Radiation imaging apparatus, operation method of radiation imaging apparatus, and operation program of radiation imaging apparatus

Abstract

To provide a radiographic apparatus in which a confirmation image for confirming image conditions of a subject can be generated without taking time while keeping the image quality of an image for diagnosis provided for doctor's diagnosis, and provide a method for actuating the radiographic apparatus and a program for actuating the radiographic apparatus.SOLUTION: A radiation detector comprises two sheets of sensor panels, and has a sensor panel unit where the ends of the two sheets of sensor panels are put together and arranged in the thickness direction. An image processing unit acquires two sheets of projection images from the two sheets of sensor panels. A synthetic unit of the image processing unit executes processing about image quality on the projection images when generating a tomographic image being an image for diagnosis provided in doctor's diagnosis, and does not execute the processing about image quality on the projection images when generating a scout image being a confirmation image for confirming image conditions of a subject.SELECTED DRAWING: Figure 24

Description

[Technical field]

[0001] The technology disclosed herein relates to a radiation imaging apparatus, an operation method for a radiation imaging apparatus, and an operation program for a radiation imaging apparatus. [Background technology]

[0002] There is known a radiographic imaging device that irradiates a subject with radiation from a radiation source and detects the radiation that has passed through the subject with a radiation detector to obtain a radiographic image of the subject. The radiation detector has a built-in imaging sensor. The imaging sensor has pixels. The pixels generate electric charges in response to radiation or visible light converted from the radiation. The electric charges are read out from the pixels and subjected to various signal processing to obtain a radiographic image.

[0003] Patent Document 1 describes a radiation detector used in a computed tomography (CT) device, the radiation detector having an image sensor unit in which a plurality of rectangular plate-shaped image sensors are arranged. FIG. 12 of Patent Document 1 describes an image sensor unit in which the ends of two adjacent image sensors are overlapped in the thickness direction. FIG. 5 and paragraph

[0035] of Patent Document 1 also describe that in an image sensor unit in which the ends of two adjacent image sensors are overlapped in the thickness direction, an end of one image sensor arranged on the radiation entrance side removes a signal of an area reflected in the other image sensor, and then reconstructs a tomographic image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-339688 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a radiography apparatus, a confirmation image may be generated for an operator such as a radiological technologist to check how the subject is captured at the imaging site, in addition to a diagnostic image such as the tomographic image described in Patent Document 1 that is used by a doctor for diagnosis. The confirmation image only needs to be able to check how the subject is captured, so it does not require image quality as high as that of a diagnostic image. If the time required to generate the confirmation image is long, the overall imaging time will be extended accordingly, so it is better to generate the confirmation image as quickly as possible.

[0006] In Patent Document 1, as described above, when reconstructing a tomographic image, which is a diagnostic image, signals in the reflected area are removed. However, if such image quality processing is also performed on the confirmation image, the time required to generate the confirmation image will be delayed.

[0007] One embodiment of the technology disclosed herein provides a radiographic imaging device, an operating method for a radiographic imaging device, and an operating program for a radiographic imaging device that are capable of generating a confirmation image for checking how a subject is captured without wasting time while ensuring the image quality of a diagnostic image provided for a doctor's diagnosis. [Means for solving the problem]

[0008] The radiographic imaging device disclosed herein includes a radiation source which irradiates a subject with radiation, and at least two imaging sensors, a first imaging sensor and a second imaging sensor, which are rectangular plate-shaped imaging sensors having pixels which generate electric charges in response to radiation or visible light converted from radiation, and is equipped with a radiation detector having an imaging sensor unit in which a first end of the first imaging sensor and a second end of the second imaging sensor are arranged so as to be overlapped in the thickness direction, a processor, and a memory connected to or built into the processor, and the processor acquires a radiographic image of the subject from the imaging sensor, and when generating a diagnostic image from the radiographic image to be used for a doctor's diagnosis, performs image quality processing on the radiographic image, and when generating a confirmation image from the radiographic image to check how the subject is captured, does not perform image quality processing on the radiographic image.

[0009] The first imaging sensor has a first imaging area in which pixels are arranged, and the second imaging sensor has a second imaging area in which pixels are arranged, the first imaging sensor being arranged on the radiation incident side in the thickness direction compared to the second imaging sensor, and the second imaging area has a reflection area in which the first end is reflected, at least in an overlap area where the first end and the second end overlap, and it is preferable that the processor removes the signal of the reflection area from the radiation image when generating a diagnostic image, and does not remove the signal of the reflection area from the radiation image when generating a confirmation image.

