JP7076965B2 - X-ray diagnostic equipment, image processing equipment and angle measurement jig - Google Patents

Description

Embodiments of the present invention relate to an X-ray diagnostic apparatus, an image processing apparatus, and an angle measuring jig.

For example, before spinal surgery or brain surgery, CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) collects three-dimensional data near the affected area, and the direction and depth of piercing the affected area with a device such as a needle. A treatment plan including Sato is drawn up. Since many nerves run in the affected spine and head, the direction and depth of puncture must be several millimeters accurate.

After the treatment plan is formulated, the vicinity of the affected area of the subject placed on the top plate of the bed is imaged during the operation by, for example, an X-ray diagnostic device for the circulatory system, and an X-ray image is acquired in real time. In the scene of intraoperative puncture, the X-ray diagnostic apparatus synthesizes and displays the 3D volume data and the planned line of the treatment plan and the real-time X-ray image on the display.

The doctor visually recognizes the affected part of the subject and visually recognizes it with an X-ray image, and performs puncture while determining the direction and depth of puncture. Along with this, the X-ray diagnostic apparatus moves the C-arm according to the operation of the operator to image the vicinity of the affected area from an angle at which the device is imaged from directly above or from the side. The direction of puncture is determined by the X-ray image of the angle taken from directly above. The depth of puncture is determined by the X-ray image of the angle taken from the side. The angle to be imaged is generally detected as a relative angle (imaging angle) between the bed angle and the C-arm angle in the X-ray diagnostic apparatus. Regarding the detection of the imaging angle, there are various specifications (specs) for each X-ray diagnostic apparatus, as shown in the following four examples.

As a first example, there is a specification having an angle sensor that detects the angle of each axis of the C arm. Here, as the angle sensor, for example, a potentiometer, an encoder, or the like can be appropriately used.
As a second example, there is a specification without the angle sensor. In this case, a scale indicating the angle of the C arm is swayed around each axis of the C arm, and a simple angle can be measured.
As a third example, there is a specification that the C-arm and the bed communicate with each other.
As a fourth example, there is a specification that the C arm and the bed do not communicate with each other. In this case, the angle of the C arm is used as the relative angle (imaging angle) between the subject and the C arm.
On the other hand, a navigation system that can track the tip and direction of a device in real time using infrared rays is known. This navigation system is set up and used while peripheral devices such as an X-ray diagnostic device and an electric knife are placed around the bed. This navigation system, for example, outputs infrared rays from two points, detects infrared rays reflected from the device with a camera, and identifies the spatial position of the device by a triangular ranging method. After that, the navigation system manually aligns the image of the device with the 3D volume data of the preoperative plan and displays the obtained composite image. In this way, the navigation system tracks the tip and direction of the device during surgery in real time.

Japanese Unexamined Patent Publication No. 2012-115381

The X-ray diagnostic apparatus as described above usually has no particular problem, but according to the study of the present inventor, the following inconveniences occur between the case of using the navigation system and the case of using the X-ray diagnostic apparatus. be.

When using a navigation system, there is an inconvenience in that it is difficult to introduce a new navigation system because the navigation system is expensive and few hospitals own it. In addition, the navigation system is inconvenient in that if the affected area moves after the alignment, it is necessary to manually align the affected portion. In addition, the navigation system needs to be set up so that a good camera field of view can be obtained for the device while the X-ray diagnostic device and peripheral devices are arranged. However, during surgery, there are inconveniences in that it is often difficult to set up an X-ray diagnostic device or peripheral device in a position where a good camera field of view can be obtained by an operator standing around the patient. be. If the position of the camera is moved, there is also the inconvenience that positioning is required again.

On the other hand, when an X-ray diagnostic device is used, with respect to the specification that the C-arm does not have an angle sensor described in the second example above, an accurate C-arm angle cannot be detected, so that an accurate imaging angle cannot be measured. There is an inconvenience in that it is not possible to confirm the coincidence between the imaging angle and the planned line (direction) of the treatment plan.

The specification having the angle sensor described in the first example also has the same inconvenience as the second example when the reference of 0 degree is deviated and an accurate C-arm angle cannot be detected.

Regarding the specifications for communication between the C-arm and the bed described in the third example above, as in the first and second examples above, if an accurate C-arm angle cannot be detected, the C-arm angle and the bed are used. There is an inconvenience in that the relative angle (imaging angle) with respect to the angle cannot be measured accurately.

Regarding the specifications in which the C-arm and the bed do not communicate with each other as described in the fourth example above, in addition to the same inconveniences as in the first and second examples above, the top plate of the sleeper is bent or the top plate is tilted down. In this case, there is a disadvantage in that the relative angle (imaging angle) between the C-arm angle and the bed angle cannot be accurately measured.

Therefore, when an X-ray diagnostic device is used, there is a disadvantage in that an accurate imaging angle cannot be measured due to the inability to detect an accurate C-arm angle regardless of the specifications.

The purpose is to measure an accurate imaging angle with or without an angle sensor.

The X-ray diagnostic apparatus according to the embodiment includes an X-ray generation unit, a first arrangement means, an X-ray detector, a holding means, an image generation means, a marker detection means, and a derivation means.

The X-ray generating unit generates X-rays to irradiate the subject placed on the top plate.

In the first arrangement means, a plurality of markers are arranged at predetermined intervals on a first plane substantially parallel to the placement surface of the top plate in the vicinity of the subject.

The X-ray detector detects X-rays that have passed through the subject and the marker.

The holding means rotatably holds the X-ray generator and the X-ray detector.

The image generation means generates an X-ray image of the subject and the marker based on the output of the X-ray detector.

The marker detecting means detects three or more markers from the X-ray image.

The derivation means derives the imaging angle of the X-ray image based on the detection results of the three or more markers.

