodiment. The outline of the processing of the medical information processing system 1 will be described with reference to FIGS. 3 and 4.

[0040] In step S1, the X-ray diagnostic apparatus 10 determines whether X-ray irradiation is being performed. For example, the operation reception function 112f of the X-ray diagnostic apparatus 10 may determine whether an operation instructing X-ray imaging of the subject P has been performed on the input interface 109. Alternatively, the control device 108 of the X-ray diagnostic apparatus 10 may determine whether the X-ray tube 102 is irradiating X-rays.

[0041] If X-ray irradiation is being performed (YES in step S1), the X-ray diagnostic apparatus 10 proceeds to step S2. If X-ray irradiation is not being performed (NO in step S1), the X-ray diagnostic apparatus 10 ends the series of processes.

[0042] In step S2, the image acquisition function 112a of the X-ray diagnostic apparatus 10 generates X-ray image data based on the detection signal received from the X-ray detector 107, and stores the generated X-ray image data in the memory 111. The processing circuit 112 transmits the generated X-ray image data to the image storage device 20 or the medical image processing device 30. FIG. 4(A) shows the original X-ray image.

[0043] In step S3, the image acquisition function 34a of the medical image processing device 30 sequentially acquires X-ray image data from the X-ray diagnostic apparatus 10 or the image storage device 20, and stores the X-ray image data in the memory 33. The detection function 34b detects the tip S of the device from the X-ray image data. Here, for example, existing tip detection processing is performed (see the tip S in FIG. 4(B)).

[0044] In step S4, the detection function 34b of the medical image processing device 30 detects a device line DL which is the linear shape of the device from the X-ray image data. Here, for example, existing linear shadow detection processing is performed (refer to the device line DL in Fig. 4(C)). The details of the device line detection processing will be described later with reference to Fig. 5.

[0045] In step S5, the base point determination function 34c of the medical image processing device 30 determines the base point B of the device from the X-ray image data. The base point determination function 34c determines, in the X-ray image data, a position at a predetermined distance along the device line DL from the tip S of the detected device toward the end which is the operator's hand as the base point B (refer to the base point B in Fig. 4(D)). The details of the base point determination processing will be described later with reference to Fig. 6.

[0046] In step S6, the area setting function 34e of the medical image processing device 30 sets a display area R1 which is the area to be displayed on the display 32 in the X-ray image data. The area setting function 34e sets the display area R1 based on the positional relationship between the tip and the base point of the device for the first time. The area setting function 34e sets the display area R1 based on the position of the base point B of the device after the second time (refer to the display area R1 in Fig. 4(E)). The details of the display area setting processing will be described later with reference to Fig. 7.

[0047] In step S7, the display control function 34d of the medical image processing device 30 causes the display 32 to display an image of the set display area R1 in the X-ray image data. Specifically, the display control function 34d generates an image of the display area R1 and causes the display 32 to display it so that the base point B is located at the same position or within a predetermined range including the position within the display area R1 for each sequentially acquired X-ray image data (refer to Fig. 4(F)). As shown in Fig. 4(F), the display control function 34d may enlarge and display the image of the set display area R1.

[0048] Note that the display control function 34d may display the image of the display area R1 on the display 32 together with the X-ray image data. Specifically, the display control function 34d may display the image of the display area R1 and the X-ray image data side by side (for example, arranging FIGS. 4(E) and (F)) on the display 32. Further, the display control function 34d may display the image of the display area R1 by superimposing it on a predetermined position (for example, an area corresponding to the display area R1 in the original X-ray image) of the original X-ray image (see FIG. 4(A)) on the display 32. Also, the device line detection in step S4 may be performed, and then the device tip detection in step S3 may be performed. Furthermore, although the processing in steps S3 to S7 is described as being performed by the medical image processing apparatus 30, it may be performed by the X-ray diagnostic apparatus 10. That is, the entire processing of steps S1 to S7 may be performed by either the X-ray diagnostic apparatus 10 or the medical image processing apparatus 30.