[0010] It is preferable that the first imaging region and the second imaging region overlap each other in an overlapping region when the image sensor unit is viewed in a plan view in the thickness direction.

[0011] It is preferable that a marker that is reflected by both the first imaging sensor and the second imaging sensor is attached to the radiation detector at a preset position, and the processor detects a positional shift between the first imaging sensor and the second imaging sensor based on the set position and the position where the marker is actually reflected, and identifies the reflection area based on the detected positional shift.

[0012] It is preferable that the radiation angle of radiation applied to the radiation detector is changeable, and the processor identifies a reflection area that changes depending on the radiation angle.

[0013] It is preferable that the configuration is capable of making radiation obliquely incident on the overlap region and that the size of the focal point of the radiation is changeable, and that the processor identifies a reflection region that changes depending on the size of the focal point.

[0014] The distance between the first and second imaging sensors in the thickness direction is preferably 2 mm or less.

[0015] It is preferable that the width of the reflected area is 10 mm or less.

[0016] It is preferable that the length of one side of the image sensor is 300 mm or more.

[0017] The radiation detector preferably includes a support base having a convex mounting surface facing away from the radiation source, the mounting surface following the convex shape to which the imaging sensor unit is attached.

[0018] The convex shape is preferably U-shaped or V-shaped.

[0019] When the convex shape is a U-shape, it is preferable that a tangent line between the first imaging sensor and the second imaging sensor in the overlapping region and a tangent line between the second imaging sensor and the support base in the overlapping region are parallel.

[0020] When the convex shape is U-shaped, it is preferable that the centers of curvature of the at least two image sensors are at the same position.

[0021] The image sensor unit preferably includes a first image sensor and a second image sensor.

[0022] The image sensor is preferably a sensor panel in which pixels, each of which includes a thin film transistor, are arranged two-dimensionally.

[0023] The base material of the sensor panel is preferably made of resin.

[0024] The present invention preferably comprises an annular frame in which a radiation source and a radiation detector are mounted, 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 at different angles, the radiation detector preferably including a support base having a convex mounting surface facing opposite the radiation source, the mounting surface following the convex shape to which an imaging sensor unit is mounted.

[0025] It is preferable that the apparatus be a computed tomography apparatus that generates a tomographic image of a subject as a diagnostic image based on a plurality of radiation images taken at different angles.

[0026] The confirmation image is preferably a scout image obtained by scout imaging performed prior to capturing the tomographic images.

[0027] The confirmation image is preferably a preview image that is generated based on one of a plurality of radiation images captured at different angles and is displayed before the tomographic image is displayed.

[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.

[0030] The operating method of a radiographic imaging device disclosed herein is provided with: a radiation source which irradiates a subject with radiation; and a radiation detector which includes at least two imaging sensors, a first imaging sensor and a second imaging sensor, which are rectangular plate-shaped imaging sensors having pixels which generate electric charges in response to radiation or visible light converted from radiation, and which has an imaging sensor unit in which a first end of the first imaging sensor and a second end of the second imaging sensor are arranged so as to be overlapped in the thickness direction, the operating method including: obtaining a radiographic image of the subject from the imaging sensors; when generating a diagnostic image for use in a doctor's diagnosis from the radiographic image, performing related processing related to image quality on the radiographic image; and when generating a confirmation image for checking how the subject is captured from the radiographic image, not performing processing related to image quality on the radiographic image.

[0031] The operating program for a radiographic imaging device disclosed herein is an operating program for a radiographic imaging device including a radiation source that irradiates a subject with radiation, and a radiation detector including at least two imaging sensors, a first imaging sensor and a second imaging sensor, which are rectangular plate-shaped imaging sensors having pixels that generate electric charges in response to radiation or visible light converted from radiation, and having an imaging sensor unit in which a first end of the first imaging sensor and a second end of the second imaging sensor are arranged so as to be overlapped in the thickness direction, and causes a computer to execute processes including obtaining a radiographic image of the subject from the imaging sensors, performing image quality processing on the radiographic image when generating a diagnostic image for use by a doctor from the radiographic image, and not performing image quality processing on the radiographic image when generating a confirmation image for checking how the subject is captured from the radiographic image. Effect of the Invention