FIG. 1 is a schematic diagram showing the configuration of the X-ray diagnostic apparatus according to the first embodiment. FIG. 2 is a perspective view showing the configuration of the X-ray diagnostic apparatus according to the same embodiment. FIG. 3 is a perspective view for explaining the angle measuring jig in the same embodiment. FIG. 4 is a plan view for explaining the angle measuring jig in the same embodiment. FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. FIG. 6 is a schematic diagram for explaining an example of attaching / detaching the angle measuring jig in the same embodiment. FIG. 7 is a schematic diagram for explaining an example of retracting the angle measuring jig in the same embodiment. FIG. 8 is a schematic diagram for explaining another evacuation example of the angle measuring jig in the same embodiment. FIG. 9 is a flowchart for explaining the operation in the embodiment. FIG. 10 is a schematic diagram for explaining an example of the arrangement of steel balls in the same embodiment. FIG. 11 is a schematic diagram for explaining in detail an example of the arrangement of steel balls in the same embodiment. FIG. 12 is a schematic diagram for explaining the rotation of the C arm in the same embodiment. FIG. 13 is a schematic diagram for explaining the rotation direction of the C arm in the same embodiment. FIG. 14 is a schematic diagram for explaining in detail an example of deriving the imaging angle in the same embodiment. FIG. 15 is a schematic diagram showing an example of setting information in the same embodiment. FIG. 16 is a schematic diagram for explaining a modified example of the arrangement of the steel balls of the same embodiment. FIG. 17 is a schematic diagram for explaining in detail the arrangement of the steel balls in the modified example. FIG. 18 is a schematic diagram for explaining the rotation of the C arm in the modified example. FIG. 19 is a schematic diagram for explaining the rotation direction of the C arm in the modified example. FIG. 20 is a schematic diagram for explaining in detail an example of deriving the imaging angle in the modified example. FIG. 21 is a schematic diagram showing an example of setting information in the modified example. FIG. 22 is a schematic diagram showing the configuration of the image processing device and the X-ray diagnostic device according to the second embodiment.

Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiment, an X-ray diagnostic device for a circulatory device having an X-ray generator and an X-ray detector (imaging system) attached to its end and having a floor-standing C-arm as a holding portion will be described. For example, the holding portion may be a C-arm or an Ω-arm suspended from the ceiling, or may be a general-purpose X-ray diagnostic device compatible with cardiovascular diagnosis and digestive organ diagnosis. .. Further, the case where the marker is a steel ball will be described as an example, but the marker is not limited to the steel ball, and any marker having an X-ray absorbing material and shape that can be identified from the captured X-ray image. Can be used.
<First Embodiment>
1 and 2 are a schematic diagram and a perspective view showing the configuration of the X-ray diagnostic apparatus according to the first embodiment. The X-ray diagnostic apparatus 100 includes an X-ray generator 2, an X-ray detector 3, a high voltage generator 5, an image generation circuit 6, a display 7, a holding device 8, a bed portion 9, a mechanism drive unit 10, and an input interface 15. It includes a system control circuit 16, an image processing device 30, and an angle measuring jig 200.

The X-ray generation unit 2 generates X-rays to irradiate the subject 150 placed on the top plate 91 via a part of the angle measuring jig 200 and the top plate mat 93. However, a part of the angle measuring jig 200 on the top plate 91 and the top plate mat 93 are not essential and may be omitted. The X-ray generating unit 2 includes an X-ray tube and an X-ray diaphragm that forms an X-ray weight (cone beam) with respect to the X-rays emitted from the X-ray tube. The X-ray tube is a vacuum tube that generates X-rays, and the electrons emitted from the cathode (filament) are accelerated by a high voltage and collide with the tungsten anode to generate X-rays. The X-ray diaphragm is located between the X-ray tube and the subject 150, and narrows the X-ray beam emitted from the X-ray tube to the size of a predetermined irradiation field of view. An angle measuring jig (first arrangement) in which a plurality of steel balls (markers) are arranged at predetermined intervals on a first plane substantially parallel to the mounting surface of the top plate 91 in the vicinity of the subject 150. Means) 200 is provided. In this specification, the case where the first plane is located between the top plate 91 and the subject 150 is described, but the present invention is not limited to this, and the first plane is located between the subject 150 and the X-ray detector 3. You may.

The X-ray detector 3 detects the X-rays that have passed through the subject 150 and the steel ball (marker). When the steel ball of the angle measuring jig 200 is retracted from the field of view, the X-ray detector 3 detects the X-rays transmitted through the subject 150. As such an X-ray detector 3, one that directly converts X-rays into electric charges and one that converts X-rays into light and then converts them into electric charges can be used. Here, the former will be described as an example, but the latter. It doesn't matter. That is, the X-ray detector 3 according to the present embodiment is a plane detector that converts X-rays transmitted through the subject 150 into electric charges and accumulates them, and a drive pulse for reading out the electric charges accumulated in the planar detector. It has a gate driver to generate.

The plane detector is configured by arranging minute detection elements two-dimensionally, and each detection element has a photoelectric film that senses X-rays and generates an electric charge according to the incident X-ray dose, and generates an electric charge on the photoelectric film. It is equipped with a charge storage capacitor that stores the charged charge and a TFT (thin film) that reads out the charge stored in the charge storage capacitor at a predetermined timing (neither is shown). Then, the accumulated charges are sequentially read out by the drive pulse supplied by the gate driver.

The high voltage generator 5 is supplied from a high voltage generator that generates a high voltage applied between the anode and the cathode in order to accelerate thermoelectrons generated from the cathode of the X-ray tube, and a system control circuit 16. It is provided with an X-ray control unit that controls X-ray irradiation conditions such as tube current, tube voltage, irradiation time, and irradiation timing in a high voltage generator according to an instruction signal.

The image generation circuit 6 includes a projection data generation circuit (not shown), a projection data storage circuit, and an image calculation circuit. The projection data generation circuit is a charge / voltage converter that converts the charge read in parallel from the plane detector in rows or columns into a voltage, and A that converts the output of this charge / voltage converter into a digital signal. It includes a / D converter and a parallel serial converter that converts a digitally converted parallel signal into a time-series serial signal. The projection data generation circuit supplies this serial signal to the projection data storage circuit as time-series projection data. The projection data storage circuit sequentially stores the time-series projection data supplied from the projection data generation circuit to generate two-dimensional projection data. The image calculation circuit performs image processing such as filtering processing on the two-dimensional projection data generated by the projection data storage circuit to generate image data, and further performs synthesis processing and subtraction on the obtained plurality of image data. (Subtraction) Performs processing, etc. Here, the image generation circuit 6 constitutes an image generation means for generating an X-ray image of the subject 150 and the steel ball (marker) based on the output of the X-ray detector. When the steel ball of the angle measuring jig 200 is retracted from the field of view, the image generation circuit 6 generates an X-ray image of the subject 150 based on the output of the X-ray detector.

The display 7 is composed of a display main body that displays a medical image or the like, an internal circuit that supplies a display signal to the display main body, and peripheral circuits such as a connector and a cable that connect the display main body and the internal circuit. The internal circuit generates display data by superimposing ancillary information such as subject information and projection data generation conditions on the image data supplied from the image calculation circuit of the image generation circuit 6, and D / A conversion and TV format conversion are performed and displayed on the display body.

