Radiation detector and radiation imaging device

Abstract

To provide a radiation detector that can stably hold sensor panels, and a radiographic device.SOLUTION: A radiation detector comprises: a support base; sensor panels; fixing members; and contact members. The support base is formed with an attachment surface having an arc surface shape. The sensor panel has an imaging area in which a plurality of pixels for detecting radiation are arranged in a two-dimensional shape. The sensor panel is attached on its first surface to the attachment surface along the arc surface shape. The fixing member partially fixes the first surface to the attachment surface. The contact member is in contact with a second surface of the sensor panel which is on the opposite side of the first surface, and prevents the sensor panel from floating from the support base.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The technology disclosed herein relates to a radiation detector and a radiation imaging apparatus. [Background technology]

[0002] There is known a radiographic imaging device that irradiates a subject with radiation from a radiation source, detects the radiation that has passed through the subject with a radiation detector, and obtains a radiographic image of the subject. For example, Patent Document 1 discloses a computed tomography (hereinafter abbreviated as CT) device as a radiographic imaging device for imaging a subject in a standing or sitting position.

[0003] The CT device described in Patent Document 1 is equipped with a radiation detector composed of multiple CMOS (Complementary Metal Oxide Semiconductor) solid-state imaging elements. In Patent Document 1, the multiple CMOS solid-state imaging elements are arranged in the circumferential direction and / or height direction (body axis direction of the subject) of a circular ring-shaped gantry, and as a whole have an arcuate surface shape following the gantry. One CMOS solid-state imaging element has a size of, for example, 44 mm x 33 mm. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6858317 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, a sensor panel using thin film transistors (hereinafter abbreviated as TFT (Thin Film Transistor)) can be made larger in area and have a higher resolution than a CMOS type solid-state imaging element. For example, a sensor panel has a size of 17 inches (approximately 432 mm x 432 mm) and a pixel pitch of 150 μm.

[0006] Consider a case where the base material of the sensor panel is made of a bendable material such as resin, and a curved sensor panel such as the arc-shaped sensor panel described in Patent Document 1 is incorporated into a radiation detector. In this case, the sensor panel is attached to a support base made of metal or the like that is precisely machined into a curved shape. However, this attachment method may cause wrinkles in the sensor panel due to thermal expansion and contraction, or the edge of the sensor panel may lift off the support base due to differences in the thermal expansion coefficients (also called linear expansion coefficients or thermal expansion coefficients) of the sensor panel and the support base, making it difficult to hold the sensor panel stably. Since the sensor panel has a relatively large area, the above-mentioned adverse effects of heat are a major problem.

[0007] One embodiment of the technique of the present disclosure provides a radiation detector and a radiation imaging apparatus capable of stably holding a sensor panel. [Means for solving the problem]

[0008] The radiation detector of the present disclosure comprises a support base having a mounting surface with a curved shape, a sensor panel including thin film transistors and having an imaging area in which pixels that detect radiation are arranged two-dimensionally, the sensor panel having a first surface mounted on the mounting surface following the curved shape, a fixing member that partially fixes the first surface to the mounting surface, and a contact member that contacts a second surface of the sensor panel opposite the first surface.

[0009] The contact members preferably bias the sensor panel towards the mounting surface.

[0010] The sensor panel is preferably fixed to the mounting surface by a fixing member at least at a central portion of the first surface.

[0011] The sensor panel is preferably fixed to the mounting surface by fixing members at symmetrical positions around a central portion of the first surface.

[0012] It is preferable that there are a plurality of fixing members, and the fixing positions of the plurality of fixing members are arranged at equal intervals.

[0013] It is preferable that there are a plurality of fixing members, and that the sizes of the fixing areas provided by the plurality of fixing members are the same.

[0014] The fixing area provided by the fixing member preferably has a regular polygonal or circular shape.

[0015] The contact members preferably deform in response to thermal expansion and contraction of the sensor panel in a direction parallel to the mounting surface.

[0016] It is preferable that the contact member has a second length along a direction parallel to the mounting surface that is shorter than a first length along a normal direction to the mounting surface.

[0017] It is preferable that the surface of the contact member that comes into contact with the second surface has a shape that follows the curved shape.

[0018] A retaining member is provided for retaining the contact member, and the retaining member preferably has a higher rigidity than the contact member.

[0019] It is preferable that the second surface has an imaging region and a non-imaging region surrounding the imaging region where no pixels are arranged, and the contact member is in contact with the non-imaging region.

[0020] A circuit board is attached to a first side of the sensor panel, and the contact members bias the sensor panel toward the mounting surface and include a first contact member arranged on the side of the first side and a second contact member facing the first side and arranged on the side of a second side of the sensor panel to which the circuit board is not attached, and it is preferable that the first contact member has a greater biasing force than the second contact member.

[0021] A circuit board is attached to the sensor panel, and a radiation shielding member is preferably attached to the contact member for shielding the circuit board from radiation.

[0022] The substrate of the sensor panel preferably has a thickness of 100 μm or less.

[0023] It is preferable that the support base is made of metal and the base material of the sensor panel is made of resin.

[0024] It is preferable to have two or more sensor panels.

[0025] A radiographic imaging apparatus according to the present disclosure includes any one of the radiation detectors described above and a radiation source that irradiates radiation.

[0026] The apparatus comprises a circular ring-shaped frame in which a radiation detector and a radiation source are attached, the frame having a cavity in which a subject is positioned, and a rotation mechanism for rotating the frame around the subject to capture radiation images of the subject at different angles, and the curved surface shape is preferably an arc surface.

[0027] It is preferable that the imaging apparatus be a computed tomography apparatus that obtains a tomographic image of a subject based on radiation images taken at different angles.

[0028] The radiation source preferably emits a cone of radiation.

[0029] The subject is preferably positioned in the cavity in one of two positions: standing and sitting. Effect of the Invention

[0030] According to the technique of the present disclosure, it is possible to provide a radiation detector and a radiation imaging apparatus capable of stably holding a sensor panel. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view showing a CT device. [Diagram 2] FIG. 2 is a front view of the main body of the CT apparatus. [Diagram 3] FIG. 2 is a side view of the main body of the CT apparatus. [Figure 4] FIG. 2 is a top view of the main body of the CT apparatus. [Diagram 5] FIG. 2 is a front view of the main body of the CT apparatus, showing a state in which a subject is positioned in a sitting position in a wheelchair. [Figure 6] FIG. 2 is a perspective view showing a radiation source, a radiation detector, and radiation. [Figure 7] FIG. 2 is a perspective view showing the inside of the radiation detector. [Figure 8] FIG. 2 is a perspective view showing a mounting structure of a sensor panel. [Figure 9] 3 is a plan view showing a mounting structure of the sensor panel and a detailed configuration of the sensor panel. FIG. [Figure 10] FIG. 4 is a plan view showing a contact position of a contact member. [Figure 11] 11A and 11B are diagrams showing the deformation and size of a contact member. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] FIG. 2 is a block diagram showing a processing unit of a CPU of the control device. [Figure 15] FIG. 13 is a diagram showing an irradiation condition table. [Figure 16] FIG. 13 is a diagram showing an overview of a process when a scout photography instruction for performing scout photography is input. [Figure 17] 11 is a diagram showing an outline of a process when a main photography instruction for carrying out a main photography is input. FIG. [Figure 18] 1 is a flowchart showing a procedure for capturing a tomographic image by a CT apparatus. [Figure 19] FIG. 1 is a diagram showing a radiation source and a radiation detector of a conventional CT apparatus. [Figure 20] 13 is a diagram showing the effective field of view when the sensor panel has an arcuate surface and when the sensor panel has a planar surface. FIG. [Figure 21] 13A and 13B are diagrams illustrating another example of a fixing position by a fixing member. [Figure 22] 13A and 13B are diagrams illustrating another example of a fixing position by a fixing member. [Figure 23] 13A and 13B are diagrams illustrating another example of a fixing position by a fixing member. [Figure 24] 13A and 13B are diagrams illustrating another example of a fixing position by a fixing member. [Diagram 25] FIG. 13 is a diagram showing a circular fixing member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] As an example, as shown in FIG. 1, a CT device 10 is a device for obtaining a tomographic image TI (see FIG. 17) of a subject S, and is composed of a device main body 11 and a control device 12. The device main body 11 is installed, for example, in an imaging room of a medical facility. The control device 12 is installed, for example, in a control room adjacent to the imaging room. The control device 12 is a desktop personal computer, a notebook personal computer, or a tablet terminal. The CT device 10 is an example of a "radiography device" according to the technology of the present disclosure.

[0033] 1 to 4, the apparatus body 11 includes a stage 13, three support columns 14A, 14B, and 14C, and a top plate 15. The stage 13 is a flat octagonal surface. Casters 16 for transportation are attached to the four corners of the rear surface of the stage 13.

[0034] The casters 16 are provided with a rotation lock mechanism (not shown), and after the device body 11 is installed at the installation location, the rotation lock mechanism can be operated to lock the rotation of the casters 16. Alternatively, the casters 16 are removable from the stage 13, and the casters 16 can be removed after the device body 11 is installed at the installation location.