[0032] According to the technology disclosed herein, it is possible to provide a radiographic imaging device, an operating method for a radiographic imaging device, and an operating program for a radiographic imaging device that are capable of generating a confirmation image for checking how the subject is captured without wasting time while ensuring the image quality of diagnostic images used by a doctor for diagnosis. [Brief description of the drawings]

[0033] [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 an exploded perspective view of two sensor panels, a spacer, and a support base. [Figure 9] FIG. 2 is an exploded plan view of two sensor panels, a spacer, and a support base. [Figure 10] 1 is a cross-sectional view showing the vicinity of an overlapping region at the ends of two sensor panels. [Figure 11] 4 is a diagram showing the positional relationship between the focal point of radiation and a sensor panel. FIG. [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] FIG. 13 is a diagram showing an outline of a process when a main photography instruction for carrying out a main photography is input. [Figure 18] FIG. 2 is a block diagram showing a detailed configuration of an image processing unit. [Figure 19] 11A and 11B are diagrams illustrating positional deviation of a sensor panel. [Figure 20] 11 is a diagram showing a reflection area when a sensor panel is disposed without misalignment. FIG. [Figure 21] 11A and 11B are diagrams showing a reflected area when the position of a sensor panel is misaligned. [Figure 22] 13A and 13B are diagrams illustrating the process of a synthesis unit when generating a tomographic image. [Figure 23] FIG. 13 is a diagram showing the process of a synthesis unit when generating a scout image. [Figure 24] 11 is a table summarizing whether or not processing is performed when generating a scout image and when generating a tomographic image. [Diagram 25] 1 is a flowchart showing a procedure for capturing a tomographic image by a CT apparatus. [Figure 26]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 27] 13A and 13B are diagrams illustrating a process performed by a synthesis unit when generating a preview image. [Figure 28] 10 is a flowchart showing a procedure for capturing a tomographic image by the CT apparatus when a preview image is generated. [Figure 29] FIG. 13 is a diagram showing an example of a configuration capable of changing the irradiation angle of radiation with respect to a radiation detector. [Diagram 30] 13 is a diagram showing a reflected area when radiation is obliquely incident on an overlapping area; FIG. [Diagram 31] FIG. 11 is a diagram showing a process of a synthesis unit when generating a tomographic image in the second embodiment. [Diagram 32] FIG. 13 is a diagram showing an example of a configuration capable of changing the size of the focal point of radiation. [Diagram 33] FIG. 13 is a diagram showing a glare area in the case of a relatively small focus. [Diagram 34] FIG. 13 is a diagram showing a glare area in the case of a relatively large focus. [Diagram 35] FIG. 13 is a diagram showing a process of a synthesis unit when generating a tomographic image in the third embodiment. [Diagram 36] FIG. 13 is an exploded plan view of two sensor panels, a spacer, and a support base according to a fourth embodiment. [Figure 37] 13 is a cross-sectional view showing the vicinity of an overlapping region at the ends of two sensor panels according to a fourth embodiment. FIG. [Figure 38] 13 is a diagram showing the positional relationship between the focal point of radiation and a sensor panel in the fourth embodiment. FIG. [Figure 39] 13 is a table summarizing another example of whether or not processing is performed when generating a scout image and when generating a tomographic image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] [First embodiment] 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. Also, the tomographic image TI is an example of a "diagnostic image" according to the technology of the present disclosure.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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 at 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 arc-shaped surface that is convex toward the opposite side to the radiation source 20, following the shape of the frame 18. The arc-shaped surface is an example of a "U-shape" according to the technology of the present disclosure.

[0042] 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.

[0043] 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.

[0044] 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. The touch panel display 25 also displays various information to the operator.

[0045] 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%).

[0046] 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.

[0047] 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.

[0048] 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°.

[0049] 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. A sensor panel unit 41 is housed in the housing 40. The sensor panel unit 41 includes two sensor panels 42A and 42B using thin film transistors (hereinafter, abbreviated as TFTs (Thin Film Transistors)). The sensor panels 42A and 42B are square-shaped with a side length LP of 300 mm or more (LP≧300 mm) (see FIG. 8). Specifically, the sensor panels 42A and 42B are square-shaped with a size of 17 inches (about 432 mm×about 432 mm). The sensor panel 42A has opposing sides 43A and 44A that are bent in an arc shape that follows the shape of the frame 18. Similarly, the sensor panel 42B has opposing sides 43B and 44B that are bent in an arc shape that follows the shape of the frame 18. The sensor panels 42A and 42B are overlapped at sides 45A and 45B (see FIG. 8 for side 45B) that are not bent into an arc. The sensor panel unit 41 is an example of an "imaging sensor unit" according to the technology of the present disclosure. The sensor panel 42A is an example of a "first imaging sensor" according to the technology of the present disclosure, and the sensor panel 42B is an example of a "second imaging sensor" according to the technology of the present disclosure.