The holding device (holding means) 8 includes a holding unit that rotatably holds the X-ray generator 2 and the X-ray detector 3 and moves or rotates in a predetermined direction around the subject 150.

The sleeper portion 9 moves the top plate 91 on which the subject 150 is placed in a predetermined direction.

The mechanism drive unit 10 is controlled by the system control circuit 16 and supplies drive signals to each of the holding device 8 and the sleeper unit 9. Specifically, the mechanism driving unit 10 drives signals to various moving mechanism units provided in the holding device 8 in order to move the imaging system such as the X-ray generating unit 2 and the X-ray detector 3 in a desired direction. Supply. By detecting the drive signal for each moving mechanism unit of the holding device 8 (for example, counting the number of drive pulses), the system control circuit 16 can detect the position information of the imaging system. Further, the mechanism driving unit 10 supplies a driving signal to each moving mechanism unit provided in the bed unit 9 in order to move the top plate 91 on which the subject 150 is placed in a desired direction. By detecting the drive signal for the moving mechanism portion of the sleeper portion 9, the system control circuit 16 can detect the position information of the top plate 91.

Next, the configuration of the holding device 8 and the bed portion 9 and the movement or rotation of each unit constituting these will be described with reference to FIG. FIG. 2 shows a top plate 91 on which a holding device 8 having an X-ray generator 2 and an X-ray detector 3 (imaging system) attached to its ends and a C-arm as a holding portion 81 and a subject 150 are placed. The sleeper portion 9 having the The subject 150 is placed on a part of the top plate 91 via an angle measuring jig 200 and a top plate mat 93 (not shown). In FIG. 2, in order to facilitate the following explanation, the body axis direction of the subject 150 (that is, the longitudinal direction of the top plate 91) is the y-axis, and the central axis of the stand 83 for holding the holding portion (C arm) 81 (that is, the longitudinal direction of the top plate 91). The (rotational axis) direction is the z-axis, and the y-axis and the direction orthogonal to the z-axis are the x-axis.

That is, the holding portion 81 to which the X-ray generating portion 2 is attached to one end (lower end) and the X-ray detector 3 faces the other end (upper end) is the holding portion holder 82. The holding portion 81 is slidably attached to the side surface of the holding portion holder 82 in the direction of the arrow a. On the other hand, the holding portion holder 82 is rotatably attached to the stand 83 in the direction of the arrow b, and the holding portion 81 also rotates about the x-axis as the holding portion holder 82 rotates. Further, an imaging system is slidably attached to the end of the holding portion 81 in the e direction. Then, the image pickup system attached to the end of the holding portion 81 is placed on the top plate 91 by sliding the holding portion 81 in the a direction, rotating the holding portion holder 82 in the b direction, and sliding the imaging system in the e direction. It can be set in any position and direction with respect to the subject 150.

On the other hand, one end of the floor swivel arm 84 arranged on the floor surface 160 is rotatably attached to the floor surface 160 by the rotation shaft z1 (first rotation shaft), and the floor swivel arm 84 is mounted. A stand 83 is rotatably attached to the other end portion about the rotation shaft z2 (second rotation shaft). In this case, the rotation axis z1 of the floor swivel arm 84 and the rotation axis z2 of the stand 83 are both set in the z direction.

That is, the position information of the imaging system attached to both ends of the holding portion 81 includes the slide moving distance of the holding portion 81 with respect to the holding portion holder 82, the rotation angle of the holding portion holder 82 with respect to the b direction, and d of the floor swiveling arm 84. It is uniquely determined by the rotation angle with respect to the direction, the rotation angle of the stand 83 with respect to the c direction, and the slide movement distance of the imaging system with respect to the holding portion 81.

Therefore, in order to move or rotate the holding portion 81, the holding portion holder 82, the stand 83, and the floor swivel arm 84 in a predetermined direction, various moving mechanism portions (that is, the holding portion 81) of the holding device 8 are slid from the mechanism driving unit 10. The holding part slide mechanism part to be moved, the holding part holder rotating mechanism part to rotate the holding part holder 82 in the b direction, the stand rotating mechanism part to rotate the stand 83 in the c direction, and the floor swivel arm 84 in the d direction. A drive signal is supplied to each of the rotating floor swivel arm rotation mechanism unit and the image pickup system slide mechanism unit that slides the image pickup system in the e direction.

On the other hand, on the sleeper 92 of the sleeper portion 9, the horizontal movement mechanism portion for horizontally moving the top plate 91 on which the subject 150 is placed in the body axis direction (f direction) and the vertical movement for vertically moving in the g direction. A mechanical part is provided. Therefore, in order to move the top plate 91 in a predetermined direction, a drive signal is supplied from the mechanism drive unit 10 to each of the horizontal movement mechanism unit and the vertical movement mechanism unit of the sleeper unit 9.

Returning to FIG. 1, the input interface 15 inputs subject information, sets X-ray imaging conditions including X-ray irradiation conditions, inputs various command signals, and the like. The input interface 15 includes, for example, a trackball for setting an area of interest (ROI), a switch button, a mouse, a keyboard, a touch pad for performing an input operation by touching an operation surface, and a display screen and a touch pad. It is realized by an integrated touch panel display or the like. The input interface 15 is connected to the system control circuit 16, converts an input operation received from the operator into an electric signal, and outputs the input operation to the system control circuit 16. In the present specification, the input interface 15 is not limited to the one provided with physical operating parts such as a mouse and a keyboard. For example, an example of the input interface 15 includes an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the device and outputs the electric signal to a control circuit.

The system control circuit 16 includes a processor and a memory (not shown), and stores the above-mentioned various information input or set by the input interface 15 and a control program in the memory. Then, the processor comprehensively controls each unit of the X-ray diagnostic apparatus 100 based on the input information, the setting information, and the control program, and performs safe and efficient X-ray imaging on the subject 150.

In addition to this, the system control circuit 16 supplies the X-ray image generated by the image generation circuit and the position information of the holding device 8 and the bed unit 9 detected from the mechanism driving unit 10 to the image processing device 30. Not limited to this, the system control circuit 16 may include an image processing device 30. Further, when the system control circuit 16 receives a relative position (distance, angle) as an analysis result of an X-ray image from the image processing device 30, the system control circuit 16 stores the relative position in the memory and sets the relative position in the memory to the mechanism driving unit 10. Used for control of.