[0035] The pillars 14A to 14C have a rectangular plate-like outer shape and are erected at the four corners of the surface of the stage 13. The pillars 14A and 14C are arranged on the left and right sides of the front side of the device body 11 (left and right in front of the subject S). The pillar 14B is arranged in the center of the rear side of the device body 11 (behind the subject S). The top plate 15 is attached to the upper ends of the pillars 14A to 14C. The top plate 15 is a flat surface with an octagonal outer shape that follows the stage 13. The top plate 15 is C-shaped with a circular hole cut out in the center and a cutout in the front side of the device body 11 between the pillars 14A and 14C. In the following description, the pillars 14A to 14C will be collectively referred to as the pillar 14 unless there is a need to distinguish them.

[0036] A connecting member 17A is connected to support pillar 14A, a connecting member 17B is connected to support pillar 14B, and a connecting member 17C is connected to support pillar 14C. A frame 18 is connected to connecting members 17A to 17C. In other words, support pillars 14A to 14C and frame 18 are connected to each other via connecting members 17A to 17C. In the following description, connecting members 17A to 17C will be collectively referred to as connecting members 17 unless there is a particular need to distinguish between them.

[0037] Frame 18 has a circular ring shape. Subject S is positioned at the center C (see FIG. 4) of cavity 19 of this circular frame 18. FIGS. 1 to 4 show subject S positioned in a standing position with both hands raised above his head.

[0038] The support pillars 14 are provided with guide rails (not shown) into which the connection members 17 are fitted. The connection members 17, and therefore the frame 18, can be raised and lowered in the vertical direction along the guide rails. That is, the support pillars 14 hold the frame 18 so that it can be raised and lowered in the vertical direction. The frame 18 can also rotate around the subject S with its center C as the central axis. That is, the support pillars 14A to 14C hold the frame 18 so that it can rotate around the subject S. The height position of the frame 18 may be changed by extending and contracting the support pillars 14.

[0039] A radiation source 20 that irradiates radiation R such as X-rays and gamma rays (see FIG. 6), and a radiation detector 21 that detects radiation R are attached to the frame 18. Both the radiation source 20 and the radiation detector 21 protrude from the lower edge of the frame 18. The radiation source 20 and the radiation detector 21 are disposed in opposing positions (positions 180° apart) on the frame 18. The radiation source 20 is box-shaped, and the radiation detector 21 is pad-shaped. When viewed from a direction in which the frame 18 etc. are viewed in a plan view from above, the radiation detector 21 has an arcuate surface shape (U-shape) that follows the shape of the frame 18.

[0040] A screw shaft 22A is provided on the support 14A, a screw shaft 22B is provided on the support 14B, and a screw shaft 22C is provided on the support 14C. The screw shafts 22A to 22C have a height that reaches from the stage 13 to the top plate 15. When the screw shafts 22A to 22C rotate, the connection members 17A to 17C, and therefore the frame 18, rise and fall in the vertical direction. In the following description, the screw shafts 22A to 22C will be collectively referred to as the screw shaft 22 unless there is a particular need to distinguish between them.

[0041] Pillar 14A has an opening 23A, pillar 14B has an opening 23B, and pillar 14C has an opening 23C. The openings 23A to 23C are formed by hollowing out most of pillars 14A to 14C in a rectangular shape. Through the openings 23A to 23C, subject S can be viewed from outside device body 11. Due to the presence of openings 23A to 23C, pillars 14A to 14C appear to have two pillars in some places, but since openings 23A to 23C are connected above and below, there is actually only one pillar in total.

[0042] A touch panel display 25 is attached to the support 14A via a movable arm 24. The touch panel display 25 is operated by an operator of the CT apparatus 10, such as a radiological technologist. The touch panel display 25 also displays various types of information to the operator.

[0043] 4 in which the frame 18 etc. are viewed from above, when the position where the radiation source 20 is in front of the apparatus body 11 is defined as the 0° position, the support pillar 14A is disposed at a 60° position on a circle CC centered on the center C of the frame 18, the support pillar 14B is disposed at a 180° position on the circle CC, and the support pillar 14C is disposed at a 300° position on the circle CC. In other words, the support pillars 14A to 14C are disposed at 120° intervals on the circle CC. Note that angles such as "0°", "60°", etc. refer to "0°", "60°", etc. in the sense that they include, in addition to the exact "0°", "60°", etc., an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not contradict the spirit of the technology of the present disclosure (for example, an error of about 1% to 10%). In addition, "equally spaced" refers not only to completely "equally spaced," but also to "equally spaced" including an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not go against the spirit of the technology of the present disclosure (for example, an error of about 1% to 10%).

[0044] 1 to 4 show an example in which the subject S is positioned in the cavity 19 in a standing position with both hands raised above the head, but this is not limiting. As an example, as shown in Fig. 5, the CT device 10 can also position the subject S in a sitting position in a wheelchair 30 in the cavity 19 and capture the subject S. Note that both the subject S in a standing position and the subject S in a sitting position in the wheelchair 30 are positioned so that their front faces the 0° position.

[0045] 6, the radiation source 20 incorporates a radiation tube 35 and a radiation field lamp 36. The radiation tube 35 emits radiation R. The radiation field lamp 36 emits visible light, for example, orange light, which indicates the radiation field of the radiation R.

[0046] The radiation source 20 also has an irradiation field limiter 37. The irradiation field limiter 37 is also called a collimator, and defines the irradiation field of the radiation R to the radiation detector 21. The irradiation field limiter 37 has an entrance opening into which the radiation R from the radiation tube 35 enters and an exit opening from which the radiation R exits. For example, four shielding plates are provided near the exit opening. The shielding plates are made of a material that blocks the radiation R, such as lead. The shielding plates are arranged on each side of a rectangle, in other words, arranged in a checkered pattern, and form a rectangular irradiation opening that transmits the radiation R. The irradiation field limiter 37 changes the size of the irradiation opening by changing the position of each shielding plate, thereby changing the irradiation field of the radiation R to the radiation detector 21. Due to the action of the irradiation field limiter 37, the radiation R in a quadrangular pyramid shape is irradiated from the radiation source 20. The radiation angle θ of the radiation R is, for example, 45°.

[0047] As an example, as shown in FIG. 7, the radiation detector 21 has a housing 40 with an arc-shaped surface that follows the shape of the frame 18. The housing 40 is made of carbon, for example. Two sensor panels 41A and 41B using TFTs are housed in the housing 40. The sensor panels 41A and 41B are square-shaped with a size of, for example, 17 inches (about 432 mm×about 432 mm). Opposing sides 42A and 43A of the sensor panel 41A are bent into an arc shape that follows the shape of the frame 18. Similarly, opposing sides 42B and 43B of the sensor panel 41B are bent into an arc shape that follows the shape of the frame 18. The sensor panels 41A and 41B are overlapped at sides 44A and 44B that are not bent into an arc shape.

[0048] A readout circuit board 45A is attached to the side 42A, and a readout circuit board 45B is attached to the side 43B. Nothing is attached to the side 42B opposite to the side 43B, and to the side 43A opposite to the side 42A. The sides 42A and 43B, and thus the readout circuit boards 45A and 45B, are in a so-called two-fold symmetric relationship, in that they are in the same position when rotated 180° around the center of the radiation detector 21. The readout circuit boards 45A and 45B are an example of a "circuit board" according to the technology of the present disclosure. The sides 42A and 43B are an example of a "first side" according to the technology of the present disclosure, and the sides 42B and 43A are an example of a "second side" according to the technology of the present disclosure.

[0049] A switching circuit board 47A is attached to the side 46A opposite to the side 44A, and a switching circuit board 47B is attached to the side 46B opposite to the side 44B. The switching circuit boards 47A and 47B are also an example of the "circuit board" according to the technology of the present disclosure. The sensor panels 41A and 41B have the same basic configuration, such as the mounting structure, except that the sides to which the readout circuit boards 45A and 45B are attached are different from the sides 42A and 43B (see FIG. 10). Therefore, hereinafter, the sensor panel 41A will be mainly described. As with the supports 14A to 14C, the sensor panels 41A and 41B and the parts associated therewith may be referred to below by only the numbers, omitting "A" and "B".

[0050] As an example, as shown in FIG. 8 and FIG. 9, the sensor panel 41A is attached to the support base 50. The support base 50 is made of a metal such as aluminum or copper, and has a mounting surface 51 that is precisely machined to have a convex arc shape (U-shape) facing the opposite side to the radiation source 20, following the shape of the frame 18. The first surface 52A of the sensor panel 41A is attached to the mounting surface 51. The curvature radius of the mounting surface 51 is, for example, 500 mm. A member for shielding radiation R, such as lead (not shown), is attached to the surface of the support base 50 opposite to the mounting surface 51. Note that in FIG. 8, the switching circuit board 47A is not shown to avoid complication. Here, the "U-shape" refers to a shape in which the sensor panels 41A and 41B are entirely curved, including the imaging regions 100A and 100B (see FIG. 10) and the ends of the overlapping sides 44A and 44B. More specifically, "U-shaped" refers to a shape in which both ends protrude to one side and both ends are connected to the center by curved surfaces.

