JP2015139534A - X-ray ct device and floodlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily confirm an imaging range.SOLUTION: An X-ray CT device according to an embodiment comprises an X-ray generating unit that generates an X-ray to be applied to a subject in a cone beam shape to have a predetermined width in the body axial direction of the subject, a detection unit having a plurality of rows of detection elements that detect the X-ray having passed through the subject, and a light projection unit that projects light to a position on the subject corresponding to a border of a detection range of the detection unit in the body axial direction of the subject.

Description

  Embodiments described herein relate generally to an X-ray CT apparatus and a projector.

  In recent years, there is an X-ray CT apparatus (computed tomography) that collects information inside a subject with a gantry device and generates a medical image by imaging the inside of the subject based on the collected information. In this X-ray CT apparatus, an imaging range (FOV: Field Of View) is positioned when imaging is performed. In the case of conventional scanning (non-helical scanning), light indicating the center position of the tomographic plane is projected onto the subject by a projector to perform tomographic positioning. In the case of helical scanning, since the imaging range is wide, the imaging start position and end position are designated on a scanogram obtained by X-ray fluoroscopy (scano imaging) within a predetermined range in the body axis direction of the subject. The shooting range is positioned.

  However, with the advent of multi-slice detectors, the imaging range in one conventional scan has expanded, and volume data having a width of about 16 cm, for example, can be obtained in one conventional scan. In some cases, the photographing range in the conventional scan cannot be easily confirmed only with the light indicating the center position of the image. In addition, when the imaging range is confirmed using scano imaging, the number of imaging man-hours and exposure due to scano imaging, which are not positioned in the conventional conventional scan, are increased.

JP 2012-187322 A

  The problem to be solved by the present invention is to provide an X-ray CT apparatus and a projector capable of easily confirming an imaging range.

  An X-ray CT apparatus according to an embodiment includes an X-ray generation unit, a detection unit, and a light projecting unit. The X-ray generation unit generates X-rays irradiated to the subject in a cone beam shape having a predetermined width in the body axis direction of the subject. The detection unit includes a plurality of rows of detection elements that detect X-rays transmitted through the subject. The light projecting unit projects light to a position on the subject corresponding to the boundary of the detection range of the detection unit in the body axis direction of the subject.

FIG. 1 is a diagram illustrating the configuration of the X-ray CT apparatus according to the embodiment. FIG. 2 is a perspective view illustrating an outline of the internal structure of the gantry device. FIG. 3 is a three-side view of the projector. FIG. 4 is a perspective view of the projector. FIG. 5 is a diagram for explaining confirmation of the imaging range in the subject. FIG. 6 is a flowchart showing an example of the operation of the X-ray CT apparatus. FIG. 7 is a perspective view of a projector according to a modification. FIG. 8 is a diagram for explaining an example of light projection on a subject by the light projector. FIG. 9 is a diagram for explaining an example of light projection on a subject by the light projector.

  Hereinafter, an X-ray CT apparatus and a projector according to embodiments will be described in detail with reference to the accompanying drawings. In the following description, common constituent elements are given common reference numerals, and redundant description is omitted.

  FIG. 1 is a diagram illustrating a configuration of an X-ray CT apparatus 1 according to the embodiment. As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a bed device 20, and a console device 30.

  The gantry device 10 is a device that collects projection data by irradiating the subject P with X-rays. The gantry controller 11, the X-ray generator 12, the X-ray detector 13, the data collector 14, A rotating frame 15, an operation console 16, and a projector 17 are provided.

  The rotating frame 15 supports the X-ray generator 12 and the X-ray detector 13 so as to face each other with the subject P interposed therebetween, and the high-speed rotation is performed in a circular orbit centered on the subject P by a gantry driving unit 11c described later. It is an annular frame that rotates in a circle. The rotating frame 15 supports a projector 17 described later at a position different from the X-ray generator 12.

  FIG. 2 is a perspective view illustrating an outline of the internal structure of the gantry device 10. More specifically, the X-ray generator 12 and the X-ray detector 13 supported by the rotating frame 15 inside the gantry device 10. FIG. 6 is a diagram illustrating the positional relationship of the projector 17. As shown in FIG. 2, the projector 17 is at a position different from that of the X-ray generator 12, for example, obliquely above the subject P when the X-ray generator 12 is at a position directly above the subject P. Is supported at the position.