The image processing device 30 includes a storage circuit 31 and a processing circuit 32.

The storage circuit 31 includes a memory such as an HDD (Hard Disk Drive) for recording electrical information, and peripheral circuits such as a memory controller and a memory interface associated with the memory. The storage circuit 31 includes, for example, a program executed in the processing circuit 32, an X-ray image generated by the image generation circuit 6, data used for processing in the processing circuit 32, data in the middle of processing, data after processing, and the like. Is remembered. Here, the X-ray image is an image obtained by imaging a subject 150 and a plurality of steel balls (markers) arranged at a predetermined interval in the vicinity of the subject 150, and is a system control circuit. It is supplied from 16.

The processing circuit 32 is a processor that realizes the image analysis function 32a, the marker detection function 32b, and the derivation function 32c corresponding to the program by calling and executing the program in the storage circuit 31. Although it has been described in FIG. 1 that the image analysis function 32a, the marker detection function 32b, and the derivation function 32c are realized by a single processing circuit 32, a processing circuit is configured by combining a plurality of independent processors. , Each processor may realize each function by executing a program.

Here, the image analysis function 32a is a function for analyzing an X-ray image in the storage circuit 31, and controls the marker detection function 32b and the derivation function 32c.

The marker detection function (marker detection means) 32b detects three or more steel balls (markers) from the X-ray image. Here, as the markers in the X-ray image, for example, three or more steel balls arranged at a predetermined interval from each other on the first plane substantially parallel to the mounting surface of the top plate 91, and the first one. It may contain three or more steel balls arranged at a predetermined interval from each other on a second plane substantially parallel to the plane. In such a case, among the steel balls on the first plane and the steel balls on the second plane, the steel balls on the plane far from the X-ray detector 3 are larger than the steel balls on the plane near the X-ray detector 3. And imaged. Based on this, the steel ball on the first plane and the steel ball on the second plane may have substantially the same size as each other, and the marker detection function 32b is based on the size of the steel ball in the X-ray image. Therefore, three or more steel balls on the first plane and three or more steel balls on the second plane may be detected separately. When the steel ball on the first plane and the steel ball on the second plane have substantially the same size, the enlargement ratio changes according to the distance from the X-ray detector 3, so that the steel ball can be easily identified. However, even when the steel ball on the first plane and the steel ball on the second plane do not have substantially the same size, the marker detection function 32b is on each plane based on the size of the steel ball in the X-ray image. It is possible to distinguish and detect steel balls. For example, among the steel balls on the first plane and the steel balls on the second plane, the steel balls on the plane far from the X-ray detector 3 may be larger in size than the steel balls on the plane near the X-ray detector 3. good. Alternatively, the marker on the first plane and the marker on the second plane may have different shapes (eg, spherical shape, cubic shape). Further, the marker detection function 32b derives the first imaging angle of the X-ray image based on the detection result of the marker on the first plane, and the X-ray image is based on the detection result of the marker on the second plane. The imaging angle of the X-ray image may be derived by deriving the second imaging angle of the above and averaging the first imaging angle and the second imaging angle.

The derivation function (deriving means) 32c derives the imaging angle of the X-ray image based on the detection results of the three or more steel balls (markers). Here, the derivation function 32c derives the imaging angle of the X-ray image based on, for example, the detection result of three or more steel balls and the setting information in which the positions and imaging angles of the plurality of steel balls are preset. You may. Further, the relative position (angle, distance) between the X-ray detector 3 and the steel ball may be derived from the distortion of the triangle connecting the three steel balls and the length of the line segment.

Next, the configuration of the angle measuring jig 200 will be described with reference to FIGS. 3 to 8. The angle measuring jig 200 is used to derive the imaging angle of the X-ray image obtained by imaging the subject 150 and the marker. Specifically, as shown in FIGS. 3 to 5, the angle measuring jig 200 includes a frame 210, a fixing plate 211, a marker plate 212, a support column 220, a rod-shaped member 230, and a marker arranging plate 240. It should be noted that one of the frame 210, the fixing plate 211 and the marker plate 212, and the support column 220, the rod-shaped member 230 and the marker arranging plate 240 may be omitted.

Here, the frame 210 is arranged between the top plate 91 of the X-ray diagnostic apparatus 100 and the subject 150, and has four plate-shaped members 210a, 210b, 210c having two grooves on the inner peripheral side. It is composed of 210d.

In such a frame 210, the plate-shaped member 210d may be attached and detached, and as shown in FIG. 6, the fixing plate 211 may be fixedly held by the groove 210e. In this case, the frame 210 is movable and detachably held by the groove 210f along the direction of the short side or the long side of the marker plate 212 having a substantially square shape having substantially the same area as the fixed plate 211. You may. The width of the groove 210e for holding the fixing plate 211 may be substantially the same as the thickness of the fixing plate 211. The width of the groove 211f that movably holds the marker plate 212 may be wider than the thickness of the marker plate 212.

Alternatively, as shown in FIG. 7, the frame 210 may have the plate-shaped member 210d non-detachable and the fixing plate 211 may be fixedly held by the groove 210e. In this case, the frame 210 may movably hold the marker plate 212 in the groove 210f along the direction of the short side of the marker plate 212 having a rectangular shape having an area smaller than that of the fixed plate 211.

The fixing plate 211 is a plate-shaped member made of a material that transmits X-rays, is fixedly held by the frame 210, and receives the weight of the subject 150. The fixing plate 211 may have a substantially square shape.

Returning to FIGS. 3 to 5, the marker plate 212 is a plate-shaped member made of a material that transmits X-rays, and is interposed between the fixing plate 211 and the top plate 91 so as to be movable to the frame 210. It is held, and three or more steel balls (markers) mk11, mk12, mk13, ... Are arranged at a predetermined interval from each other. Hereinafter, the steel balls mk11, mk12, mk13, ... On the first plane PL1 in the marker plate 212 are collectively referred to as a steel ball (marker) mk1. Here, the diameter of the steel balls mk11, mk12, mk13, ... May be, for example, within the range of 1 to 2 mm. The specified interval may be, for example, within the range of 20 to 40 mm.