[0051] The first surface 52A of the sensor panel 41A is partially fixed to the mounting surface 51 by the fixing members 53A and 54. Eight fixing members 53A are arranged at cross positions centered on the central portion CPA of the first surface 52A. More specifically, the fixing members 53A are arranged at equal intervals along the sides 42A and 43A, and are also arranged at equal intervals along the sides 44A and 46A. Five fixing members 54 are arranged at equal intervals on the side 44A, which is the joint with the sensor panel 41B. The size of the fixing area by the fixing members 53A and 54 is the same. In addition, both of the fixing members 53A and 54 are square-shaped. In other words, the fixing area by the fixing members 53A and 54 is a regular polygon shape. The fixing members 53A and 54 are, for example, double-sided tape attached to the mounting surface 51, or adhesive applied or mask-printed on the mounting surface 51. As described in paragraph

[0043] , "equally spaced" refers to "equally spaced" in the sense of including, in addition to completely "equally spaced", an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and does not violate the spirit of the technology of the present disclosure (for example, an error of about 1% to 10%). Furthermore, the "same" in "same size" refers to "same" in the sense of including, in addition to completely "same", an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and does not violate the spirit of the technology of the present disclosure (for example, an error of about 1% to 10%). Furthermore, "regular polygon shape" refers to "regular polygon shape" in the sense of including, in addition to completely "regular polygon shape", an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and does not violate the spirit of the technology of the present disclosure (for example, an error of about 1% to 10%).

[0052] Contact members 56A, 57A, and 58A are in contact with a second surface 55A of the sensor panel 41A opposite to the first surface 52A. The contact members 56A to 58A are in the shape of a long, thin rectangular column. The contact members 56A to 58A are elastic bodies made of various rubbers such as silicone rubber, nitrile rubber (NBR), and urethane rubber, various elastomers, and further various soft resins such as nylon and polyvinyl chloride, or various foams such as polyethylene foam, acrylic foam, and urethane foam.

[0053] The contact members 56A to 58A suppress the lifting of the sensor panel 41A from the support base 50. More specifically, the contact member 56A has approximately the same length as the side 42A, and by contacting the end of the sensor panel 41A on the side 42A side, suppresses the lifting of the end of the sensor panel 41A on the side 42A side from the support base 50. The contact member 57A has approximately the same length as the side 43A, and by contacting the end of the sensor panel 41A on the side 43A side, suppresses the lifting of the end of the sensor panel 41A on the side 43A side from the support base 50. The contact member 58A has a length slightly shorter than the side 46A, and by contacting the end of the sensor panel 41A on the side 46A side, suppresses the lifting of the end of the sensor panel 41A on the side 46A side from the support base 50.

[0054] A surface 59A (hereinafter referred to as contact surface 59A) of the contact member 56A that contacts the second surface 55A has an arcuate shape following the arcuate shape of the side 42A. Similarly, a surface 60A (hereinafter referred to as contact surface 60A) of the contact member 57A that contacts the second surface 55A also has an arcuate shape following the arcuate shape of the side 43A. More specifically, the contact members 56A and 57A as a whole have a shape following the arcuate shape of the sides 42A and 43A. On the other hand, a surface 61A (hereinafter referred to as contact surface 61A) of the contact member 58A that contacts the second surface 55A, and thus the contact member 58A, have a straight shape following the straight shape of the side 46A.

[0055] A retaining member 65A is attached to a surface 62A of the contact member 56A opposite the contact surface 59A. Similarly, a retaining member 66A is attached to a surface 63A of the contact member 57A opposite the contact surface 60A. Furthermore, a retaining member 67A is attached to a surface 64A of the contact member 58A opposite the contact surface 61A.

[0056] The holding members 65A-67A hold the contact members 56A-58A in a state where they are pressed against the sensor panel 41A. The holding members 65A-67A are formed of a material having higher rigidity than the contact members 56A-58A, for example, a metal such as aluminum or copper. Since the contact members 56A-58A are elastic as described above, the holding members 65A-67A hold the contact members 56A-58A in a state where they are pressed against the sensor panel 41A, thereby urging the sensor panel 41A toward the mounting surface 51.

[0057] The holding member 65A has a main body 68A and three mounting pieces 71A. Similarly, the holding member 66A has a main body 69A and three mounting pieces 72A. Furthermore, the holding member 67A has a main body 70A and three mounting pieces 73A. The main bodies 68A and 69A have a shape that follows an arc as a whole, similar to the contact members 56A and 57A. On the other hand, the main body 70A has a straight shape as a whole, similar to the contact member 58A.

[0058] The mounting piece 71A is a portion that protrudes from both ends and the center of the main body 68A at a right angle to the opposite side of the contact member 56A. The mounting piece 72A is a portion that protrudes from both ends and the center of the main body 69A at a right angle to the opposite side of the contact member 57A. The mounting piece 73A is a portion that protrudes from both ends and the center of the main body 70A at a right angle to the opposite side of the contact member 58A. A screw insertion hole 74A is formed in the mounting piece 71A. A screw insertion hole 75A is formed in the mounting piece 72A. A screw insertion hole 76A is formed in the mounting piece 73A. A screw 77A is inserted into the screw insertion hole 74A. A screw 78A is inserted into the screw insertion hole 75A. A screw (not shown) is inserted into the screw insertion hole 76A.

[0059] The screw 77A inserted through the screw insertion hole 74A is screwed into a screw hole 81A of a mounting frame 79A provided on the support base 50. This causes the holding member 65A to be fastened and fixed to the mounting frame 79A. The contact member 56A is held in a state where it is sandwiched between the holding member 65A and the second surface 55A. The screw 78A inserted through the screw insertion hole 75A is screwed into a screw hole 82A of a mounting frame 80A provided on the support base 50. This causes the holding member 66A to be fastened and fixed to the mounting frame 80A. The contact member 57A is held in a state where it is sandwiched between the holding member 66A and the second surface 55A. In addition, the screw inserted through the screw insertion hole 76A is screwed into a screw hole (not shown) of a mounting frame (not shown) provided on the support base 50. This causes the holding member 67A to be fastened and fixed to the mounting frame. The contact member 58A is held in a sandwiched state between the holding member 67A and the second surface 55A.

[0060] A radiation shielding member 83A is attached to the surface of the main body 68A on the side irradiated with radiation R. A radiation shielding member 84A is also attached to the surface of the main body 70A on the side irradiated with radiation R. The radiation shielding members 83A and 84A are made of a material that shields radiation R, such as lead. The radiation shielding member 83A prevents the readout circuit board 45A from being irradiated with radiation R, and protects the readout circuit board 45A. The radiation shielding member 84A prevents the switching circuit board 47A from being irradiated with radiation R, and protects the switching circuit board 47A. In FIG. 9, the contact members 57A and 58A, the holding members 66A and 67A, etc. are not shown to avoid complication.

[0061] 9, the sensor panel 41A has a base material 90A and a scintillator 91A. The scintillator 91A contains, for example, terbium-activated gadolinium oxysulfide (GOS; Gd2O2S:Tb) and converts radiation R into visible light. The scintillator 91A is attached to a support 93A via an adhesive layer 92A. The support 93A is, for example, white PET (Polyethylene Terephthalate). The back surface of the base material 90A is the first surface 52A, and the front surface of the support 93A is the second surface 55A.

[0062] The substrate 90A is a flexible thin film sheet made of resin such as polyimide. The substrate 90A contains inorganic oxide particles that absorb backscattered radiation. Examples of inorganic oxides include silicon dioxide (SiO2), magnesium oxide (MgO), aluminum oxide (also known as alumina, Al2O3), and titanium oxide (TiO2). An example of the substrate 90A having such characteristics is a product named XENOMAX (registered trademark) manufactured by Xenomax Japan Co., Ltd. The thickness TH of the substrate 90A is 100 μm or less. The thickness TH is more preferably 20 μm or more and less than 50 μm (20≦TH<50).

[0063] The base material 90A is provided with pixels 94A that detect visible light converted from radiation R by the scintillator 91A. As is well known, the pixels 94A include a light receiving section that generates charges in response to visible light, and a TFT as a switching element for reading out the charges accumulated in the light receiving section. The base material 90A is provided with a plurality of signal lines for reading out the charges of the light receiving section and inputting them to the circuit board 45A, and a plurality of scanning lines for providing on / off signals (scanning signals) from the switching circuit board 47A to the TFTs, which are arranged to intersect vertically and horizontally. The pixels 94A are arranged at the intersections of the plurality of signal lines and the scanning lines. That is, the pixels 94A are arranged two-dimensionally. The pixels 94A may generate charges not in response to visible light converted from radiation R, but in response directly to radiation R.

[0064] The pitch of the pixels 94A is, for example, 150 μm. The fixing area by the fixing members 53A and 54 has a size that prevents a deviation of more than the pitch of the pixels 94A from occurring between the sensor panel 41A and the support base 50 due to thermal expansion or thermal contraction of the sensor panel 41A. The fixing positions by the fixing members 53A and 54 have an interval that prevents a deviation of more than the pitch of the pixels 94A from occurring between the sensor panel 41A and the support base 50 due to thermal expansion or thermal contraction of the sensor panel 41A.

[0065] As shown in FIG. 10 with the holding members 65A-67A and the like removed, the second surface 55A of the sensor panel 41A has a square imaging area 100A in which the pixels 94A are arranged, and a rectangular annular non-imaging area 101A surrounding the imaging area 100A where the pixels 94A are not arranged. All of the contact members 56A-58A contact the non-imaging area 101A. Similarly, the second surface 55B of the sensor panel 41B has an imaging area 100B and a non-imaging area 101B. All of the contact members 56B, 57B, and 58B that suppress the sensor panel 41B from floating up from the support base 50 contact the non-imaging area 101B.