  The X-ray generator 12 is an apparatus that irradiates the subject P with X-rays, and includes an X-ray tube 12a, a wedge 12b, and a collimator 12c.

  The X-ray tube 12a is a cone having a conical and pyramid-shaped spread along the body axis direction (Z-axis direction shown in FIG. 1) of the subject P due to a high voltage supplied by a high voltage generator 11a described later. It is a vacuum tube that generates X-rays in the form of a beam, and the cone beam-like X-rays are exposed to the subject P as the rotating frame 15 rotates.

  The wedge 12b is an X-ray filter for adjusting the X-ray dose of X-rays emitted from the X-ray tube 12a. The collimator 12c is a slit for narrowing down the X-ray irradiation range (width in the body axis direction) in which the X-ray dose is adjusted by the wedge 12b under the control of the collimator adjustment unit 11b described later.

  The X-ray detector 13 is a two-dimensional array type detector (surface detector) that detects X-ray intensity distribution data indicating the intensity distribution of X-rays irradiated from the X-ray generator 12 and transmitted through the subject P. A plurality of detection element arrays, which are X-ray detection elements arranged in the channel direction (Y-axis direction shown in FIG. 1), are arranged along the body axis direction (slice direction, Z-axis direction shown in FIG. 1) of the subject P. It is arranged in a column. For example, in the present embodiment, the X-ray detector 13 has detection element rows arranged in 320 rows along the body axis direction of the subject P, and has a wide range of X-ray intensity distribution data transmitted through the subject P. (For example, the maximum width is 16 cm).

  Note that a range (width in the body axis direction) in which the X-ray detector 13 detects X-ray intensity distribution data transmitted through the subject P is referred to as a detection range. This detection range is a range that can be detected by all of the detection element arrays arranged in the body axis direction of the subject P at the maximum. Further, when the X-ray irradiation range is narrowed down by the collimator 12c beyond the range that can be detected by all the detection element arrays, the X-ray irradiation range becomes the detection range of the X-ray detector 13.

  The data acquisition unit 14 is a data acquisition system (DAS), and performs projection processing and A / D conversion processing on the X-ray intensity distribution data detected by the X-ray detector 13 to generate projection data. The generated projection data is transmitted to the console device 30 described later.

  The operation console 16 is provided on both sides of the opening portion of the gantry device 10 and on the front and rear sides thereof, and accepts an operation performed by the operator while confirming the state of the subject P from both sides of the gantry device 10 (see FIG. 5). . Specifically, the operation console 16 is a boundary between turning on (projecting) the projector 17, turning it off (no projection), and a detection range of the X-ray detector 13, and indicates an upper limit and a lower limit in the body axis direction. An instruction for adjusting the projection position (width adjustment) of the projector 17, and instructions for moving, stopping, and automatically feeding the top plate 22 are received from the operator.

  The projector 17 projects light on the subject P indicating the boundary of the detection range of the X-ray detector 13 in the body axis direction of the subject P. In the example of FIG. 2, the light projecting direction is set on a member provided inside the rotating frame 15 so that the light projecting direction is the central direction of the rotating frame 15 (from the upper side to the lower side). The projector 17 may be installed outside the gantry device 10 (for example, a wall in the photographing room).

  Specifically, the projector 17 is a boundary of the detection range of the X-ray detector 13 by two light sources that project linear light along a direction orthogonal to the body axis direction, and has an upper limit in the body axis direction. And two line-shaped lights indicating the lower limit are projected. Thus, by indicating the boundary of the detection range of the X-ray detector 13 with light, the operator can easily confirm the imaging range in the conventional scan. In the present embodiment, a configuration in which two line-shaped lights indicating the boundary of the detection range of the X-ray detector 13 are projected is illustrated. However, the projector 17 is a portion equivalent to the detection range of the X-ray detector 13. In the light emitted from the point light source, light in an unnecessary direction may be shielded by a shielding plate or the like.

  FIG. 3 is a three-view diagram (front view, plan view, right side view) of the projector 17. FIG. 4 is a perspective view of the projector 17. The front surface of the projector 17 is a direction toward the subject P, and the vertical direction in the front view coincides with the body axis direction of the subject P.