[0049] According to the above, in each X-ray image data, the display area R1 is set based on the position of the base point B of the device, and the image of the display area R1 is displayed so that the base point B is located at the same position or within a predetermined range including the position within the display area R1. Therefore, an operator who continuously observes the images of the display area R1 generated for each sequentially acquired X-ray image can, due to the position of the base point B of the device being fixed at substantially the same position, confirm a continuous image of the device in which the tip S of the device moves in a manner reflecting the operator's intention while suppressing unnecessary movement of the device due to heartbeat or breathing. For this reason, the operator can easily confirm the movement of the tip S of the device.

[0050] FIG. 5 is a flowchart showing the device line detection process according to the first embodiment. FIG. 5 is a diagram for explaining in detail the process of step S4 in FIG. 3.

[0051] In step S11, the detection function 34b of the medical image processing apparatus 30 performs preprocessing on the X-ray image data to suppress false detection. The preprocessing includes, for example, threshold processing, noise reduction processing, frequency separation processing, and the like.

[0052] In step S12, the detection function 34b detects the device line DL from the X-ray image data by using, for example, linear shadow detection.

[0053] In step S13, the detection function 34b determines whether the device line DL is interrupted. If the device line DL is interrupted (YES in step S13), the detection function 34b proceeds to step S14. If the device line DL is not interrupted (NO in step S13), the detection function 34b ends the device line detection process.

[0054] In step S14, the detection function 34b complements the interrupted device line DL. For example, when the device line DL is interrupted due to the influence of noise or background, complementary processes such as morphological processing and spline processing are performed. Then, the detection function 34b ends the device line detection process.

[0055] Note that the detection function 34b may extract a linear shape close to the device line DL detected up to the previous X-ray image by using pattern matching processing or the like. Thereby, the accuracy of device line detection can be improved. Also, when the width of the curve assumed to be the device is a plurality of pixels, the detection function 34b may specify the device line DL by a center line formed from the center of the width of the curve, the shortest path included in the curve (for example, the inner contour of the curve with a width), or the like. Furthermore, the detection function 34b may learn the shapes of a plurality of device lines DL detected in the past by deep learning, and select the curve most likely to be the device line from a plurality of curves extracted from a new X-ray image as the device line DL.

[0056] FIG. 6 is a flowchart showing the device base point determination process according to the first embodiment. FIG. 5 is a diagram for explaining in detail the process of step S5 in FIG. 3.

[0057] In step S21, the origin determination function 34c of the medical image processing apparatus 30 preset the distance value [mm] from the tip S of the device in the memory 33. The distance value from the tip S (predetermined distance) is predetermined according to at least one of the X-ray imaging conditions and the protocol. For example, the device is determined according to the procedure to be performed next, and the distance value from the tip S to the origin B is determined according to the device. Note that the distance value set in the memory 33 may be appropriately changed by the operator. The distance value is an example of a predetermined distance.

[0058] In step S22, the origin determination function 34c reads out the predetermined distance value from the memory 33 and converts the distance value into the number of pixels on the X-ray image. The conversion rate from the distance value to the number of pixels is calculated according to the FOV (Field Of View, X-ray irradiation area), geometric magnification, digital zoom, etc. of the X-ray diagnostic apparatus 10. Geometric magnification means that the magnification rate as the X-ray image changes according to the positional relationship between the X-ray tube 102, the X-ray detector 107, and the subject P. Digital zoom is to complement the optical zoom and magnify or reduce the image by digital processing.

[0059] In step S23, the origin determination function 34c determines whether there is a deviation in the depth direction of the device line DL. The presence or absence of the deviation in the depth direction can be determined by three-dimensional information such as biplane irradiation, two-direction irradiation, and 3D volume. If there is a deviation in the depth direction (YES in step S23), the processing circuit 34 proceeds to step S24. If there is no deviation in the depth direction (NO in step S23), the processing circuit 34 proceeds to step S25.

[0060] In step S24, the origin determination function 34c corrects the number of pixels according to the deviation in the depth direction of the device line DL. When the device line is deviated in the depth direction, the number of pixels on the X-ray image becomes smaller due to being projected onto the X-ray detection surface compared with the case where it is not deviated (on the plane perpendicular to the imaging direction, that is, the plane parallel to the X-ray detection surface). Therefore, the origin determination function 34c may convert the predetermined distance into the number of pixels on the X-ray image based on the three-dimensional information of the device.