[0066] The contact member 56B has approximately the same length as the side 42B, and by contacting the end of the sensor panel 41B on the side 42B side, prevents the end of the sensor panel 41B on the side 42B side from lifting up from the support base 50. The contact member 57B has approximately the same length as the side 43B, and by contacting the end of the sensor panel 41B on the side 43B side, prevents the end of the sensor panel 41B on the side 43B side from lifting up from the support base 50. The contact member 58B has a length slightly shorter than the side 46B, and by contacting the end of the sensor panel 41B on the side 46B side, prevents the end of the sensor panel 41B on the side 46B side from lifting up from the support base 50.

[0067] The biasing force of the contact member 56A is greater than that of the contact member 57A. Also, the biasing force of the contact member 57B is greater than that of the contact member 56B. The contact members 56A and 57B are an example of the "first contact member" according to the technology of the present disclosure. Also, the contact members 57A and 56B are an example of the "second contact member" according to the technology of the present disclosure.

[0068] As a method of increasing the biasing force, for example, a method of making the pressing amount of the contact members 56A and 57B larger than the pressing amount of the contact members 57A and 56B can be adopted. For example, when pressing the contact members 57A and 56B of 10 mm to 8 mm, the contact members 56A and 57B are pressed from 10 mm to 6 mm. Alternatively, a method of making the elastic force of the contact members 56A and 57B higher than the elastic force of the contact members 57A and 56B may be used. Note that the reference numeral 53B indicates a fixing member disposed at the cross position centered on the central portion CPB of the first surface of the sensor panel 41B.

[0069] As shown in FIG. 11 as an example, as indicated by the broken line, the sensor panel 41A thermally expands and contracts in the direction parallel to the mounting surface 51 (hereinafter referred to as the surface direction) PD due to the heat during driving. The contact member 56A deforms (shear deformation) as indicated by the broken line in response to the thermal expansion and contraction of the sensor panel 41A.

[0070] The second length L_PD of the contact member 56A along the surface direction PD is shorter than the first length L_ND along the normal direction ND of the mounting surface 51 (L_PD < L_ND). Although the contact member 56A has been described with reference to FIG. 11, the contact members 57A, 58A, 56B to 58B also deform in response to the thermal expansion and contraction of the sensor panels 41A and 41B. Also, for the contact members 57A, 58A, 56B to 58B, the second length L_PD along the surface direction PD is shorter than the first length L_ND along the normal direction ND of the mounting surface 51.

[0071] 12, as an example, an elevation mechanism 110 for vertically raising and lowering the connection member 17, and therefore the frame 18, is a ball screw mechanism composed of the aforementioned screw shaft 22, a nut 111 with a ball that screws onto the screw shaft 22, and an elevation motor 112 that rotates the screw shaft 22. The elevation motor 112 is attached to the rear surface of the stage 13. The height position of the frame 18 is calculated from the rotation direction and the number of rotations of the elevation motor 112.

[0072] The connecting member 17 has a first connecting portion 113 connected to the frame 18, and a second connecting portion 114 connected to the support pillar 14. The first connecting portion 113 protrudes toward the frame 18, and the second connecting portion 114 protrudes toward the support pillar 14, so that the connecting member 17 is generally Z-shaped. A bearing 115 is built into the first connecting portion 113. The bearing 115 is fitted into a guide groove 116 (see also FIG. 1, etc.) formed around the entire circumference of the frame 18. The bearing 115 rolls as the frame 18 rotates. A nut 111 is built into the second connecting portion 114.

[0073] As an example, as shown in FIG. 13, a rotation mechanism 120 for rotating the frame 18 around the subject S is composed of a rotation belt 121 wound around the entire circumference of the frame 18, a rotation motor 122, a potentiometer 123, and the like. The rotation motor 122 is built in the connection member 17B, and is connected to a part of the rotation belt 121 drawn out from the frame 18 via a pulley 124. Drive of the rotation motor 122 causes the frame 18 to rotate in a clockwise (right-handed) direction CW and a counterclockwise (left-handed) direction CCW. The potentiometer 123 is built in the connection member 17C, and is connected to a part of the rotation belt 121 drawn out from the frame 18 via a pulley 125. The potentiometer 123 has a variable resistor whose resistance value changes depending on the rotation position of the frame 18, and outputs a voltage signal according to the rotation position of the frame 18. The rotation position of the frame 18 is determined by the voltage signal from the potentiometer 123.

[0074] As an example, as shown in FIG. 14, a computer constituting the control device 12 includes a storage 130, a memory 131, a CPU (Central Processing Unit) 132, a display 133, an input device 134, and the like.

[0075] The storage 130 is a hard disk drive built into the computer constituting the control device 12 or connected via a cable or network. Alternatively, the storage 130 is a disk array in which multiple hard disk drives are connected in series. The storage 130 stores control programs such as an operating system, various application programs, and various data associated with these programs. Note that a solid state drive may be used instead of a hard disk drive.

[0076] The memory 131 is a work memory for the CPU 132 to execute processing. The CPU 132 loads a program stored in the storage 130 into the memory 131 and executes processing according to the program. In this way, the CPU 132 comprehensively controls each part of the computer. The memory 131 may be built into the CPU 132.

[0077] The display 133 displays various screens. Each screen is provided with an operation function using a GUI (Graphical User Interface). The computer constituting the control device 12 accepts input of operation instructions from the input device 134 via each screen. The input device 134 is a keyboard, a mouse, a touch panel, a microphone for voice input, etc.

[0078] The storage 130 stores an operating program 140. The operating program 140 is an application program for causing a computer to function as the control device 12. In addition to the operating program 140, the storage 130 stores an irradiation condition table 141, order-specific irradiation condition information 142, and the like.

[0079] When the operating program 140 is started, the CPU 132 of the control device 12, in cooperation with the memory 131, etc., functions as a reception unit 145, a read / write (hereinafter abbreviated as RW (Read Write)) control unit 146, a shooting control unit 147, an image processing unit 148, and a display control unit 149.

[0080] The reception unit 145 receives various operation instructions input by an operator via the touch panel display 25 of the apparatus body 11 and the input device 134. For example, the reception unit 145 receives a shooting menu 155. The reception unit 145 outputs the shooting menu 155 to the RW control unit 146.

[0081] The RW control unit 146 receives the imaging menu 155 from the reception unit 145. The RW control unit 146 reads out irradiation conditions 156 of radiation R corresponding to the received imaging menu 155 from the irradiation condition table 141. The RW control unit 146 writes the irradiation conditions 156 read out from the irradiation condition table 141 into the order-specific irradiation condition information 142.

[0082] The imaging control unit 147 controls the operations of the radiation source 20 (radiation tube 35, irradiation field lamp 36, and irradiation field limiter 37), the lifting mechanism 110 (lifting motor 112), the rotation mechanism 120 (rotation motor 122 and potentiometer 123), and the radiation detector 21. The imaging control unit 147 reads out the irradiation conditions 156 from the order-specific irradiation condition information 142. The imaging control unit 147 drives the irradiation field limiter 37 in accordance with the irradiation conditions 156 to adjust the irradiation field. The imaging control unit 147 also drives the radiation tube 35 in accordance with the irradiation conditions 156 to cause the radiation tube 35 to emit radiation R. The imaging control unit 147 causes the radiation detector 21 to output a radiation image (hereinafter referred to as a projection image) detected by the radiation detector 21 as a result of irradiation with radiation R from the radiation detector 21 to an image processing unit 148.

[0083] The image processing unit 148 acquires a projection image from the radiation detector 21. The image processing unit 148 performs various image processing on the projection image. The image processing unit 148 also performs reconstruction processing on a plurality of projection images after image processing to generate a tomographic image TI. The image processing unit 148 outputs the projection image or the tomographic image TI after image processing to the display control unit 149. The image processing unit 148 may also perform processing to correct positional deviation of the pixels 94 due to thermal expansion and thermal contraction of the sensor panel 41.

[0084] The display control unit 149 controls the display of various information on the touch panel display 25 and the display 133. The display control unit 149 receives the projection image or tomographic image TI from the image processing unit 148. The display control unit 149 displays the projection image or tomographic image TI on the touch panel display 25 and the display 133.

[0085] The imaging menu 155 includes, for example, an imaging order ID (Identification Data) and an imaging technique (see FIG. 15). The imaging order ID is identification information of an imaging order issued by a doctor who performs a medical examination using the tomographic image TI. The imaging technique is composed of the posture of the subject S (standing or sitting), the imaging region such as the head, neck, spine, etc., and the attributes of the subject S such as an adult male or adult female.

[0086] The imaging order is transmitted from a radiology information system (RIS) (not shown) to the control device 12. The control device 12 displays a list of imaging orders on the display 133 under the control of the display control unit 149. The operator views the list of imaging orders and confirms the contents. Next, the control device 12 displays an imaging menu 155 corresponding to the imaging order on the display 133 in a settable form. The operator operates the input device 134 to select and input the imaging menu 155 corresponding to the imaging order.

[0087] 15 as an example, the irradiation condition table 141 has irradiation conditions 156 registered for each imaging technique. The irradiation conditions 156 include the tube voltage and tube current applied to the radiation tube 35, and the irradiation time of the radiation R. Although not shown in the figure, the irradiation conditions 156 also include the size of the irradiation field. The irradiation conditions 156 can be finely adjusted by an operator. Note that, instead of the tube current and the irradiation time, the product of the tube current and irradiation time, a so-called mAs value, may be used as the irradiation condition 156.