[0050] A readout circuit board 46A is attached to side 44A, and a readout circuit board 46B is attached to side 43B. Nothing is attached to side 43A opposite side 44A, and to side 44B opposite side 43B. Sides 44A and 43B, and thus readout circuit boards 46A and 46B, are in the same position when rotated 180° around the center of radiation detector 21 as an axis, and are in a so-called two-fold symmetric relationship.

[0051] A switching circuit board 48A is attached to side 47A opposite side 45A, and a switching circuit board 48B is attached to side 47B opposite side 45B. As with the supports 14A to 14C, the sensor panels 42A and 42B and their associated parts may hereinafter be referred to by only numbers, omitting the "A" and "B."

[0052] As an example, as shown in FIG. 8 and FIG. 9, the sensor panels 42A and 42B are arranged with the ends 50A on the side 45A side and the ends 50B on the side 45B side overlapping each other in the thickness direction with the sides 45A and 45B parallel to each other. The sensor panels 42A and 42B are fixed at the ends 50A and 50B. The sensor panels 42A and 42B are fixed by, for example, a double-sided tape partially attached to the ends 50B, or an adhesive partially applied or mask-printed on the ends 50B. The sensor panels 42A and 42B are arranged in this order as viewed from the radiation source 20. That is, the sensor panel 42A is arranged closer to the incident side of the radiation R than the sensor panel 42B in the thickness direction. The end 50A is an example of a "first end" according to the technology of the present disclosure, and the end 50B is an example of a "second end" according to the technology of the present disclosure.

[0053] The sensor panel unit 41 is attached to a support base 52. The support base 52 is made of a metal such as aluminum or copper (see FIG. 9), and has a mounting surface 53 that is precisely machined to have a convex arcuate shape (U-shape) facing the opposite side of the radiation source 20, following the shape of the frame 18. The sensor panel unit 41 is attached to the mounting surface 53 in a curved state following the arcuate shape. The radius of the mounting surface 53 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 52 opposite to the mounting surface 53. Here, the "U-shape" refers to a shape in which the sensor panels 42A and 42B are entirely curved, including the imaging regions 61A and 61B described later and the overlapping ends 50A and 50B. More specifically, the "U-shape" refers to a shape in which both ends protrude toward one side, and both ends and the center are connected by a curved surface.

[0054] A spacer 55 is disposed between the first surface 54A of the sensor panel 42A and the mounting surface 53 of the support base 52. The spacer 55 is a thin plate having approximately the same size as the sensor panel 42A and an arcuate surface shape following the shape of the mounting surface 53. The spacer 55 has a thickness according to the distance between the sensor panel 42A and the support base 52. In other words, the spacer 55 has a thickness that fills the step in the thickness direction between the sensor panels 42A and 42B that occurs when the sensor panels 42A and 42B are overlapped. The radius of the sensor panel 42A is, for example, 500 mm, and the radius of the sensor panel 42B is, for example, 501 mm. In this case, the step in the thickness direction between the sensor panels 42A and 42B is 1 mm, and the thickness of the spacer 55 is naturally 1 mm.

[0055] The spacer 55 has the entire first surface 56 attached to the mounting surface 53, and a second surface 58 opposite the first surface 56 faces the first surface 54A of the sensor panel 42A. The spacer 55 and the mounting surface 53 are fixed together, for example, by double-sided tape attached to the mounting surface 53, or by adhesive applied or mask-printed on the mounting surface 53. The first surface 54A of the sensor panel 42A and the second surface 58 of the spacer 55 are in contact with each other but are not fixed together.

[0056] The first surface 54B of the sensor panel 42B is fixed to the mounting surface 53. The sensor panel 42B and the mounting surface 53 are fixed to each other by, for example, double-sided tape that is partially affixed to the mounting surface 53, or an adhesive that is partially applied or mask-printed on the mounting surface 53.

[0057] The second surface 60A of the sensor panel 42A opposite to the first surface 54A has a square imaging area 61A in which pixels 74A (see FIG. 9) are arranged, and a rectangular ring-shaped non-imaging area 62A surrounding the imaging area 61A, where the pixels 74A are not arranged. Similarly, the second surface 60B of the sensor panel 42B opposite to the first surface 54B has an imaging area 61B and a non-imaging area 62B. The imaging area 61A is an example of a "first imaging area" according to the technology of the present disclosure, and the imaging area 61B is an example of a "second imaging area" according to the technology of the present disclosure.