The support column 220 has a base end portion 220a attached to the plate-shaped member 210b along a direction orthogonal to the longitudinal direction of the plate-shaped member 210b of the frame 210. The support column 220 may have a rotation axis R1 orthogonal to the longitudinal direction of the plate-shaped member 210b of the frame 210 and may be rotatably provided around the rotation axis R1. The support column 220 may have a rotation axis R3 orthogonal to the major axis direction and the longitudinal direction of the plate-shaped member 210b at the base end portion 220a and may be rotatably provided around the rotation axis R3. The rotation axes R1 and R3 are used, for example, when the marker arrangement plate 240 is retracted from above the marker plate 212, the fixing plate 211, and the frame 210, as shown in FIGS. 7 and 8, and are not essential and are omitted. You may. For example, as shown in FIG. 6, when the support column 220 or the rod-shaped member 230 is attached or detached, the rotation shafts R1 and R3 become unnecessary.

Returning to FIGS. 3 to 5, the rod-shaped member 230 is arranged so as to face the marker plate 212, one end 230a is attached to the tip end portion 220b of the support column 220, and the rod-shaped member 230 has a longitudinal direction in a direction substantially parallel to the marker plate 212. By changing the attachment position of one end 230a of the rod-shaped member 230 according to the body thickness of the subject 150, the position of the marker arrangement plate 240 can be adjusted along the longitudinal direction (vertical direction) of the support column 220. That is, the marker placement plate 240 has a range of motion in the vertical direction in consideration of the body thickness of the subject. Further, the position of the marker arrangement plate 240 can be adjusted on the second plane PL2 along the longitudinal direction of the rod-shaped member 230. The tip portion 220b of the rod-shaped member 230 may have a rotation axis R2 orthogonal to the marker plate 212 and may be rotatably provided around the rotation axis R2. When the rotation axis R2 is provided, the marker arrangement plate 240 can move on the second plane PL2 by the rotation of the rod-shaped member 230 about the rotation axis R2.

The marker arrangement plate (marker arrangement member) 240 is arranged to face the marker plate 212 and is attached to the other end 230b of the rod-shaped member 230, and is placed at a predetermined interval on a plane (second plane PL2) substantially parallel to the marker plate 212. Three or more steel balls (markers) mk21 to mk23 are arranged with a space between them. Here, the diameters of the steel balls mk21, mk22, and mk23 may be, for example, within the range of 1 to 2 mm. The specified interval may be, for example, within the range of 20 to 40 mm. In this example, three steel balls are arranged on the marker arrangement plate 240, but the present invention is not limited to this, and four or more steel balls may be arranged on the marker arrangement plate 240. Hereinafter, the steel balls mk21 to mk23 on the second plane PL2 are collectively referred to as a steel ball (marker) mk2. In this example, three steel balls mk21 to mk23 are arranged on the circumference constituting the center line of the marker arrangement plate 240 having a substantially circular shape (ring shape). The substantially circular shape of the marker arrangement plate 240 is a shape for indicating the attachment position of the tubular member that protects the drill for puncture on the subject 150. The marker arranging member is not limited to the plate-shaped marker arranging plate 240, and any shape can be used as long as the marker is arranged. Therefore, as the marker arranging member, for example, a torus-shaped marker arranging ring may be used instead of the plate-shaped marker arranging plate 240. Further, FIGS. 4 and 5 show an example of the positional relationship between the steel balls mk21 to mk23 of the marker arrangement plate 240 and the steel balls mk11 to mk13 of the marker plate 212. Note that FIG. 4 is a schematic diagram showing the positional relationship, not a diagram showing an X-ray image. This is because the steel balls mk21 to mk23 of the marker plate 240 and the steel balls mk11 to mk13 of the marker plate 212 do not overlap in the X-ray image. This is because the projected image of the steel balls mk11 to mk13 farther from the X-ray detector 3 is enlarged than the projected image of the steel balls mk21 to mk23 closer to the X-ray detector 3 to the X-ray detector 3. This is because it is detected.

Next, the operation of the X-ray diagnostic apparatus configured as described above will be described with reference to the flowchart of FIG. 9 and the schematic views of FIGS. 10 to 15. The following description will be described by taking as an example the case where the imaging angle and the like by the X-ray diagnostic apparatus are derived prior to the procedure of puncturing the device into the gap of the spine of the subject 150.

In this example, CT imaging by a CT device (not shown) is executed in advance, and planning (puncture planning) is executed based on the obtained 3D image of the subject 150. Planning includes the designation of a path connecting the puncture site and the target site. This path indicates the direction and depth of puncture of a device such as a needle. Based on the designated path, the bed portion 9 and the holding device 8 of the X-ray diagnostic apparatus 100 are set at positions close to the imaging position of the subject 150. In the X-ray diagnostic apparatus 100, the relative positions (angles and distances) between the subject 150 placed on the top plate 91 and the holding apparatus 8 are derived (ST1 to ST6). After the derivation, the relative position of the X-ray diagnostic apparatus 100 is corrected, the steel ball (marker) is retracted, and a procedure for puncturing the device is performed.

Here, the operation of steps ST1 to ST6 for deriving the relative position will be described in detail.

In step ST1, the positions of the upper marker plate 240 and the lower marker plate 212 are manually adjusted by the operator so that three or more steel balls mk1 and mk2 are detected, respectively.

In step ST2, X-ray fluoroscopy is performed by the X-ray diagnostic apparatus 100, and an X-ray image is generated. That is, the X-ray generating unit 2 generates X-rays to irradiate the subject 150. As a result, X-rays are exposed to the subject 150 and the steel balls mk1 and mk2. The X-ray detector 53 detects the X-rays that have passed through the subject 150 and the steel balls mk1 and mk2. The image generation circuit 61 generates an X-ray image based on the output of the X-ray detector 53. The X-ray image is displayed on the display 7 and is supplied to the image processing device 30 via the system control circuit 16. The image processing device 30 stores the X-ray image in the storage circuit 31.

In step ST3, the marker detection function 32b of the processing circuit 32 detects three or more steel balls (markers) mk1 and mk2 from the X-ray image. At this time, the marker detection function 32b obtains three or more steel balls mk1 on the first plane and three or more steel balls mk2 on the second plane based on the size of the steel balls in the X-ray image. It is detected separately, and the two-dimensional coordinates (x1, y1) to (x3, y3) of the upper steel ball mk2 are derived.

In step ST4, the derivation function 32c is located at a relative position (angle) between the C arm (X-ray detector 3) as the holding portion 81 and the marker placement plate 240 from the line segment connecting the three points of the upper steel ball mk2. , Distance) is derived.