[0088] Although not shown in the figure, the irradiation condition table 141 also registers a scout imaging position and a main imaging start position for each imaging technique. The scout imaging position is a set of a height position and a rotation position of the frame 18 in the scout imaging. The height position indicates the height of the frame 18 when the surface of the stage 13 is set to 0 cm. The rotation position is, for example, a position where the radiation source 20 directly faces the subject S, that is, a position of 0°. Alternatively, the rotation position may be a 90° position where the radiation source 20 faces the right side of the subject S, or a 270° position where the radiation source 20 faces the left side of the subject S.

[0089] Here, the scout radiography is a preparatory radiography performed to check the positioning of the subject S prior to the actual radiography in which a plurality of projection images are captured at predetermined angles to generate a tomographic image TI. In the scout radiography, the frame 18 is set to a height position and rotation position registered in the irradiation condition table 141, and a lower dose of radiation R is irradiated than in the actual radiography to obtain one projection image. Hereinafter, the projection image obtained by the scout radiography is referred to as a scout image SI (see FIG. 16).

[0090] The main photography start position is the rotation start position of the frame 18 in the main photography. The main photography start position is, for example, a position of 0°. Alternatively, the main photography start position may be a position of 90°.

[0091] Although not shown in the figure, the irradiation conditions 156, the scout photographing position, and the start position of the actual photographing are registered for each photographing order ID in the order-specific irradiation condition information 142. The photographing control unit 147 reads out the irradiation conditions 156, the scout photographing position, and the start position of the actual photographing corresponding to the photographing order ID of the next photographing from the order-specific irradiation condition information 142, and controls the operation of each unit according to the read out irradiation conditions 156, the scout photographing position, and the start position of the actual photographing.

[0092] When guiding the subject S into the apparatus body 11, the frame 18 is moved to a retracted height position by the lifting mechanism 110 under the control of the imaging control unit 147, and is rotated to a 60° position by the rotation mechanism 120. The retracted height position is set on the upper end side of the support 14. More specifically, the retracted height position is the highest point of the lifting range of the frame 18. In this example, the highest point of the lifting range of the frame 18 is approximately the upper end of the support 14, where the second connection part 114 of the connection member 17 abuts against the rear surface of the top plate 15. The 60° position is a position where the entirety of the radiation source 20 overlaps with the support 14A. The operator guides the subject S into the apparatus body 11 in this state, using the space between the support 14A and 14C as an entrance, and positions the subject S.

[0093] After positioning the subject S inside the device body 11, the operator remains at the installation location of the device body 11 and operates the touch panel display 25 to move the frame 18 to the height position registered in the irradiation condition table 141 and rotate the frame 18 to the 0° position. Then, in order to check the irradiation field of the radiation R, the operator operates the touch panel display 25 to turn on the irradiation field lamp 36 and irradiate the irradiation field with visible light.

[0094] The operator visually checks the visible light from the irradiation field lamp 36 and judges whether the height position of the frame 18 and the positioning of the subject S are appropriate for imaging. If the operator judges that the height position of the frame 18 and the positioning of the subject S are not appropriate for imaging, the operator operates the touch panel display 25 to adjust the height position of the frame 18 or reposition the subject S. If the operator judges that the height position of the frame 18 and the positioning of the subject S are appropriate for imaging, the operator operates the touch panel display 25 to turn off the irradiation field lamp 36.

[0095] 16 as an example, after checking the irradiation field of radiation R, the operator moves to the installation location of the control device 12 and operates the input device 134 to input a scout imaging instruction 160 for performing scout imaging. The reception unit 145 receives the scout imaging instruction 160 and outputs that to the imaging control unit 147. The imaging control unit 147 outputs a scout imaging command 161 corresponding to the scout imaging instruction 160 to the radiation source 20, the radiation detector 21, and the rotation mechanism 120.

[0096] The scout radiography command 161 has a content to rotate the frame 18 to the rotation position of the scout radiography position registered in the irradiation condition table 141, while keeping the height position at the time of confirmation of the irradiation field of radiation R. The scout radiography command 161 also has a content to perform scout radiography at the height position at the time of confirmation of the irradiation field of radiation R and at the rotation position of the scout radiography position registered in the irradiation condition table 141. The rotation mechanism 120 rotates the frame 18 to the rotation position of the scout radiography position registered in the irradiation condition table 141 by driving the rotation motor 122 to rotate the rotation belt 121.

[0097] The radiation source 20 drives the radiation tube 35 to irradiate the subject S with radiation R for scout imaging. The radiation detector 21 detects the radiation R that has passed through the subject S to obtain a projection image. The radiation detector 21 outputs the projection image to the image processing unit 148.

[0098] The image processing unit 148 performs various image processing on the projection image from the radiation detector 21 to generate a scout image SI. The image processing unit 148 outputs the scout image SI to the display control unit 149. The display control unit 149 displays the scout image SI on the touch panel display 25 and the display 133.

[0099] The operator views the scout image SI on the display 133 and judges whether the height position of the frame 18 and the positioning of the subject S are appropriate for imaging. If the operator judges from the scout image SI that the height position of the frame 18 and the positioning of the subject S are not appropriate for imaging, the operator returns to the installation location of the device main body 11, turns on the irradiation field lamp 36 again, and adjusts the height position of the frame 18 or repositions the subject S.

[0100] 17 as an example, when it is determined from the scout image SI that the height position of the frame 18 and the positioning of the subject S are appropriate for imaging, the operator operates the input device 134 to input a main imaging instruction 170 for performing the main imaging. The reception unit 145 receives the main imaging instruction 170 and outputs the reception instruction 170 to the imaging control unit 147. The imaging control unit 147 outputs a main imaging command 171 according to the main imaging instruction 170 to the radiation source 20, the radiation detector 21, and the rotation mechanism 120.

[0101] The main photography command 171 rotates the frame 18 to the main photography start position while keeping the height position at the end of the scout photography, and then rotates the frame 18 in the counterclockwise direction CCW to the main photography end position. The main photography command 171 also rotates the main photography while the frame 18 is rotated from the main photography start position to the main photography end position. The rotation mechanism 120 drives the rotation motor 122 to rotate the rotation belt 121, thereby first rotating the frame 18 to the main photography start position. After that, the rotation mechanism 120 rotates the frame 18 in the counterclockwise direction CCW to the main photography end position. In this example, the main photography end position is a position rotated 225° counterclockwise CCW from the main photography start position. If the main photography start position is the 0° position, the main photography end position is a 135° position rotated 225° counterclockwise CCW from the 0° position. Furthermore, when the main photography start position is 90°, the main photography end position is a position of 225°, and when the main photography start position is 180°, the main photography end position is a position of 315°.

[0102] The radiation source 20 drives the radiation tube 35 at each predetermined angle to irradiate the subject S with radiation R for main imaging at each predetermined angle in accordance with the irradiation conditions 156. The radiation detector 21 detects the radiation R that has passed through the subject S at each predetermined angle to obtain a plurality of projection images. The radiation detector 21 sequentially outputs the plurality of projection images to the image processing unit 148.

[0103] The image processing unit 148 performs reconstruction processing on a plurality of projection images from the radiation detector 21 to generate a tomographic image TI. The image processing unit 148 outputs the tomographic image TI to the display control unit 149. The display control unit 149 displays the tomographic image TI on the touch panel display 25 and the display 133.

[0104] The operator views the tomographic image TI on the display 133 and determines whether or not it is necessary to re-capture the tomographic image TI. If it is determined that it is necessary to re-capture the tomographic image TI, the operator operates the input device 134 to re-input the main imaging instruction 170.

[0105] When it is determined that re-imaging of the tomographic image TI is not necessary, the operator operates the input device 134 to return the frame 18 to the evacuation height position. Also, the operator rotates the frame 18 in the clockwise direction CW from the imaging end position to return the frame 18 to the 60° position. Thereafter, the operator evacuates the subject S from inside the apparatus body 11.

[0106] Next, the operation of the above configuration will be described with reference to the flowchart shown in Fig. 18 as an example. When the operating program 140 is started, the CPU 132 of the control device 12 functions as a reception unit 145, a RW control unit 146, an imaging control unit 147, an image processing unit 148, and a display control unit 149 as shown in Fig. 14.

[0107] First, the frame 18 is moved to the retract height position and rotated to a 60° position, and then the subject S is guided into the device body 11 by the operator (step ST100). Then, the subject S is positioned by the operator (step ST110).

[0108] After positioning of the subject S, an operator instructs to turn on the irradiation field lamp 36 via the touch panel display 25. This causes the lifting mechanism 110 to operate and move the frame 18 to the height position registered in the irradiation condition table 141. Also, the rotation mechanism 120 is operated to rotate the frame 18 to a position of 0°. Furthermore, the irradiation field limiter 37 is driven to adjust the irradiation field according to the irradiation condition 156, and then the irradiation field lamp 36 is turned on and visible light is irradiated onto the irradiation field (step ST120).

[0109] With reference to the visible light from the irradiation field lamp 36, the operator determines whether the height position of the frame 18 and the positioning of the subject S are appropriate for imaging (step ST130). If the height position of the frame 18 and the positioning of the subject S are not appropriate for imaging (NO in step ST130), the operator adjusts the height position of the frame 18 or repositions the subject S. If the height position of the frame 18 and the positioning of the subject S are appropriate for imaging (YES in step ST130), the operator issues an instruction to turn off the irradiation field lamp 36 via the touch panel display 25, and the irradiation field lamp 36 is turned off (step ST140).