[0061] In step S25, the reference point determination function 34c determines the reference point B based on the tip S and the number of pixels. Specifically, the reference point determination function 34c traces the device line DL from the tip S to the end of the device by the number of pixels to determine the reference point B.

[0062] Note that the reference point determination function 34c may determine the first reference point (reference point B) along the device line DL from the tip S of the device, and determine a position at a distance different from the above distance value (a position farther from the tip S than the reference point B) as the second reference point. In that case, the area setting function 34e sets the display area R1 for each sequentially acquired X-ray image based on the positions of the first reference point and the second reference point. Then, the display control function 34d positions the position of the second reference point substantially at the same position in the display area R1, while changing the position of the first reference point according to the amount of variation of the tip S to generate an image of the display area R1. Thereby, the stabilization of the moving image display can be achieved.

[0063] FIG. 7 is a diagram for explaining the display area setting process according to the first embodiment. As shown in FIG. 7, the area setting function 34e sets the display area R1 such that, for example, the tip S is the center of the area and the reference point B is located at the end of the area. FIG. 7 shows an example in which the display area R1 is a square and the reference point B is located on the lower side of the square. When the display area R1 is a square, specifically, as shown in FIG. 7, the area setting function 34e first draws a horizontal straight line ln passing through the reference point B in the X-ray image. Next, from the tip S, a straight line perpendicular to the straight line ln and a straight line intersecting at 45° are drawn. Assuming that the intersections of the two straight lines and the horizontal straight line ln are points D and C respectively, a square with twice the length of the line segment CD as one side is set as the display area R1. The above is the first-time process. Assuming that the length of the line segment CD is L, in the example shown in FIG. 7, the reference point B is a point separated by Ltan20° to the left of the point D which is the midpoint of the lower side of the square.

[0064] After the second time, the image of the display area R1 is generated so that the reference point B is located at the same position within the display area R1 or within a predetermined range including the position. When the reference point B is fixed at the same position within the display area R1, when the base point determination function 34c acquires the next X-ray image, the display area R1 is set so that the reference point B is at the same position as the position of the reference point B set at the first time. At this time, the length 2L of one side of the display area R1 is maintained, and the length of the line segment BD is maintained at Ltan20°. Therefore, also in the second display area setting process, the reference point B is located at the same position as the position shown in FIG. 7 within the display area R1. On the other hand, the position of the tip S will change within the display area R1 according to the movement of the device.

[0065] Note that the base point determination function 34c may change the distance value according to the amount of change of the device in the display area R1. Also, when the inclination of the line connecting the tip S and the base point B varies greatly between X-ray images (frames), the end point of the change of the base point B (the position before or after the change) or the center point of the change may be used as the base point B. Further, when the inclination of the line connecting the tip S and the base point B varies greatly, the base point determination function 34c may propose to the operator to change the base point B to a position with less change via the display 32, and accept the change according to the input instruction from the operator.

[0066] Also, it is desirable that the display control function 34d updates the images of the tip S, the display area R1, etc. for each frame as needed with the position of the reference point B on the display area R1 fixed. Note that the display control function 34d may automatically update the images of the tip S, the display area R1, etc. at predetermined time intervals, or when the amount of change in the inclination angle of the straight line connecting the tip S and the reference point B exceeds a threshold value. Such a change in the inclination angle occurs due to a change in the position of the device within the blood vessel. Furthermore, the display control function 34d may update the images of the tip S, the display area R1, etc. according to the latest detection results corresponding to the device operation by the operator.

[0067] Furthermore, in the above description, an example in which the reference point B is located on the lower side of the square that is the display area R1 has been shown. However, depending on the positional relationship between the tip S and the reference point B, the reference point B may be located on the upper side, the right side, or the left side of the square, or the reference point B may be located at any of the four vertices of the square. Even in such cases, the same processing as described above is performed.

[0068] According to the first embodiment, even in a device such as a guide wire without a marker pair, unnecessary movements due to heartbeat and respiration can be removed. Therefore, it becomes easier to confirm the movement of the tip S of the device, and the operation of the device by the operator can be supported.