In step ST5, the same processing as in steps ST3 to ST4 is executed for the lower steel ball mk1. That is, the marker detection function 32b divides three or more steel balls mk1 on the first plane and three or more steel balls mk2 on the second plane based on the size of the steel balls in the X-ray image. It is detected separately, and the two-dimensional coordinates (x1, y1) to (x3, y3) of the lower steel ball are derived. For example, as shown in FIGS. 10 and 11, when the specified interval between two steel balls of the steel balls mk11, mk12, and mk13 is 2A, the two-dimensional coordinates (X1, Y1) of the lower steel balls mk11 to mk13. )-(X3, Y3) are derived as follows.

(X1, Y1) = (0,0)
(X2, Y2) = (X1-A, Y1-A * sqrt (3))
(X3, Y3) = (X1 + A, Y1-A * sqrt (3))
Where sqrt (3) represents the (positive) square root of 3. The two-dimensional coordinates of the steel balls mk11, mk12, and mk13 correspond to the positions of the vertices of the equilateral triangle.

Subsequently, the derivation function 32c derives the relative position (angle, distance) between the C arm as the holding portion 81 and the marker plate 212 from the line segment connecting the three points of the lower steel ball mk1. For example, the derivation function 32c performs coordinate transformation (rotation, enlargement / reduction) so that the steel balls mk12 and mk13 in the X-ray image form the above two-dimensional coordinates by affine transformation when deriving the rotation angle among the relative positions. , Translation, etc.). After that, as shown in FIG. 12, the derivation function 32c rotates the triangle connecting the two-dimensional coordinates (x1, y1) to (x3, y3) obtained by the coordinate transformation to obtain an angle θ that becomes an equilateral triangle. Derived. Since the system control circuit 16 detects the rotation direction of the C arm with respect to the X-ray image from the position information, the C arm is rotated by the rotation axis corresponding to the straight line connecting the steel balls mk12 and mk13 in the X-ray image. Let me. As shown in FIG. 13, the depth direction may be determined based on the position of the triangle formed by the upper and lower steel balls mk1 and mk2, and the rotation direction may be estimated based on the depth direction. Further, the derivation of the angle θ is based on, for example, the relationship shown in FIGS. 14 (a) and 14 (b), and as shown in FIG. 15, the setting information in which the positions of the plurality of steel balls and the imaging angle θ are preset is used. You may use it. Of the relative positions (angles, distances) between the C-arm (X-ray detector 3) and the marker plate 212, the distances are the distance between the steel balls that make up the vertices of an equilateral triangle in the X-ray image and the marker plate. Derived according to the ratio to the distance between the steel balls on 212.

In step ST6, based on the processing results of the upper and lower steel balls, the derivation function 32c averages the relative position which is the processing result of the upper steel ball mk2 and the relative position which is the processing result of the lower steel ball mk1. do. As a result, the derivation function 32c measures (derived) the relative positions of the C arm and both the marker arrangement plate 240 and the marker plate 212. After the end of step ST6, the relative position of the X-ray diagnostic apparatus 100 is corrected, the steel ball (marker) is retracted, and a procedure for puncturing the device is performed.

As described above, according to the present embodiment, a plurality of markers are arranged on a first plane substantially parallel to the mounting surface of the top plate in the vicinity of the subject at a predetermined interval from each other. X-rays that have passed through the subject and the marker are detected, and an X-ray image of the subject and the marker is generated based on the output of the X-ray detector. Three or more markers are detected from the X-ray image, and the imaging angle of the X-ray image is derived based on the detection results of the three or more markers.

Therefore, it is possible to measure an accurate imaging angle regardless of the presence or absence of the angle sensor. Supplementally, even if the C-arm is not provided with an angle sensor, the relative angle between the subject and the C-arm (X-ray detector) can be derived. As a result, the puncture direction of the device planned before the operation and the imaging direction of the X-ray image can be accurately matched, and the spine and brain surgery can be performed with peace of mind. In addition to the spine and brain surgery techniques, it is possible to accurately superimpose 3D volume data taken with a CT device or the like and real-time fluoroscopic images of X-rays. Moreover, since the navigation system is unnecessary, there is no inconvenience related to the navigation system.

Further, when the imaging angle of the X-ray image is derived based on the detection result of three or more markers and the setting information in which the positions and imaging angles of the plurality of markers are set in advance, the detected markers are detected. Based on the result, the imaging angle corresponding to the position of the marker can be easily derived.

Further, when a plurality of markers are arranged on the second plane substantially parallel to the first plane at a predetermined interval from each other, based on the X-ray image obtained by capturing the plurality of markers on the second plane, The imaging angle can be derived. Further, by arranging the steel balls on the upper and lower plates, it is possible to derive a more accurate angle.

Further, when a plurality of markers arranged in the first and second arrangement means have substantially the same size as each other, three or more markers on the first plane are based on the size of the markers in the X-ray image. The marker and three or more markers on the second plane are distinguished and detected. As a result, even when the markers are provided on different planes, the markers on each plane can be easily distinguished from the X-ray image.

Further, the first imaging angle of the X-ray image is derived based on the detection result of the marker on the first plane, and the second imaging angle of the X-ray image is derived based on the detection result of the marker on the second plane. Is derived. The imaging angle of the X-ray image is derived by averaging the first imaging angle and the second imaging angle. In this case, the accuracy of the derived imaging angle can be improved.

Further, the angle measuring jig is between a frame arranged between the top plate and the subject, a fixed plate fixedly held by the frame and receiving the weight of the subject, and between the fixed plate and the top plate. It is provided with a marker plate that is movably held in a frame via an interposition and has a plurality of markers arranged therein.

As a result, when deriving the imaging angle from the X-ray image, the marker plate is arranged so as to enter the field of view according to the angle of the arm and the position of the bed, and after the imaging angle is derived, the marker is placed so as to be out of the field of view. The board can be moved.

Further, the marker plate has a substantially square shape having substantially the same area as the fixed plate, and the frame holds the marker plate movablely and detachably along the direction of the short side or the long side of the marker plate. In this case, when the imaging angle is derived from the X-ray image, the frame holds the marker plate, and after the imaging angle is derived, the marker plate can be detached from the frame.

Alternatively, the marker plate has a rectangular shape with an area smaller than that of the fixed plate, and the frame holds the marker plate movably along the direction of the short side of the marker plate. In this case, when the imaging angle is derived from the X-ray image, the marker plate can be arranged so as to be in the field of view, and after the imaging angle is derived, the marker plate can be moved so as to be out of the field of view.