  As shown in FIGS. 3 and 4, the projector 17 includes laser projectors 131 and 132 that project linear light beams L <b> 2 and L <b> 3 along a direction (cross section of the body axis) orthogonal to the body axis direction. Specifically, as shown in the plan view of FIG. 3, the laser projectors 131 and 132 project fan-shaped light parallel to the cross section of the body axis by slits or polygon mirrors.

  The laser projectors 131 and 132 are formed by a rack-and-pinion mechanism including a pinion 112 that is rotationally driven by a motor 114 and two racks 121 that move in opposite directions along the body axis direction by the rotation of the pinion 112. They are moved in opposite directions along the axial direction. That is, the width H of the laser projector 131 and the laser projector 132 in the body axis direction, and the width H (see FIG. 5) of the light beams L2 and L3 projected onto the subject P is determined by the rack and pinion mechanism. Adjusted. It should be noted that the adjustment range of the width H by the rack and pinion mechanism is the same as the maximum width of the detection range of the X-ray detector 13 at the maximum, and is 0 at the minimum, and the laser projectors 131 and 132 and the central axis 111 are arranged side by side. It may be.

  Specifically, the projector 17 is joined to the plate 101 provided with a hole 102 to be screwed to the rotary frame 15 itself or a member in the rotary frame 15, and the rack and pinion mechanism described above. And a plate member 110 to be provided. The plate member 110 is provided with a pinion 112 that is rotationally driven by a motor 114 such as a stepping motor on a central shaft 111. The extension direction of the central axis 111 is designed in advance so as to match the center of the detection range of the X-ray detector 13, and a laser projector similar to the laser projectors 131 and 132 is installed in the hollow portion inside the central axis 111. May be. When the laser projector is installed inside the central axis 111, a light beam L1 indicating the center of the detection range of the X-ray detector 13 can be projected onto the subject P as shown in the plan view of FIG.

  Note that the laser projector installed inside the central axis 111 may be a point light source indicating the center of the detection range of the X-ray detector 13. Further, by making the extension direction of the central axis 111 coincide with the center of the detection range of the X-ray detector 13, when the width H is set to 0, the light beams L 2 and L 3 are in the detection range of the X-ray detector 13. The center will be shown.

  At this time, it is desirable that the light projecting forms of the light beam L1 and the light beams L2 and L3 are different from each other. For example, the color of the light beam L1 may be red, and the color of the light beams L2 and L3 may be green. Further, when scanning in a line shape, a pattern in which the light beam L1 is always lit and a pattern in which the light beams L2 and L3 are blinked may be used. In this way, by making the light projection forms of the light beam L1 and the light beams L2 and L3 different from each other, the operator can easily identify them.

  The plate member 110 is provided with slide grooves 113 extending in the vertical direction in the vicinity of both left and right ends, and the two plate members 120 are slidably connected in the vertical direction by the slide grooves 113. The two plate members 120 are provided with a rack 121 that fits with the pinion 112, and move in opposite directions along the body axis direction by the rotation of the pinion 112. A support member 124 that supports the laser projectors 131 and 132 is fixed to the outside of the two plate members 120 by a fastener 122 and a screw 123.

  FIG. 5 is a diagram for explaining confirmation of an imaging range in the subject P. As shown in FIG. 5, the operator of the X-ray CT apparatus 1 can easily confirm the imaging range in the conventional scan based on the width H of the light beams L2 and L3 on the subject P. For example, by adjusting the width H so that the maximum width of the detection range of the X-ray detector 13 is adjusted by the operation of the operation console 16 by the operator, the detection range (imaging range) of the X-ray detector 13 is the maximum width. In this case, the imaging region can be easily confirmed.

  The gantry control unit 11 is a device that controls the operation of the gantry device 10 under the control of a scan control unit 33 to be described later, and includes a high voltage generation unit 11a, a collimator adjustment unit 11b, a gantry driving unit 11c, and a projector. Drive unit 11d.