[0069] 〔Second Embodiment〕 FIG. 8 is a flowchart showing an example of the processing of the medical information processing system 1 according to the second embodiment. In the second embodiment, a region set from the X-ray image data is displayed, and the entire X-ray image data with a part thereof identified is displayed. In other words, when displaying the X-ray image data, a part thereof, that is, the tip S of the device, the device line DL, the reference point B, and the display region R1 are selectively displayed or not displayed. Note that the content overlapping with the description of FIG. 3 is omitted.

[0070] In step S31, the X-ray diagnostic apparatus 10 determines whether X-ray irradiation is being performed. If X-ray irradiation is being performed (YES in step S31), the X-ray diagnostic apparatus 10 proceeds to step S32. If X-ray irradiation is not being performed (NO in step S31), the X-ray diagnostic apparatus 10 ends the processing.

[0071] In step S32, the image acquisition function 112a of the X-ray diagnostic apparatus 10 generates X-ray image data based on the detection signal received from the X-ray detector 107, and stores the generated X-ray image data in the memory 111. The processing circuit 112 transmits the generated X-ray image data to the image storage device 20 or the medical image processing device 30.

[0072] In step S33, the image acquisition function 34a of the medical image processing apparatus 30 acquires X-ray image data from the X-ray diagnostic apparatus 10 or the image storage apparatus 20, and stores the X-ray image data in the memory 33. The detection function 34b detects the tip S of the device from the X-ray image data.

[0073] In step S34, the operation reception function 34f determines whether an operation instructing to display the tip S of the device on the entire image has been performed on the input interface 31. If there is an instruction operation for tip display (YES in step S34), the processing circuit 34 proceeds to step S35. If there is no instruction operation for tip display (NO in step S34), the processing circuit 34 proceeds to step S36.

[0074] In step S35, the processing circuit 34 identifies the detected tip S of the device among the X-ray image data stored in the memory 33. For example, as shown in FIG. 4(B), the processing circuit 34 draws a circle at the position of the tip S of the device.

[0075] In step S36, the detection function 34b of the medical image processing apparatus 30 detects the device line DL from the X-ray image data.

[0076] In step S37, the operation reception function 34f determines whether an operation instructing to display the device line on the entire image has been performed on the input interface 31. If there is an instruction operation for device line display (YES in step S37), the processing circuit 34 proceeds to step S38. If there is no instruction operation for tip display (NO in step S37), the processing circuit 34 proceeds to step S39.

[0077] In step S38, the processing circuit 34 identifies the detected device line DL among the X-ray image data stored in the memory 33. For example, as shown in FIG. 4(C), the processing circuit 34 draws a curve at the location of the device line DL.

[0078] In step S39, the reference point determination function 34c of the medical image processing apparatus 30 determines the reference point B of the device from the X-ray image data.

[0079] In step S40, the operation reception function 34f determines whether an operation instructing to display the reference point B of the device on the entire image has been performed on the input interface 31. If there is an instruction operation for reference point display (YES in step S40), the processing circuit 34 proceeds to step S41. If there is no instruction operation for reference point display (NO in step S40), the processing circuit 34 proceeds to step S42.

[0080] In step S41, the processing circuit 34 identifies the reference point B of the specified device among the X-ray image data stored in the memory 33. For example, as shown in FIG. 4(D), the processing circuit 34 draws a circle at the position of the reference point B of the device.

[0081] In step S42, the region setting function 34e sets a display region R1, which is the region to be displayed on the display 32, among the X-ray image data.

[0082] In step S43, the processing circuit 34 determines whether an operation instructing to display the display region R1 on the entire image has been performed on the input interface 31. If there is an instruction operation for region display (YES in step S43), the processing circuit 34 proceeds to step S44. If there is no instruction operation for region display (NO in step S43), the processing circuit 34 proceeds to step S45.

[0083] In step S44, the processing circuit 34 identifies the set display region R1 among the X-ray image data stored in the memory 33. For example, as shown in FIG. 4(E), the processing circuit 34 draws a thick line around the display region R1.

[0084] In step S45, the display control function 34d of the medical image processing apparatus 30 causes the image of the set display region R1 among the X-ray image data to be displayed on the display 32.