[0110] 16, after checking the irradiation field of radiation R, the operator inputs a scout imaging instruction 160 via the input device 134. The scout imaging instruction 160 is accepted by the acceptance unit 145. In response to this, a scout imaging command 161 is output from the imaging control unit 147 to the radiation source 20 etc.

[0111] In response to the scout imaging command 161, the rotation mechanism 120 is operated to rotate the frame 18 to the rotation position registered in the irradiation condition table 141. Furthermore, the radiation tube 35 irradiates the subject S with radiation R for scout imaging, and the radiation R that has passed through the subject S is detected by the radiation detector 21 to obtain a projection image (step ST150).

[0112] The projection image obtained by the radiation detector 21 is subjected to various image processing in the image processing unit 148 to become a scout image SI. The scout image SI is displayed on the touch panel display 25 and the display 133 under the control of the display control unit 149 (step ST160).

[0113] With reference to the scout image SI, the operator once again determines whether the height position of the frame 18 and the positioning of the subject S are appropriate for imaging (step ST170). If the height position of the frame 18 and the positioning of the subject S are not appropriate for imaging (NO in step ST170), the operator adjusts the height position of the frame 18 or repositions the subject S.

[0114] If the height position of the frame 18 and the positioning of the subject S are appropriate for imaging (YES in step ST170), an operator inputs a main imaging instruction 170 via the input device 134, as shown in Fig. 17. The main imaging instruction 170 is accepted by the acceptance unit 145. As a result, a main imaging command 171 is output from the imaging control unit 147 to the radiation source 20, etc.

[0115] In response to the main radiography command 171, the rotation mechanism 120 is operated to rotate the frame 18 to the start position of the main radiography. After that, the frame 18 is rotated in the counterclockwise direction CCW to the end position of the main radiography. During this time, the radiation tube 35 irradiates the subject S with radiation R for the main radiography at predetermined angles, and the radiation R that has passed through the subject S is detected by the radiation detector 21 at each time, and multiple projection images are obtained (step ST180).

[0116] A plurality of projection images obtained by the radiation detector 21 are subjected to reconstruction processing by the image processing unit 148 to become a tomographic image TI. The tomographic image TI is displayed on the touch panel display 25 and the display 133 under the control of the display control unit 149 (step ST190).

[0117] The operator determines whether or not it is necessary to re-photograph the tomographic image TI (step ST200). If the operator determines that it is necessary to re-photograph the tomographic image TI (YES in step ST200), the operator re-inputs the actual photography instruction 170 via the input device 134, and the process returns to step ST180.

[0118] If the operator determines that it is not necessary to re-photograph the tomographic image TI, the lifting mechanism 110 is operated to return the frame 18 to the retracted height position in response to an instruction from the operator via the input device 134. In addition, the rotation mechanism 120 is operated to return the frame 18 to a position at 60° in the clockwise direction CW from the photographing end position. After the frame 18 has been returned to the retracted height position and the position at 60°, the subject S is retracted from inside the apparatus body 11 by the operator (step ST210). This series of steps ST100 to ST210 is repeated if there is a next photographing order.

[0119] As shown in FIG. 8 etc., the radiation detector 21 includes a support base 50, a sensor panel 41, fixing members 53 and 54, and contact members 56-58. The support base 50 is formed with a mounting surface 51 having an arcuate surface shape. The sensor panel 41 has an imaging region 100 in which a plurality of pixels 94 for detecting radiation R are arranged two-dimensionally. The sensor panel 41 has a first surface 52 attached to the mounting surface 51 in accordance with the arcuate surface shape. The fixing members 53 and 54 partially fix the first surface 52 to the mounting surface 51. The contact members 56-58 come into contact with a second surface 55 of the sensor panel 41 on the opposite side to the first surface 52, and suppress the sensor panel 41 from lifting up from the support base 50.

[0120] When the entire first surface 52 of the sensor panel 41 is fixed to the mounting surface 51, there is a possibility that wrinkles due to thermal expansion and thermal contraction may occur in the sensor panel 41. However, since the first surface 52 is partially fixed to the mounting surface 51 by the fixing members 53 and 54, this possibility is extremely low. Furthermore, due to the presence of the contact members 56 to 58, it is extremely unlikely that the end of the sensor panel 41 will lift off the support base 50 due to the difference in thermal expansion coefficient between the sensor panel 41 and the support base 50. Therefore, it is possible to stably hold the sensor panel 41. It is possible to eliminate the adverse effects of heat, which is a major issue due to the sensor panel 41 having a relatively large area.

[0121] The positional relationship between the sensor panel 41 and the support base 50 is maintained by the fixing members 53 and 54. Therefore, even if the sensor panel 41 undergoes thermal expansion or contraction, the position of the sensor panel 41 does not shift significantly, and the sensor panel 41 can be returned with good reproducibility to the position before the thermal expansion or contraction.

[0122] 9, the contact members 56 to 58 bias the sensor panel 41 toward the attachment surface 51. This further reduces the possibility that the end portion of the sensor panel 41 will lift up from the support base 50.

[0123] 8 and other drawings, the sensor panel 41 is fixed to the mounting surface 51 by the fixing members 53 at least at the center portion CP of the first surface 52. Therefore, the fixing force can be well balanced compared to the case where the sensor panel 41 is fixed at a biased position, for example, at the end portion.

[0124] 8 and other drawings, the fixing positions of the fixing members 53 and 54 are arranged at equal intervals. Therefore, the fixing forces can be well balanced compared to when the fixing positions are arranged at random intervals.

[0125] The size of the fixing areas provided by fixing members 53 and 54 is the same. Therefore, the fixing forces can be well balanced compared to a case where the sizes of the fixing areas provided by a plurality of fixing members are different.

[0126] The fixing area of ​​the fixing members 53 and 54 is a square (regular polygonal shape), which makes it possible to improve the balance of the fixing forces compared to when the fixing area is not a regular polygonal shape such as a rectangle.

[0127] 11, the contact members 56-58 deform in response to the thermal expansion and thermal contraction in the surface direction PD of the sensor panel 41. By thus deforming the contact members 56-58 and allowing the thermal expansion and thermal contraction of the sensor panel 41 in the surface direction PD, it is possible to further reduce the possibility that wrinkles due to thermal expansion and thermal contraction will occur in the sensor panel 41.

[0128] The contact members 56-58 have a second length L_PD along the surface direction PD that is shorter than a first length L_ND along the normal direction ND. Therefore, the contact members 56-58 are more likely to deform in response to thermal expansion and thermal contraction of the sensor panel 41 in the surface direction PD than when the length L_ND is equal to or shorter than the length L_PD.

[0129] 9, the contact members 56 and 57 have contact surfaces 59 and 60 that contact the second surface 55 so as to conform to the shape of an arcuate surface. Therefore, the contact of the contact members 56 and 57 with the second surface 55 is not uneven in some places, and it is possible to prevent unnecessary stress from being applied to the sensor panel 41.

[0130] The holding members 65-67 hold the contact members 56-58, and have higher rigidity than the contact members 56-58. Therefore, the biasing force that biases the sensor panel 41 toward the attachment surface 51 can be stably maintained.

[0131] 10, the contact members 56-58 come into contact with the non-imaging region 101. For this reason, the contact members 56-58 are not reflected in the projected image, and therefore in the tomographic image TI, and deterioration of the image quality of the tomographic image TI can be prevented.

[0132] As shown in Fig. 10, the contact members include contact members 56A and 57B arranged on the sides 42A and 43B to which the readout circuit boards 45A and 45B are attached, and contact members 57A and 56B arranged on the sides 43A and 42B to which the readout circuit boards 45A and 45B are not attached, facing the sides 42A and 43B. The contact members 56A and 57B have a larger biasing force than the contact members 57A and 56B. The end portions on the sides 42A and 43B have a stronger repulsive force due to the attachment of the readout circuit boards 45A and 45B, and are more likely to float up. However, by increasing the biasing force of the contact members 56A and 57B, it is possible to more firmly suppress the end portions on the sides 42A and 43B from floating up.

[0133] Radiation shielding members 83 and 84 are attached to the contact members 56 and 58 to protect the readout circuit board 45 and the switching circuit board 47 by blocking radiation R. This makes it possible to prevent the performance of the readout circuit board 45 and the switching circuit board 47 from being deteriorated by radiation R.

[0134] 9, the base material 90 of the sensor panel 41 has a thickness TH of 100 μm or less. Therefore, compared to a case where the thickness TH is greater than 100 μm, wrinkles due to thermal expansion and thermal contraction are more likely to occur. In addition, the end portion of the sensor panel 41 is more likely to lift off the support base 50. In other words, it is more difficult to stably hold the sensor panel 41. Therefore, the effect of the technology of the present disclosure, that is, the ability to stably hold the sensor panel, can be more effectively exhibited.

[0135] 9, the support base 50 is made of metal, and the base material 90 of the sensor panel 41 is made of resin. Therefore, the difference in thermal expansion coefficient between the sensor panel 41 and the support base 50 is larger, and wrinkles due to thermal expansion and thermal contraction are likely to occur. In addition, the end of the sensor panel 41 is likely to lift off the support base 50. In other words, it is more difficult to stably hold the sensor panel 41. Therefore, the effect of the technology of the present disclosure, that is, the ability to stably hold the sensor panel, can be more effectively exhibited.