  The high voltage generator 11a is a device that supplies a high voltage to the X-ray tube 12a. The high voltage generator 11a may be installed in the photographing room separately from the gantry device 10. The collimator adjustment unit 11b is an apparatus that adjusts the X-ray irradiation range irradiated from the X-ray generator 12 to the subject P by adjusting the aperture and position of the collimator 12c. For example, the collimator adjustment unit 11b irradiates the subject P with X-rays by adjusting the aperture of the collimator 12c to narrow the X-ray irradiation range (cone angle). The collimator adjusting unit 11b sets the aperture of the collimator 12c in accordance with the width H of the laser projectors 131 and 132 (details will be described later).

  The gantry drive unit 11 c rotates the X-ray generator 12 and the X-ray detector 13 on a circular orbit around the subject P by rotating the rotary frame 15.

  The projector driving unit 11 d controls the driving of the projector 17 based on the instruction received from the operation console 16. Specifically, the projector driving unit 11d performs ON / OFF of the light projection in the projector 17 based on instructions for turning on and off the projector 17. In addition, the projector driving unit 11 d drives the motor 114 of the projector 17 based on an instruction to adjust the projection position of the projector 17. For example, when an instruction to increase the width H of the light beams L2 and L3 projected on the subject P is received, the projector drive unit 11d drives the motor 114 to rotate the pinion 112 counterclockwise. Conversely, when receiving an instruction to reduce the width H of the light beams L2 and L3 projected on the subject P, the projector drive unit 11d drives the motor 114 to rotate the pinion 112 clockwise.

  The couch device 20 is a device on which the subject P is placed, and includes a couchtop 22 and a couch driving device 21. The top plate 22 is a plate on which the subject P is placed. The couch driving device 21 moves the subject P into the rotating frame 15 by moving the top 22 in the Z-axis direction under the instruction from the operation console 16 or the control of the scan control unit 33 described later.

  The console device 30 is a device that accepts an operation of the X-ray CT apparatus 1 by an operator and reconstructs a CT image representing the internal form of the subject P from the projection data collected by the gantry device 10. The console device 30 includes an input device 31, a display device 32, a scan control unit 33, a preprocessing unit 34, a projection data storage unit 35, an image reconstruction processing unit 36, an image storage unit 37, and system control. Part 38.

  The input device 31 includes a mouse and a keyboard used by the operator of the X-ray CT apparatus 1 to input various instructions and various settings, and transfers instructions and setting information received from the operator to the system control unit 38. .

  The display device 32 is a monitor referred to by the operator, and displays a CT image or the like to the operator under the control of the system control unit 38 or accepts various settings from the operator via the input device 31. The GUI (Graphical User Interface) is displayed.

  The preprocessing unit 34 performs correction processing such as logarithmic conversion processing, offset correction, sensitivity correction, and beam hardening correction on the projection data generated by the data collection unit 14.

  The projection data storage unit 35 stores the projection data corrected by the preprocessing unit 34. Hereinafter, “corrected projection data” stored in the projection data storage unit 35 is referred to as “corrected projection data”.

  The image reconstruction processing unit 36 reconstructs a CT image by performing back projection processing on the corrected projection data stored in the projection data storage unit 35. The image storage unit 37 stores the CT image reconstructed by the image reconstruction processing unit 36.

  The scan control unit 33 controls the operations of the gantry control unit 11, the data collection unit 14, and the bed driving device 21 under the system control unit 38. Specifically, the scan control unit 33 performs X-ray scanning by irradiating the X-ray generation device 12 continuously or intermittently while rotating the rotating frame 15. For example, the scan control unit 33 performs helical scanning in which imaging is performed by continuously rotating the rotating frame 15 while moving the top plate 22 or rotating the rotating frame 15 once or continuously while the position of the subject P is fixed. Execute a conventional scan to shoot.

  The system control unit 38 performs overall control of the X-ray CT apparatus 1 by controlling operations of the gantry device 10, the couch device 20, and the console device 30. Specifically, the system control unit 38 controls the scan control unit 33 to control scanning (conventional scan, helical scan) by the gantry device 10 and the couch device 20. Further, the system control unit 38 controls image processing in the console device 30 by controlling the preprocessing unit 34 and the image reconstruction processing unit 36. In addition, the system control unit 38 controls the display device 32 to display various images stored in the image storage unit 37.

  Here, the operator adjusts the projection position (width adjustment) of the projector 17 using the operation console 16, and confirms the imaging range in the conventional scan based on the width H of the light beams L2 and L3 on the subject P. The operation of the X-ray CT apparatus 1 when imaging the subject P (conventional scan) will be described later.