[0085] In step S46, the display control function 34d causes the X-ray image data to be displayed on the display 32. In the X-ray image data, either the tip S of the device, the device line DL, the base point B of the device, or the display area R1 may be identified, or none of them may be identified. Note that the display control function 34d may superimpose on the X-ray image data an image capable of identifying at least one of the tip S of the device, the device line DL, the base point B, and the frame of the display area R1, and cause the resulting image to be displayed on the display 32.

[0086] Note that although the processing of steps S33 to S46 has been described as being performed by the medical image processing apparatus 30, it may be performed by the X-ray diagnostic apparatus 10. That is, the X-ray diagnostic apparatus 10 may perform the entire processing of steps S31 to S46.

[0087] According to the second embodiment, it is possible to assist the operator in operating the device according to the situation of procedures such as "distance from the tip" and "enlargement of the displayed area".

[0088] 〔Third Embodiment〕 FIG. 9 is a diagram showing an example of the display area R1 according to the third embodiment. As shown in FIG. 9, when the amount of variation of the device is greater than a predetermined value, the display control function 34d of the medical image processing apparatus 30 may display a pop-up screen reading "The device has moved significantly. Do you want to change the base point? (Yes)(No)" near the display area R1 displayed on the display 32. That is, when the amount of variation of the device in the set display area R1 is greater than the threshold value, the display control function 34d causes a screen proposing a change of the base point B to be displayed on the display 32.

[0089] Furthermore, when the operator clicks "Yes", the display control function 34d may cause the mouse pointer to move only on the device line so that it is easier to change the reference point on the device line. The mouse pointer is an example of the indicated position of the pointing device. That is, when the operation reception function 34f receives an operation for changing the position of the reference point B by the operator, the display control function 34d causes the display 32 to display the position corresponding to the operation along the device line.

[0090] FIG. 10 is a diagram showing an example of X-ray image data according to the third embodiment. As shown in FIG. 10, when it is desired to expand the display range regardless of the position of the reference point B, the region setting function 34e may set an expansion region R2 separately from the display region R1 where the reference point of the device is arranged. For example, when the region setting function 34e is instructed by the operator to expand the display range of the display region R1, the region setting function 34e sets an expansion region R2 including at least a part of the display region R1. The display control function 34d causes the display 32 to display the image of the expansion region R2 in the X-ray image data together with the image of the display region R1. In this case, since the operator can easily confirm an image in a wide range including at least a part of the display region R1, the efficiency of the procedure can be improved.

[0091] 〔Fourth Embodiment〕 When detecting the tip S of the device or the device line DL, it may be possible to detect a plurality of devices. In that case, the display control function 34d of the medical image processing apparatus 30 may cause the display 32 to collectively display the images of the display regions R1 of the plurality of devices. Alternatively, the display control function 34d of the medical image processing apparatus 30 may cause the display 32 to display a screen for selecting the device targeted by the display region R1.

[0092] Also, by combining with electrocardiogram synchronous irradiation (X-ray imaging in the same phase as the heartbeat, phase synchronization), the image acquisition function 34a of the medical image processing apparatus 30 acquires an X-ray image in which the movement due to the heartbeat has almost stopped. Therefore, since there is almost no movement due to the heartbeat and only the movement due to breathing needs to be suppressed, the range in which the device fluctuates is limited, and thus it is possible to improve the accuracy of stopping unnecessary movement according to the above embodiment. Note that it may be combined with breathing synchronous irradiation.

[0093] According to at least one of the embodiments described above, a device without a marker pair can be appropriately displayed in an X-ray image.

[0094] Note that the image acquisition functions 34a and 112a are examples of an acquisition unit. The detection functions 34b and 112b are examples of a detection unit. The reference point determination functions 34c and 112c are examples of a reference point determination unit. The display control functions 34d and 112d are examples of a display control unit. The region setting functions 34e and 112e are examples of a setting unit. The operation reception functions 34f and 112f are examples of a reception unit.