[0058] 9, the sensor panel 42A has a substrate 70A and a scintillator 71A. The scintillator 71A contains, for example, terbium-activated gadolinium oxysulfide (GOS; Gd2O2S:Tb) and converts radiation R into visible light. The scintillator 71A is attached to a support 73A via an adhesive layer 72A. The support 73A is, for example, white PET (Polyethylene Terephthalate). The back surface of the substrate 70A is the first surface 54A, and the front surface of the support 73A is the second surface 60A.

[0059] The substrate 70A is a flexible thin film sheet made of resin such as polyimide. The substrate 70A 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 70A with such characteristics is XENOMAX (registered trademark) manufactured by Xenomax Japan Co., Ltd.

[0060] The substrate 70A is provided with pixels 74A that detect visible light converted from radiation R by the scintillator 71A. As is well known, the pixels 74A 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 substrate 70A 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 46A, and a plurality of scanning lines for providing on / off signals (scanning signals) from the switching circuit board 48A to the TFTs, which are arranged to intersect in the vertical and horizontal directions. The pixels 74A are arranged at the intersections of the plurality of signal lines and the scanning lines. That is, the pixels 74A are arranged two-dimensionally. The pitch of the pixels 74A is, for example, 150 μm. The pixels 74A may generate charges not in response to visible light converted from radiation R, but in response directly to radiation R.

[0061] 10, an overlapping region 80 where end 50A of sensor panel 42A and end 50B of sensor panel 42B overlap is a region defined by an end of side 45A of sensor panel 42A and an end of side 45B of sensor panel 42B. Ends 50A and 50B are fixed to each other in this overlapping region 80 by a fixing member 81. As described above, fixing member 81 is a double-sided tape or an adhesive. Although not shown in the figure, sensor panel 42B and support base 52 are also fixed to each other in the overlapping region 80 by a fixing member.

[0062] The overlapping region 80 is located at the center of the sensor panel unit 41. For this reason, the radiation R is incident on the overlapping region 80 at an irradiation angle of 90° (vertical incidence).

[0063] When the sensor panel unit 41 is viewed in a plan view in the thickness direction, the imaging region 61A of the sensor panel 42A and the imaging region 61B of the sensor panel 42B overlap in an overlapping region 80. The overlapping region of the imaging regions 61A and 61B is hereinafter referred to as an overlapping imaging region 82.

[0064] In the imaging area 61B, there is a reflection area 83 in which the end portion 50A of the sensor panel 42A is reflected in the overlapping area 80. In this example, the reflection area 83 is a combined area of ​​the non-imaging area 62A and the overlapping imaging area 82. The width W of the reflection area 83 is 10 mm or less (W≦10 mm).

[0065] An end 50A of the sensor panel 42A and an end 50B of the sensor panel 42B are parallel to each other. More specifically, a tangent line TGA between the sensor panel 42A and the sensor panel 42B in the overlapping region 80 and a tangent line TGB between the sensor panel 42B and the support base 52 are parallel to each other. The tangent line TGA is a point within a fixing region of the fixing member 81 with the sensor panel 42A, and a point where the tangent line TGA intersects with the center line of the overlapping region 80 is defined as a contact point CTA. The tangent line TGB is a point within a fixing region of the fixing member (not shown) that fixes the sensor panel 42B to the support base 52 with the sensor panel 42B, and a point where the tangent line TGB intersects with the center line of the overlapping region 80 is defined as a contact point CTB.

[0066] Two square markers 84 are attached to the rear surface of the housing 40. The two markers 84 are attached at both ends of the sides 43A and 43B and sides 44A and 44B of the overlapping imaging area 82, which are preset positions within the overlapping imaging area 82. Therefore, the markers 84 are reflected on both the sensor panels 42A and 42B. The presence of the two markers 84 makes it possible to detect not only the deviation in the planar direction from the set positions of the sensor panels 42A and 42B, but also the inclination from the set positions of the sensor panels 42A and 42B. The markers 84 may be detachably attached to the housing 40.