  FIG. 6 is a flowchart showing an example of the operation of the X-ray CT apparatus 1. As shown in FIG. 6, the operation console 16 accepts an operator's operation (instruction for adjusting the light projection position of the projector 17) (S <b> 10), and the projector drive unit 11 d also issues an instruction for adjustment of the light projection position of the projector 17. At the same time, the motor 114 of the projector 17 is driven (S11). Thereby, the operator sets a desired imaging range (width H) while confirming the light beams L2 and L3 on the subject P.

  Next, the collimator adjustment unit 11b calculates the slit width of the collimator 12c corresponding to the width H based on the width H set as the imaging range (S12). More specifically, the slit corresponding to the drive amount (projector drive amount) of the motor 114 from the zero point (for example, the position where the laser projectors 131 and 132 are arranged side by side) in the projector 17 and the width H at the projector drive amount. The slit width may be calculated by referring to the table data D1 in which the relationship with the width is described, in conjunction with the projector driving amount according to the projection position adjustment instruction. Alternatively, the slit width may be calculated by detecting the width H with an encoder and referring to table data describing the relationship between the width H and the slit width.

  Next, the collimator adjustment unit 11b sets the slit width calculated in S12 as the slit width in the conventional scan (S13). As a result, in the conventional scan, shooting is performed in the shooting range desired by the operator. Next, imaging (conventional scan) is performed on the subject P under the control of the scan control unit 33 (S14), the CT image is reconstructed by the image reconstruction processing unit 36, and the CT image is displayed by the display device 32. Is performed (S15).

  Note that the setting of the slit width in S13 may be reflected in a conventional scan included in a preset scan plan (EP (Expert Plan)). When reflected in the scan plan in this way, when the scan plan including the conventional scan is selected from the scan plans in which various conditions are set in advance using the input device 31 or the like, the conventional imaging range desired by the operator is selected. A scan will be performed.

(Modification)
Next, as a modification of the embodiment described above, the width H of the laser projectors 131 and 132 in the body axis direction of the projector 17 described above is fixed, and the width H of the light beams L2 and L3 projected on the subject P is fixed. The case where the length is set will be described.

  FIG. 7 is a perspective view of a projector 17a according to a modification. As shown in FIG. 7, the projector 17 a has a configuration in which the plate member 120 is fixed to the plate member 110 with a fastener 125. Thereby, the width H in the body axis direction of the laser projectors 131 and 132 becomes a fixed length.

  In this modification, it is preferable that the light beams L2 and L3 from the laser projector 131 and the laser projector 132 are fixed at a width H that indicates the maximum width of the detection range of the X-ray detector 13. In this case, the operator can easily confirm the maximum width of the detection range of the X-ray detector 13 by the light beams L2 and L3 projected from the laser projectors 131 and 132 of the projector 17a.

  When the slit of the collimator 12c is widened in the body axis direction so as to maximize the detection range of the X-ray detector 13, the difference in the optical path length due to the width of the X-ray tube 12a becomes a barrel-shaped distortion. It appears on the cone beam-shaped X-ray irradiation surface (conversely, when the slit of the collimator 12c is narrowed in the body axis direction, it appears as a pincushion-shaped distortion). Therefore, the slit shape in the laser projectors 131 and 132 may be adapted to the barrel-shaped distortion that occurs when the collimator 12c widens the slit in the body axis direction.

  FIG. 8 is a diagram illustrating an example of light projection onto the subject P by the light projector 17a. By designing the slit shape of the laser projectors 131 and 132 in accordance with the barrel-shaped distortion described above, as shown in FIG. 8, the light beam L2a along the boundary of the cone beam-shaped X-rays irradiated to the subject P , L3a can be confirmed.

  Further, when the slice thickness (width in the body axis direction) is widened so that the detection range of the X-ray detector 13 is maximized, the center of the detection range of the X-ray detector 13 and the periphery in the vertical direction in the body axis direction The difference in the length of the body axis cross section of the CT image reconstructed by the image reconstruction processing unit 36 becomes large. This is because the data for reconstructing the CT image is insufficient in the peripheral portion and the range of reconstruction is narrowed. When viewed from the upper surface of the subject P, the detection center of the X-ray detector 13 is used. Long and trapezoidal shape that is shorter around the periphery. Therefore, the slit shape in the laser projectors 131 and 132 may be adapted to the trapezoid described above.