Further, the angle measuring jig includes a column, a rod-shaped member having one end attached to the tip of the column, and a marker arranging member attached to the other end of the rod-shaped member. In the marker arrangement member, three or more markers are arranged on a plane substantially parallel to the marker plate at a predetermined interval from each other. In this case, the accuracy of the derived imaging angle can be improved by arranging the marker on a plane different from the marker plate in addition to the marker plate.

<Modification example>
The first embodiment has described the case where the line connecting the steel balls mk1 and the line connecting the steel balls mk2 form an equilateral triangle, but the present invention is not limited to this, and the line connecting the steel balls constitutes another shape. It may be transformed to do so. For example, the line connecting the steel balls may form a quadrangle, a quadrangular cross may be formed, or a mesh having an arbitrary shape may be formed. That is, if the distance between the steel balls is a specified interval, the line connecting the steel balls can be deformed to form an arbitrary shape.

For example, FIGS. 16 to 21 show a modified example in which the line connecting the steel balls mk11 to mk14 forms a rectangular cross, unlike FIGS. 10 to 15. However, in this modification, the distance between the steel balls corresponding to the quadrangular cross (diagonal line of the square) is set to 2A for easy understanding. As such a modification, the same operation and effect can be obtained by similarly executing the first embodiment.

<Second embodiment>
FIG. 22 is a schematic diagram showing the configurations of the image processing apparatus and the X-ray diagnostic apparatus according to the second embodiment, and the same reference numerals are used for the same parts as those in the above-mentioned drawings, and duplicate description is omitted. , Mainly describes the different parts.

The second embodiment is a modification of the first embodiment, and includes an image processing device 30 as an external device of the X-ray diagnostic device 100. The image processing device 30 includes a storage circuit 31, a processing circuit 32, an input interface 33, and a communication interface 34. The storage circuit 31 and the processing circuit 32 have the same configuration as that of the first embodiment.

For example, the storage circuit 31 includes a memory such as an HDD (Hard Disk Drive) for recording electrical information, and peripheral circuits such as a memory controller and a memory interface associated with the memory. The storage circuit 31 includes, for example, a program executed in the processing circuit 32, an X-ray image generated by the image generation circuit 6, data used for processing in the processing circuit 32, data in the middle of processing, data after processing, and the like. Is remembered. Here, the X-ray image is an image obtained by imaging a subject 150 and a plurality of steel balls (markers) arranged at a predetermined interval in the vicinity of the subject 150, and is an X-ray diagnosis. It is supplied from the device 100 via the network and written by the communication interface 34.

Further, for example, the processing circuit 32 is a processor that realizes the image analysis function 32a, the marker detection function 32b, and the derivation function 32c corresponding to the program by calling and executing the program in the storage circuit 31. Although it has been described in FIG. 22 that the image analysis function 32a, the marker detection function 32b, and the derivation function 32c are realized by a single processing circuit 32, a processing circuit is configured by combining a plurality of independent processors. , Each processor may realize each function by executing a program.

The image analysis function 32a, the marker detection function 32b, and the derivation function 32c are the same as those in the first embodiment, respectively.

The input interface 33 has the same configuration as the input interface 15 described above, and outputs an electric signal corresponding to the operation of the operator to the processing circuit 32. However, the input interface 33 of the image processing device 30 is not essential and may be omitted. The image processing device 30 may be provided as either a server or a workstation.

The communication interface 34 is a circuit for communicating with the X-ray diagnostic apparatus 100 by wire, wirelessly, or both.

Such an image processing device 30 functions as if the image processing device 30 in the X-ray diagnostic device 100 is provided as an external device.

Along with this, the X-ray diagnostic apparatus 100 includes a communication interface 17 for communicating with the image processing apparatus 30. Other configurations are the same as in the first embodiment.

According to the above configuration, the image processing device 30 provided as an external device of the X-ray diagnostic device 100 operates in the same manner as the image processing device of the first embodiment and its modified example, and obtains the same effect. be able to.

According to at least one embodiment described above, three or more markers are detected from the X-ray image of the subject and the marker, and the imaging angle of the X-ray image is determined based on the detection results of the three or more markers. Derived. Therefore, it is possible to measure an accurate imaging angle regardless of the presence or absence of the angle sensor.

The term "processor" used in the above description refers to, for example, a CPU (central processing unit), a GPU (Graphics Processing Unit), or an application specific integrated circuit (ASIC), a programmable logic device (for example,). , Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA). The processor realizes the function by reading and executing the program stored in the storage circuit. Instead of storing the program in the storage circuit, the program may be directly embedded in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program embedded in the circuit. It should be noted that each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, and a plurality of independent circuits may be combined to form one processor to realize its function. good. Further, a plurality of components in FIG. 1 may be integrated into one processor to realize the function.

The X-ray generating unit 2 in each embodiment is an example of the X-ray generating unit within the scope of claims. The X-ray detector 3 in each embodiment is an example of an X-ray detector within the scope of claims. The holding device 8 in each embodiment is an example of holding means within the scope of claims. The projection data generation circuit 4 and the image generation circuit 6 in each embodiment are examples of image generation means within the scope of claims. The storage circuit 31 in each embodiment is an example of storage means within the scope of claims. The processing circuit 32 and the marker detection function 32b in each embodiment are examples of marker detection means within the scope of the claims. The processing circuit 32 and the derivation function 32c in each embodiment are examples of derivation means within the scope of claims. The steel balls mk1, mk2, mk11 to mk14, and mk21 to mk24 in each embodiment are examples of markers in the claims. The frame 210, the fixing plate 211, and the marker plate 212 in each embodiment are examples of the first arrangement means within the scope of the claims. The marker arranging plate 240 in each embodiment is an example of a second arranging means and a marker arranging member within the scope of claims.

Although some 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 embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

2 ... X-ray generator, 3 ... X-ray detector, 5 ... High voltage generator, 6 ... Image generation circuit, 7 ... Display, 8 ... Holding device, 9 ... Sleeper, 10 ... Mechanism drive, 15, 33 ... Input interface, 16 ... System control circuit, 17 ... Communication interface, 30 ... Image processing device, 31 ... Storage circuit, 32 ... Processing circuit, 32a ... Image analysis function, 32b ... Marker detection function, 32c ... Derivation function, 81 ... Holding part, 82 ... Holding part holder, 83 ... Stand, 84 ... Floor swivel arm, 91 ... Top plate, 92 ... Sleeper, 93 ... Top plate mat, 100 ... X-ray diagnostic device, 150 ... Subject, 160 ... Floor surface , 200 ... Angle measuring jig, 210 ... Frame, 211 ... Fixed plate, 212 ... Marker plate, 220 ... Support, 230 ... Rod-shaped member, 240 ... Marker arrangement plate, mk1, mk2, mk11 to mk14, mk21 to mk24 ... Steel ball.