[0136] The sensor panel 41 includes two sensor panels 41A and 41B. Therefore, compared to a case where there is only one sensor panel 41, a wider range of the subject S can be photographed at once.

[0137] The CT device 10 includes a radiation detector 21 and a radiation source 20 that irradiates radiation R. Since the sensor panel 41 of the radiation detector 21 is stably held, it is possible to obtain a tomographic image TI with little degradation in image quality.

[0138] A typical conventional CT device described in Patent Document 1 and the like is configured to irradiate a fan-shaped radiation R from a radiation source 175, scan the radiation R in the height direction (body axis direction of the subject S), and detect the radiation while moving a radiation detector 176 composed of a rectangular CMOS solid-state imaging element bent into an arc shape, as shown in FIG. 19. The CMOS solid-state imaging element is a rectangular shape with a short length in the height direction and a small area, so it is easier to hold it stably compared to the sensor panel 41 with a relatively large area. However, it takes a long time to scan the radiation R. In addition, if a plurality of CMOS solid-state imaging elements are arranged as in Patent Document 1 to shorten the imaging time and form a radiation detector with a large area as a whole, there is a concern that the quality of the tomographic image TI may be deteriorated due to the joints between the CMOS solid-state imaging elements.

[0139] In contrast, the CT device 10 uses a relatively large sensor panel 41, as shown in Figs. 6 and 7, in order to eliminate the need for scanning with radiation R and minimize deterioration of the image quality of the tomographic image TI due to seams. The sensor panel 41, which is difficult to hold stably due to its large area, is held stably by devising an attachment method. Therefore, compared to a conventional CT device that scans with radiation R, the imaging time can be shortened. Also, compared to a conventional CT device in which multiple CMOS type solid-state imaging elements are arranged, deterioration of the image quality of the tomographic image TI can be suppressed.

[0140] The CT device 10 includes an annular frame 18 to which a radiation source 20 and a radiation detector 21 are attached, and a rotation mechanism 120. The frame 18 positions a subject S in a cavity 19. The rotation mechanism 120 rotates the frame 18 around the subject S to capture projection images of the subject S at different angles. The sensor panel 41 has an arcuate surface following the annular frame 18.

[0141] 20 by way of example, if the sensor panel 41 is planar, the dose of radiation R will be lower at the edge of the sensor panel 41 than at the center, resulting in a smaller effective field of view sFOV (Scan Field Of View)1, which is the imaging range that can be reconstructed as a tomographic image TI. In contrast, if the sensor panel 41 is arcuate as in this example, the entire sensor panel 41 is irradiated with substantially the same amount of radiation R, so that the effective field of view sFOV2 can be made larger than the effective field of view sFOV1 (sFOV2>sFOV1). For example, sFOV1 is 384 mm, while sFOV2 is 406 mm. Therefore, by making the sensor panel 41 arcuate, a wider range of the subject S can be imaged at once.

[0142] In this example, the radiation imaging device is a CT device 10 that obtains a tomographic image TI of a subject S based on projection images captured at different angles. If the sensor panel 41 is not held stably, a large deviation occurs between the projection images captured at different angles, which may result in significant deterioration in the image quality of the tomographic image TI. However, in this example, the sensor panel 41 is held stably, so that the risk of deterioration in the image quality of the tomographic image TI can be reduced.

[0143] 6, the radiation source 20 irradiates pyramidal radiation R. Therefore, imaging can be completed in a shorter time than when the radiation source irradiates fan-shaped radiation R and scans in the height direction. Note that conical radiation R may be irradiated instead of pyramidal.

[0144] 1 and 5, the subject S is positioned in the cavity 19 in either a standing or sitting position. This meets the needs of a physician who wants to observe soft tissues such as the lungs in a natural state under the influence of gravity, or a joint such as a hip joint under the influence of gravity and a load.

[0145] The fixing position of the sensor panel 41 by the fixing member may be, for example, as shown in Figures 21 to 24. First, in Figure 21, the fixing member 53A is provided only at the position of the center part CPA of the first surface 52A.

[0146] In FIG. 22, in addition to the central portion CPA of the first surface 52A, the fixing members 53A are provided at symmetrical positions around the central portion CPA. More specifically, the fixing members 53A are provided at the four corners of a square SQ1 that is approximately half the size of the sensor panel 41A. The center of the square SQ1 coincides with the center of the sensor panel 41A. In addition, each side of the square SQ1 is parallel to each side 42A to 44A and 46A of the sensor panel 41A. Therefore, the fixing positions by the fixing members 53A are equidistant from the central portion CPA, 45° above to the right, 45° below to the left, 45° above to the left, and 45° below to the right of the central portion CPA. The fixing positions by the fixing members 53A provided at the four corners of the square SQ1 are arranged at equal intervals. In addition, the "symmetrical" in "symmetrical positions" refers to "symmetrical" in the sense of including, in addition to complete "symmetry," an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and that does not go against the spirit of the technology of the present disclosure (for example, an error of about 1% to 10%).

[0147] In FIG. 23, the fixing members 53A are provided at the four corners of a square SQ2 that is approximately 1 / 3 the size of the sensor panel 41A. The center of the square SQ2 coincides with the center of the sensor panel 41A. The square SQ2 is rotated by 45°, and each side of the square SQ2 forms an angle of 45° with each of the sides 42A to 44A and 46A of the sensor panel 41A. Therefore, the fixing positions by the fixing members 53A are equidistant from the center part CPA, and are above, below, to the right, and to the left of the center part CPA. The fixing positions by the fixing members 53A provided at the four corners of the square SQ2 are arranged at equal intervals.

[0148] 24, a plurality of fixing members 53A are arranged at equal intervals in a matrix shape. A rectangular fixing member 180A that is half the size of fixing member 53A is provided on side 46A.

[0149] As shown in Fig. 21, it is sufficient that the sensor panel 41 is fixed to the mounting surface 51 by the fixing members 53 at least at the center portion CP of the first surface 52. Also, as shown in Figs. 21 to 23, the sensor panel 41 may be fixed to the mounting surface 51 by the fixing members 53 at symmetrical positions around the center portion CP of the first surface 52. In this way, the fixing forces can be better balanced compared to a case where the fixing positions by the multiple fixing members are not symmetrical positions around the center portion CP.

[0150] The fixing area by the fixing member does not have to be square. It may be rectangular as exemplified by fixing member 180A in FIG. 24. It may also be an equilateral triangle, a regular hexagon, or the like. Or it may be circular as in fixing member 185 shown in FIG. 25. A circular shape can improve the balance of the fixing force, as in the case of a regular polygon. Note that the "circular shape" refers to a perfect "circular shape" as well as a "circular shape" including an error that is generally acceptable in the technical field to which the technology of the present disclosure belongs and does not go against the spirit of the technology of the present disclosure.

[0151] The curved shape of the mounting surface 51 is not limited to the illustrated circular arc shape. It may be an elliptical arc shape or a bowl shape like a parabolic antenna. Furthermore, the number of sensor panels 41 is not limited to the illustrated two. There may be one sensor panel 41, or three or more sensor panels. Furthermore, the frame 18 is not limited to a circular ring, and may be a polygonal ring.

[0152] The contact members 56-58 may be formed of a low-density foam to transmit the radiation R. For example, the contact members 56-58 may be configured to transmit 90% or more of the radiation R emitted at a tube voltage of about 120 kV. In this way, even if the contact members 56-58 are in contact with the imaging region 100, the possibility that the contact members 56-58 will be reflected in the projected image, and therefore the tomographic image TI, is low.

[0153] Although an example has been given in which the rear surface of the base material 90 serves as the first surface 52, the sensor panel 41 may be attached to the support base 50 so that the rear surface of the base material 90 serves as the second surface 55. In addition, a position adjustment member for adjusting the position of the sensor panel 41 along the normal direction ND may be attached to the rear surface of the base material 90, etc. In this case, the rear surface of the position adjustment member serves as the first surface 52 or the second surface 55.

[0154] Although the CT device 10 has been exemplified as the radiation imaging device, the present invention is not limited to this. It may be a simple radiation imaging device that captures one projection image at a time by changing the angle. It may also be a radiation imaging device that has a frame to which two sets of radiation source 20 and radiation detector 21 are attached, and irradiates radiation R simultaneously from the front and side of subject S to obtain two projection images, thereby investigating the anatomical shape of the hip joint and spine of subject S, and the connection between the spine and the lower limbs.

[0155] The hardware configuration of the computer constituting the control device 12 can be modified in various ways. For example, the control device 12 can be composed of multiple computers separated as hardware in order to improve processing capacity and reliability. For example, the functions of the reception unit 145 and the RW control unit 146 and the functions of the shooting control unit 147, the image processing unit 148, and the display control unit 149 are distributed and assigned to two computers. In this case, the control device 12 is composed of two computers.

[0156] In this way, the hardware configuration of the computer of the control device 12 can be appropriately changed according to the required performance such as processing power, safety, reliability, etc. Furthermore, not only the hardware, but also the application program such as the operating program 140 can be duplicated or distributed and stored in multiple storage devices for the purpose of ensuring safety and reliability.