[0095] Although several embodiments 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, replacements, changes, and combinations of the embodiments can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0096] 10…X-ray diagnostic apparatus 30…Medical image processing apparatus 34a, 112a…Image acquisition function 34b, 112b…Detection function 34c, 112c…Reference point determination function 34d, 112d... represent control functions 34e, 112e... area setting functions 34f, 112f... operation reception functions S... tip B... base point DL... device line R1... display area R2... extended area

Claims

1. An acquisition unit that sequentially acquires X-ray images including a device inserted into a subject; A detection unit that detects the tip of the device on the X-ray image; A reference point determination unit that determines a reference point based on a position on the device away from the tip; A display control unit that generates and causes a display unit to display an image in which at least the position of the reference point is located at the same position or within a predetermined range including the position among a plurality of X-ray images; A medical image processing apparatus comprising the above.

2. Further comprising a setting unit that sets a display area for displaying at least from the tip to the reference point of the device, The display control unit generates an image of the display area and causes the display unit to display it so that the reference point is located at the same position or within a predetermined range including the position within the display area for each sequentially acquired X-ray image. The medical image processing apparatus according to claim 1.

3. The display control unit superimposes the image of the display area on a predetermined position of the X-ray image and causes the display unit to display it. The medical image processing apparatus according to claim 2.

4. The detection unit detects a device line that is a linear shape of the device from the X-ray image, The reference point determination unit sets a position at a predetermined distance along the device line from the tip as the reference point. The medical image processing apparatus according to claim 2.

5. The predetermined distance is determined in advance according to at least one of X-ray imaging conditions and protocols. The medical image processing apparatus according to claim 4.

6. The reference point determination unit converts the predetermined distance into the number of pixels on the X-ray image and determines the reference point based on the tip and the number of pixels. The medical image processing apparatus according to claim 5.

7. The reference point determination unit converts the predetermined distance into the number of pixels on the X-ray image based on the three-dimensional information of the device. The medical image processing apparatus according to claim 6.

8. The reference point determination unit changes the predetermined distance according to the amount of variation of the device in the display area. The medical image processing apparatus according to claim 4.

9. When the amount of variation of the device in the display area is greater than a threshold value, the display control unit causes the display unit to display a screen that proposes changing the reference point. The medical image processing apparatus according to claim 8.

10. Further comprising a reception unit that receives an operation for changing the position of the reference point by a user. When receiving the operation, the display control unit causes the display unit to display a position corresponding to the operation along the device line on the display unit. The medical image processing apparatus according to claim 9.

11. The display control unit causes the display unit to display, on the display unit, an image in which at least one of a tip of the device, a device line, a reference point, and a frame of the display area is made distinguishable, superimposed on the X-ray image. The medical image processing apparatus according to claim 2.

12. The reference point determination unit determines a position at a distance different from the predetermined distance along the device line from the tip as a second reference point. The setting unit sets the display area for each of the sequentially acquired X-ray images based on the positions of the reference point and the second reference point. The medical image processing apparatus according to claim 4.

13. The display control unit generates an image of the display area by causing the position of the second reference point to be substantially the same position in the display area while changing the position of the reference point according to the amount of variation of the tip. The medical image processing apparatus according to claim 12.

14. When instructed by the user to expand the display range of the display area, the setting unit sets an extended area including at least a part of the display area. The display control unit causes the display unit to display, on the display unit, an image of the extended area of the X-ray image together with the image of the display area. The medical image processing apparatus according to claim 2.

15. An X-ray tube that generates X-rays; An X-ray detector that detects X-rays irradiated from the X-ray tube and outputs a detection signal corresponding to the detected X-ray dose; An acquisition unit that sequentially acquires X-ray images based on the detection signal, the X-ray images including a device inserted into a subject; A detection unit that detects a tip of the device on the X-ray image; A reference point determination unit that determines a position on the device away from the tip as a reference point; A display control unit that performs alignment based on the positions of the tip and the reference point among a plurality of X-ray images and causes the X-ray images to be displayed on a display unit; An X-ray diagnostic apparatus comprising the above.

16. In a computer, A function of sequentially acquiring X-ray images including a device inserted into a subject; A function of detecting a tip of the device on the X-ray image; A function of determining a position on the device away from the tip as a reference point; A function of performing alignment based on the positions of the tip and the reference point among a plurality of X-ray images and causing the X-ray images to be displayed on a display unit; A medical image processing program for realizing

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