  FIG. 9 is a diagram illustrating an example of light projection onto the subject P by the light projector 17a. By designing the slit shapes in the laser projectors 131 and 132 to match the trapezoidal shape described above, as shown in FIG. 9, by confirming the light beams L2b and L3b irradiated to the subject P, CT can be performed by conventional scanning. The range where the image is reconstructed can be easily confirmed.

  According to at least one embodiment described above, the imaging range can be easily confirmed.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit 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 equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... X-ray CT apparatus, 10 ... Base apparatus, 11 ... Base control part, 11a ... High voltage generation part, 11b ... Collimator adjustment part, 11c ... Base drive part, 11d ... Projector drive part, 12 ... X-ray generation apparatus, DESCRIPTION OF SYMBOLS 12a ... X-ray tube, 12b ... Wedge, 12c ... Collimator, 13 ... X-ray detector, 14 ... Data collection part, 15 ... Rotating frame, 16 ... Operation console, 17, 17a ... Floodlight, 20 ... Bed apparatus, 21 DESCRIPTION OF SYMBOLS ... Bed drive device, 22 ... Top plate, 30 ... Console device, 31 ... Input device, 32 ... Display device, 33 ... Scan control part, 34 ... Pre-processing part, 35 ... Projection data storage part, 36 ... Image reconstruction process 37, image storage unit, 38 ... system control unit, 101, 110, 120 ... plate material, 102 ... hole, 111 ... central axis, 112 ... pinion, 113 ... slide groove, 114 ... motor, 121 Rack, 122, 125 ... Fastener, 123 ... Screw, 124 ... Support member, 131, 132 ... Laser projector, D1 ... Table data, H ... Width, L1, L2, L2a, L2b, L3, L3a, L3b ... Light beam, P ... Subject

Claims (9)

An X-ray generator that generates X-rays to be irradiated on the subject in a cone beam shape having a predetermined width in the body axis direction of the subject;
A detection unit having a plurality of detection elements for detecting X-rays transmitted through the subject;
A light projecting unit that projects light on the subject to indicate the boundary of the detection range of the detection unit in the body axis direction of the subject;
An X-ray CT apparatus comprising: The light projecting unit projects light indicating the center of the detection range of the detection unit onto the subject.
The X-ray CT apparatus according to claim 1. The light projection forms of the light indicating the boundary of the detection range and the light indicating the center of the detection range are different from each other,
The X-ray CT apparatus according to claim 2. The light projecting unit projects light on the subject that is the boundary of the detection range and that indicates the boundary of the X-ray generated in the cone beam shape,
The X-ray CT apparatus as described in any one of Claims 1 thru | or 3. The light projecting unit emits light on the subject that is a boundary of the detection range and indicates a boundary of a range in which the image is reconstructed by a reconstruction processing unit that reconstructs an image based on the output of the detection unit. To shine
The X-ray CT apparatus as described in any one of Claims 1 thru | or 3. The light projecting unit includes two light projectors that project line-shaped light along a direction orthogonal to the body axis direction, corresponding to the boundary of the detection range.
The X-ray CT apparatus as described in any one of Claims 1 thru | or 5. The light projecting unit includes a rack and pinion mechanism having a pinion and two racks that move in opposite directions along the body axis direction by rotation of the pinion,
The two projectors are moved in opposite directions along the body axis direction by the rack and pinion mechanism.
The X-ray CT apparatus according to claim 6. An operation unit for instructing movement of the two projectors along the body axis direction;
A drive unit for driving the rack and pinion mechanism in response to the instruction,
The X-ray generation unit includes a collimator unit that adjusts the width of the X-ray generated in the shape of the cone beam in the body axis direction based on the interval in the body axis direction of the two projectors instructed to move. ,
The X-ray CT apparatus according to claim 7.   Light that is generated in a cone beam shape having a predetermined width in the body axis direction of the subject and that indicates the boundary of the detection range in the body axis direction of the detection unit that detects X-rays transmitted through the subject is applied to the subject. Floodlight projector.

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