[0157] In the above embodiment, for example, the following various processors can be used as the hardware structure of the processing unit that executes various processes, such as the reception unit 145, the RW control unit 146, the photography control unit 147, the image processing unit 148, and the display control unit 149. The various processors include the CPU 132, which is a general-purpose processor that executes software (operation program 140) and functions as various processing units, as well as a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), and / or a dedicated electric circuit, which is a processor having a circuit configuration designed specifically for executing specific processes, such as an ASIC (Application Specific Integrated Circuit).

[0158] A single processing unit may be composed of one of these various processors, or may be composed of a combination of two or more processors of the same or different types (e.g., a combination of multiple FPGAs and / or a combination of a CPU and an FPGA). Also, multiple processing units may be composed of a single processor.

[0159] As an example of configuring multiple processing units with one processor, first, there is a form in which one processor is configured with a combination of one or more CPUs and software, as typified by computers such as client and server, and this processor functions as multiple processing units. Second, there is a form in which a processor is used that realizes the functions of the entire system including multiple processing units with one IC (Integrated Circuit) chip, as typified by System On Chip (SoC), etc. In this way, the various processing units are configured using one or more of the above various processors as a hardware structure.

[0160] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0161] The technology of the present disclosure can be appropriately combined with the above-mentioned various embodiments and / or various modified examples. In addition, it is not limited to the above-mentioned embodiments, and various configurations can be adopted without departing from the gist of the present disclosure. Furthermore, the technology of the present disclosure extends to a storage medium that non-temporarily stores a program, in addition to a program.

[0162] The above description and illustrations are detailed descriptions of the parts related to the technology of the present disclosure, and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, function, action, and effect is an example of the configuration, function, action, and effect of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replaced with respect to the description and illustrations shown above, within the scope of the gist of the technology of the present disclosure. In addition, in order to avoid confusion and to facilitate understanding of the parts related to the technology of the present disclosure, the description and illustrations shown above omit explanations of technical common sense that do not require explanation in order to enable the implementation of the technology of the present disclosure.

[0163] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. In addition, in this specification, the same idea as "A and / or B" is also applied when three or more things are expressed by connecting them with "and / or."

[0164] All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, and standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0165] 10 CT device 11. Device body 12 Control device 13 Stages 14, 14A~14C pillar 15 Tabletop 16 Caster 17, 17A to 17C Connection parts 18 Frames 19 Cavity 20, 175 radiation source 21, 176 Radiation detector 22, 22A~22C Screw shaft 23A~23C opening 24 Movable Arm 25 Touch Panel Display 30 Wheelchair 35 Radiation Tube 36 Field Lamp 37 Irradiation field limiter 40 Case 41, 41A, 41B Sensor Panel 42A~44A, 46A, 42B~44B, 46B 45, 45A, 45B Readout circuit board 47, 47A, 47B Switching circuit board 50 Support stand 51 Mounting surface 52, 52A 1st page 53, 53A, 53B, 54, 180A, 185 Fixing member 55, 55A, 55B 2nd side 56~58, 56A~58A, 56B~58B Contact members 59A to 61A Surface of the contact member that contacts the second surface (contact surface) 62A~64A Surface of the contact member opposite to the contact surface 65A~67A Retaining member 68A~70A Main unit 71A~73A Mounting piece 74A~76A Screw insertion holes 77A, 77B Screws 79A, 80A mounting frame 81A, 82A screw holes 83, 84, 83A, 84A Radiation shielding material 90, 90A base material 91A Scintillator 92A Adhesive layer 93A Support 94, 94A pixels 100, 100A, 100B Imaging area 101, 101A, 101B Non-imaging area 110 Lifting mechanism 111 Nut 112 Lifting motor 113 First Connection 114 Second connection part 115 Bearing 116 Guide groove 120 Rotation Mechanism 121 Rotating Belt 122 Rotation motor 123 Potentiometer 124, 125 Pulley 130 Storage 131 Memory 132 CPU 133 Display 134 Input Devices 140 Operating Program 141 Irradiation Condition Table 142 Irradiation condition information by order 145 Reception 146 Read / write control unit (RW control unit) 147 Shooting control section 148 Image Processing Unit 149 Display control section 155 Shooting Menu 156 Irradiation conditions 160 Scout Shooting Instructions 161 Scout Shooting Order 170 shooting instructions 171 Main shooting command C Frame Center A circle centered on the center of the CC frame and aligned with the support CCW Counterclockwise CP, CPA, CPB Center part of the first page CW Clockwise direction F. Radiation focus ND Normal direction of the mounting surface PD Parallel to the mounting surface (surface direction) R Radiation S Subject sFOV1: Effective field of view when the sensor panel is flat sFOV2: Effective field of view when the sensor panel is arc-shaped SI Scout Images SQ1, SQ2 square ST100, ST110, ST120, ST130, ST140, ST150, ST160, ST170, ST180, ST190, ST200, ST210 Step TH Base material thickness TI Tomographic Image θ Radiation angle

Claims

1. A support base having a curved mounting surface; a sensor panel including a thin film transistor and having an imaging area in which pixels for detecting radiation are arranged two-dimensionally, the sensor panel being attached to the attachment surface with a first surface following the curved shape; a fixing member that partially fixes the first surface to the mounting surface; a contact member that contacts a second surface of the sensor panel opposite the first surface; a holding member for holding the contact member, the holding member having a higher rigidity than the contact member; A radiation detector comprising:

2. A support base having a curved mounting surface; a sensor panel including a thin film transistor and having an imaging area in which pixels for detecting radiation are arranged two-dimensionally, the sensor panel being attached to the attachment surface with a first surface following the curved shape; a fixing member that partially fixes the first surface to the mounting surface; a contact member that contacts a second surface of the sensor panel opposite the first surface; Equipped with a circuit board is attached to a first side of the sensor panel; The contact member is biasing the sensor panel toward the mounting surface; a first contact member disposed on the first side and a second contact member disposed on a second side of the sensor panel opposite the first side and to which the circuit board is not attached; The first contact member has a larger biasing force than the second contact member. Radiation detector.

3. A support base having a curved mounting surface; a sensor panel including a thin film transistor and having an imaging area in which pixels for detecting radiation are arranged two-dimensionally, the sensor panel being attached to the attachment surface with a first surface following the curved shape; a fixing member that partially fixes the first surface to the mounting surface; a contact member that contacts a second surface of the sensor panel opposite the first surface; Equipped with A circuit board is attached to the sensor panel, A radiation shielding member is attached to the contact member to shield the radiation and protect the circuit board. Radiation detector.

4. The radiation detector according to claim 1 , wherein the contact member biases the sensor panel toward the mounting surface.

5. The radiation detector according to claim 1 , wherein the sensor panel is fixed to the attachment surface by the fixing member at least at a central portion of the first surface.

6. The radiation detector according to claim 1 , wherein the sensor panel is fixed to the attachment surface by the fixing members at symmetrical positions around a central portion of the first surface.

7. The fixing members include a plurality of fixing members. The radiation detector according to claim 1 , wherein the fixing positions of the plurality of fixing members are arranged at equal intervals.

8. The fixing members include a plurality of fixing members. The radiation detector according to claim 1 , wherein the sizes of the fixed areas formed by the plurality of fixing members are the same.

9. The radiation detector according to claim 1 , wherein a fixed area by the fixing member has a regular polygonal shape or a circular shape.

10. The radiation detector according to claim 1 , wherein the contact member is deformed in response to thermal expansion and thermal contraction of the sensor panel in a direction parallel to the attachment surface.

11. The radiation detector according to claim 1 , wherein the contact member has a second length in a direction parallel to the mounting surface that is shorter than a first length in a normal direction to the mounting surface.

12. The radiation detector according to claim 1 , wherein the contact member has a surface that comes into contact with the second surface and has a shape that follows the curved shape.

13. The radiation detector according to claim 2 , further comprising a holding member for holding the contact member, the holding member having a rigidity higher than that of the contact member.

14. the second surface has the imaging region and a non-imaging region around the imaging region in which the pixels are not arranged, The radiation detector according to claim 1 , wherein the contact member contacts the non-imaging region.

15. a circuit board is attached to a first side of the sensor panel; The contact member is biasing the sensor panel toward the mounting surface; a first contact member disposed on the first side and a second contact member disposed on a second side of the sensor panel opposite the first side and to which the circuit board is not attached; The radiation detector according to claim 3 , wherein the first contact member has a biasing force greater than that of the second contact member.

16. The radiation detector according to claim 1 , wherein the base material of the sensor panel has a thickness of 100 μm or less.

17. The support base is made of metal, The radiation detector according to claim 1 , wherein a base material of the sensor panel is made of resin.

18. The radiation detector according to claim 1 , comprising two or more sensor panels.

19. A radiation detector according to any one of claims 1 to 18; A radiation source that irradiates the radiation; A radiography apparatus comprising:

20. a ring-shaped frame in which the radiation detector and the radiation source are mounted, the frame having a cavity in which a subject is positioned; a rotation mechanism for rotating the frame around the subject to capture radiation images of the subject at different angles; The radiation imaging apparatus according to claim 19, wherein the curved surface is an arcuate surface.

21. 21. The radiation imaging apparatus according to claim 20, which is a computed tomography apparatus for obtaining a tomographic image of the subject based on the radiation images captured at different angles.

22. 22. The radiographic imaging apparatus according to claim 20, wherein the radiation source irradiates the radiation in a cone shape.

23. 23. The radiographic imaging apparatus according to claim 20, wherein the subject is positioned in the cavity in either a standing position or a sitting position.

Images