[0067] 11, a perpendicular line PLA extending from the focal point F of the radiation R to the second surface 60A of the sensor panel 42A intersects with the center point CPA of the imaging area 61A. Similarly, a perpendicular line PLB extending from the focal point F to the second surface 60B of the sensor panel 42B intersects with the center point CPB of the imaging area 61B. The perpendicular lines PLA and PLB have the same length and make the same angle with respect to the perpendicular line PL extending from the focal point F to the center point of the sensor panel unit 41. Therefore, the centers (centers of curvature) of the arc surfaces of the sensor panels 42A and 42B coincide with each other at the focal point F. That is, the centers of curvature of the sensor panels 42A and 42B are at the same position. The sensor panels 42A and 42B are also approximately mirror symmetric with respect to the perpendicular line PL. In addition, the "same" in "same position" refers not only to the exact same, but also to 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%).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 CPU 132 is an example of a "processor" according to the technology of the present disclosure. The memory 131 may be built into the CPU 132.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] The imaging control unit 147 controls the operations of the radiation source 20 (the radiation tube 35, the irradiation field lamp 36, and the irradiation field limiter 37), the lifting mechanism 110 (the lifting motor 112), the rotation mechanism 120 (the rotation motor 122 and the 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 detected by the irradiation of radiation R from the radiation detector 21 to the image processing unit 148. Hereinafter, the radiation image detected by the radiation detector 21 will be referred to as a projection image PI (see FIG. 18 ).

[0080] The image processing unit 148 acquires the projection image PI from the radiation detector 21. The image processing unit 148 performs various image processing on the projection image PI. The image processing unit 148 also performs reconstruction processing on a plurality of processed projection images PI to generate a tomographic image TI. The image processing unit 148 outputs the processed projection image PI or the tomographic image TI to the display control unit 149. The image processing unit 148 may also perform processing to correct positional deviation of the pixels 74 due to thermal expansion and thermal contraction of the sensor panel 42.

[0081] 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 PI or the tomographic image TI from the image processing unit 148. The display control unit 149 displays the projection image PI or the tomographic image TI on the touch panel display 25 and the display 133.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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 PI 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 PI. Hereinafter, the projection image PI obtained by the scout radiography is referred to as a scout image SI (see FIG. 16). The scout image SI is an example of a "confirmation image" according to the technology of the present disclosure.

[0087] 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°.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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 PI. The radiation detector 21 outputs the projection image PI to the image processing unit 148.

[0095] The image processing unit 148 performs various image processing on the projection image PI 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.

[0096] 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.

[0097] 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.

[0098] 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°.

[0099] 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 PI. The radiation detector 21 sequentially outputs the plurality of projection images PI to the image processing unit 148.

[0100] The image processing unit 148 performs reconstruction processing on the multiple projection images PI 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.

[0101] 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.

[0102] 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.

[0103] As an example, as shown in FIG. 18, the image processing unit 148 has a positional deviation detection unit 180, a synthesis unit 181, and a reconstruction unit 182. The positional deviation detection unit 180 does not operate when generating a scout image SI, but operates only when generating a tomographic image TI. The projection image PIA from the sensor panel 42A and the projection image PIB from the sensor panel 42B are input to the positional deviation detection unit 180 and the synthesis unit 181. Setting position information 183 indicating the setting position of the marker 84 is also input to the positional deviation detection unit 180. Specifically, the setting position information 183 is the position coordinates of the center of the image 190A of the marker 84 in the projection image PIA (see FIG. 19) when the sensor panel 42A is placed without positional deviation. The setting position information 183 is also the position coordinates of the center of the image of the marker 84 in the projection image PIB when the sensor panel 42B is placed without positional deviation.

[0104] As an example, as shown in FIG. 19, the positional deviation detection unit 180 detects a position where the marker 84 is actually reflected in the projection image PIA (hereinafter, referred to as the reflection position). The reflection position is specifically the position coordinate of the center of the image 191A of the marker 84 reflected in the projection image PIA. The positional deviation detection unit 180 detects the positional deviation of the sensor panel 42A for each of the two markers 84 based on the detected reflection position and the set position of the marker 84 indicated by the set position information 183. The positional deviation of the sensor panel 42A is represented by the difference between the positional coordinate of the center of the image 190A of the marker 84 in the projection image PIA and the positional coordinate of the center of the image 191A of the marker 84 reflected in the projection image PIA when the sensor panel 42A is arranged without positional deviation. Although not shown in the figure, the positional deviation detection unit 180 also performs a similar process on the projection image PIB to detect the positional deviation of the sensor panel 42B. The detection of the misalignment between the sensor panels 42A and 42B by the misalignment detection section 180 is an example of the "processing related to image quality" according to the technique of the present disclosure.