Claims (11)

An X-ray generator that generates X-rays that irradiate the subject placed on the top plate,
A first arrangement means in which a plurality of markers are arranged at predetermined intervals on a first plane substantially parallel to the placement surface of the top plate in the vicinity of the subject.
An X-ray detector that detects X-rays that have passed through the subject and the marker, and
A holding means for holding the X-ray generator and the X-ray detector rotatably, and
An image generation means for generating an X-ray image of the subject and the marker based on the output of the X-ray detector, and an image generation means.
A marker detecting means for detecting three or more markers from the X-ray image,
Based on the detection results of the three or more markers, the distortion of the shape formed by the line segment connecting the three or more markers included in the detection result and the length of the line segment make it possible to obtain the X-ray image. Derivation means for deriving the imaging angle and
X-ray diagnostic apparatus. An X-ray generator that generates X-rays that irradiate the subject placed on the top plate,
A first arrangement means in which a plurality of markers are arranged at predetermined intervals on a first plane substantially parallel to the placement surface of the top plate in the vicinity of the subject.
An X-ray detector that detects X-rays that have passed through the subject and the marker, and
A holding means for holding the X-ray generator and the X-ray detector rotatably, and
An image generation means for generating an X-ray image of the subject and the marker based on the output of the X-ray detector, and an image generation means.
A marker detecting means for detecting three or more markers from the X-ray image,
A derivation means for deriving the imaging angle of the X-ray image based on the detection results of the three or more markers, and
Equipped with
The first arrangement means is
A frame placed between the top plate and the subject,
A fixing plate that is fixedly held by the frame and receives the weight of the subject,
An X -ray diagnostic apparatus comprising a marker plate interposed between the fixing plate and the top plate, which is movably held by the frame and on which the plurality of markers are arranged. The derivation means claims to derive the imaging angle of the X-ray image based on the detection result of the three or more markers and the setting information in which the positions and imaging angles of the plurality of markers are preset. 1 or the X-ray diagnostic apparatus according to claim 2. An X-ray generator that generates X-rays that irradiate the subject placed on the top plate,
A first arrangement means in which a plurality of markers are arranged at predetermined intervals on a first plane substantially parallel to the placement surface of the top plate in the vicinity of the subject.
An X-ray detector that detects X-rays that have passed through the subject and the marker, and
A holding means for holding the X-ray generator and the X-ray detector rotatably, and
An image generation means for generating an X-ray image of the subject and the marker based on the output of the X-ray detector, and an image generation means.
A marker detecting means for detecting three or more markers from the X-ray image,
A derivation means for deriving the imaging angle of the X-ray image based on the detection results of the three or more markers, and
A plurality of markers are arranged in the vicinity of the subject via the subject so as to face the first arrangement means, and a plurality of markers are arranged at predetermined intervals on a second plane substantially parallel to the first plane. Second placement means and
X -ray diagnostic apparatus. The plurality of markers arranged in the first arrangement means and the plurality of markers arranged in the second arrangement means have substantially the same size as each other.
The marker detecting means distinguishes between three or more markers on the first plane and three or more markers on the second plane based on the size of the markers in the X-ray image. The X-ray diagnostic apparatus according to claim 4. The derivation means
Based on the detection result of the marker on the first plane, the first imaging angle of the X-ray image is derived.
Based on the detection result of the marker on the second plane, the second imaging angle of the X-ray image is derived.
The X-ray diagnostic apparatus according to claim 4 or 5, wherein the imaging angle of the X-ray image is derived by averaging the first imaging angle and the second imaging angle. A plurality of markers arranged on the first plane at a predetermined interval in the vicinity of the subject and the subject, and a plurality of markers arranged at a predetermined interval on a second plane substantially parallel to the first plane. A storage means for storing an X-ray image obtained by imaging the marker of
A marker detecting means for detecting three or more markers from the X-ray image,
A derivation means for deriving the imaging angle of the X-ray image based on the detection results of the three or more markers, and
Equipped with
The marker detecting means distinguishes between three or more markers on the first plane and three or more markers on the second plane based on the size of the markers in the X-ray image.
The derivation means
Based on the detection result of the marker on the first plane, the first imaging angle of the X-ray image is derived.
Based on the detection result of the marker on the second plane, the second imaging angle of the X-ray image is derived.
By averaging the first imaging angle and the second imaging angle, the imaging angle of the X-ray image is derived.
Image processing device. A frame placed between the top plate of the X-ray diagnostic device and the subject, and
A fixing plate that is fixedly held by the frame and receives the weight of the subject,
A marker plate that is interposed between the fixing plate and the top plate and is movably held by the frame, and three or more markers are arranged at a predetermined interval from each other.
Equipped with
The frame is composed of four plate-shaped members having two grooves on the inner peripheral side, and the fixing plate is held by the groove closer to the subject among the two grooves, and the top plate is held. Hold the marker plate in the groove closer to
The fixing plate is made of a material that allows X-rays to pass through.
The marker plate is made of a material that allows X-rays to pass through, and is a plate-shaped member that is interposed between the fixing plate and the top plate and is movably held by the frame.
The marker is made of an X-ray-absorbing material that can be identified from an X-ray image obtained by imaging the subject and the marker with the X-ray diagnostic apparatus.
An angle measuring jig used to derive the imaging angle of the X-ray image. The marker plate has a substantially square shape having substantially the same area as the fixing plate, and has a substantially square shape.
The angle measuring jig according to claim 8, wherein the frame is movable and detachably holds the marker plate along the direction of the short side or the long side of the marker plate. The marker plate has a rectangular shape with an area smaller than that of the fixed plate, and has a rectangular shape.
The angle measuring jig according to claim 8, wherein the frame movably holds the marker plate along the direction of the short side of the marker plate. A support with a base end attached to the frame, and
A rod-shaped member which is arranged to face the marker plate and has one end attached to the tip of the support column and has a longitudinal direction in a direction substantially parallel to the marker plate.
A marker arrangement member is provided which is arranged to face the marker plate and is attached to the other end of the rod-shaped member, and three or more markers are arranged at predetermined intervals on a plane substantially parallel to the marker plate. The angle measuring jig according to any one of claims 8 to 10.

Images