[0105] 18, the positional deviation detection unit 180 outputs positional deviation information 184 indicating the positional deviation between the sensor panels 42A and 42B to the synthesis unit 181. When generating a tomographic image TI, the synthesis unit 181 corrects the positional deviation indicated by the positional deviation information 184 and then synthesizes the projection images PIA and PIB to generate a composite projection image CPI. The synthesis unit 181 outputs the composite projection image CPI to the reconstruction unit 182. The reconstruction unit 182 generates a tomographic image TI based on the composite projection image CPI, and outputs the generated tomographic image TI to the display control unit 149. Note that the process of correcting the positional deviation indicated by the positional deviation information 184 is an example of "processing related to image quality" according to the technology of the present disclosure.

[0106] On the other hand, when generating a scout image SI, the positional deviation detection unit 180 does not operate as described above, and therefore the positional deviation information 184 is not input from the positional deviation detection unit 180 to the synthesis unit 181. Therefore, the synthesis unit 181 synthesizes the projection images PIA and PIB without correcting the positional deviation to generate a composite projection image CPI. The synthesis unit 181 outputs this composite projection image CPI to the display control unit 149 as the scout image SI.

[0107] FIG. 20 shows the reflection area 83 when the sensor panels 42A and 42B are arranged without misalignment. On the other hand, FIG. 21 shows the reflection area 83 when the position of the sensor panel 42B is misaligned with respect to the sensor panel 42A. In this manner, the reflection area 83 changes depending on the relative positional relationship between the sensor panels 42A and 42B. When generating the tomographic image TI, the synthesis unit 181 grasps the relative positional relationship between the sensor panels 42A and 42B from the misalignment information 184 and identifies the reflection area 83. The process of identifying the reflection area 83 is an example of the "processing related to image quality" according to the technology of the present disclosure.

[0108] As an example, as shown in Fig. 22, when generating a tomographic image TI, the synthesis unit 181 identifies a reflection area 83 based on the positional deviation information 184, removes the signal of the identified reflection area 83 from the projection image PIB, and synthesizes the projection image PIA with the reflection area 83. The process of removing the signal of the reflection area 83 is an example of "processing related to image quality" according to the technology of the present disclosure. On the other hand, as an example, as shown in Fig. 23, when generating a scout image SI, the synthesis unit 181 synthesizes the projection image PIA with the projection image PIB without removing the signal of the reflection area 83 from the projection image PIB.

[0109] The above can be summarized as shown in Table 195 in Fig. 24. That is, when generating a scout image SI, the detection of the positional deviation of the sensor panels 42A and 42B by the positional deviation detection unit 180, the correction of the positional deviation by the synthesis unit 181, the specification of the reflection area 83 by the synthesis unit 181, and the removal of the signal of the reflection area 83 by the synthesis unit 181 are not performed. On the other hand, when generating a tomographic image TI, the detection of the positional deviation of the sensor panels 42A and 42B by the positional deviation detection unit 180, the correction of the positional deviation by the synthesis unit 181, the specification of the reflection area 83 by the synthesis unit 181, and the removal of the signal of the reflection area 83 by the synthesis unit 181 are all performed.

[0110] Next, the operation of the above configuration will be described with reference to the flowchart shown in Fig. 25 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.

[0111] 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).

[0112] 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).

[0113] 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).

[0114] 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.

[0115] 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 PI (step ST150).

[0116] The projection image PI obtained by the radiation detector 21 is subjected to various image processing in the image processing unit 148 to become a scout image SI. At this time, as shown in Fig. 23, the signal of the reflected area 83 is not removed from the projection image PIB and is synthesized with the projection image PIA in the synthesis unit 181 of the image processing unit 148. The scout image SI thus generated is displayed on the touch panel display 25 and the display 133 under the control of the display control unit 149 (step ST160).

[0117] 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.

[0118] 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.

[0119] The rotation mechanism 120 is operated by the main radiography command 171, and the frame 18 is first rotated to the main radiography start position. After that, the frame 18 is rotated in the counterclockwise direction CCW to the main radiography end position. During this time, the radiation tube 35 irradiates the subject S with radiation R for the main radiography at predetermined angles, and each time, the radiation R that has passed through the subject S is detected by the radiation detector 21, and a plurality of projection images PI are obtained (step ST180).

[0120] The multiple projection images PI obtained by the radiation detector 21 are subjected to reconstruction processing in the image processing unit 148 to generate a tomographic image TI. At this time, as shown in Fig. 22, in the synthesis unit 181 of the image processing unit 148, the signal of the reflection area 83 is removed from the projection image PIB, and the resulting image is synthesized with the projection image PIA. The tomographic image TI thus generated is displayed on the touch panel display 25 and the display 133 under the control of the display control unit 149 (step ST190).

[0121] 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.

[0122] If the operator determines that re-imaging of the tomographic image TI is not necessary (NO in step ST200), 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 imaging end position. After the frame 18 has been returned to the retracted height position and the 60° position, the subject S is retracted from within the apparatus body 11 by the operator (step ST210). This series of steps ST100 to ST210 is repeated if there is a next imaging order.

[0123] As described above, the radiation detector 21 of the CT device 10 includes the sensor panels 42A and 42B, and has a sensor panel unit 41 in which the end 50A of the sensor panel 42A and the end 50B of the sensor panel 42B are arranged so as to overlap each other in the thickness direction. The image processing unit 148 of the CPU 132 of the control device 12 acquires the projection images PIA and PIB of the subject S from the sensor panels 42A and 42B. When generating a tomographic image TI, which is a diagnostic image provided for the doctor's diagnosis, the synthesis unit 181 of the image processing unit 148 performs image quality processing on the projection image PI, and when generating a scout image SI, which is a confirmation image for checking the subject's image condition, does not perform image quality processing on the projection image PI. The time required to generate the scout image SI is shortened by the amount of time not performing image quality processing. Therefore, it is possible to generate the scout image SI without spending a lot of time while ensuring the image quality of the tomographic image TI.

[0124] When generating a scout image SI, the positional deviation detection unit 180 does not operate, and the synthesis unit 181 does not identify the reflection area 83 based on the positional deviation information 184. Furthermore, when generating a scout image SI, the signal of the reflection area 83 of the projection image PIB is not removed. This makes it possible to further shorten the time required to generate the scout image SI.

[0125] When the sensor panel unit 41 is viewed in a plan view in the thickness direction, the imaging region 61A of the sensor panel 42A and the imaging region 61B of the sensor panel 42B overlap with each other in an overlapping region 80. Therefore, the marker 84 can be reflected on both the sensor panels 42A and 42B.

[0126] A marker 84 that is reflected on both the sensor panels 42A and 42B is attached to the radiation detector 21 at a preset position. The synthesis unit 181 detects the positional deviation of the sensor panels 42A and 42B based on the set position and the actual reflected position of the marker 84, and identifies the reflected area 83 based on the detected positional deviation. This makes it possible to identify a more accurate reflected area 83 that takes into account the positional deviation from the set position of the sensor panels 42A and 42B. As a result, it is possible to suppress deterioration in image quality of the tomographic image TI.

[0127] 10, the width W of the reflection region 83 is 10 mm or less. If the width W of the reflection region 83 is greater than 10 mm, there is a risk that an unnatural feeling will be generated in the tomographic image TI due to removal of the signal of the reflection region 83, but this risk can be reduced.

[0128] 8, the length LP of one side of the sensor panel 42 is 300 mm or more. If the width W of the reflection area 83 is 10 mm or less and the length LP of one side of the sensor panel 42 is 300 mm or more, the proportion of the reflection area 83 in the projection image PI becomes relatively small, about 3%. This makes it possible to further reduce the possibility that an unnatural feeling will be generated in the tomographic image TI due to the removal of the signal from the reflection area 83.

[0129] The radiation detector 21 includes a support base 52 having an arc-shaped mounting surface 53 facing the opposite side to the radiation source 20, on which the sensor panel unit 41 is mounted following the arc-shaped mounting surface 53. As an example, as shown by the dashed line in FIG. 26, if the sensor panel unit 41 is flat, the dose of radiation R is lower at the edge of the sensor panel unit 41 than at the center, and as a result, the effective field of view sFOV (Scan Field Of View)1, which is the imaging range that can be reconstructed as a tomographic image TI, becomes smaller. In contrast, if the sensor panel unit 41 is arc-shaped, the entire sensor panel unit 41 is irradiated with approximately 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 unit 41 arc-shaped, a wider range of the subject S can be imaged at once.

[0130] Incidentally, some conventional CT devices achieve sFOV1 by moving the planar sensor panel unit 41 in the planar direction, but this has the disadvantages of requiring a movement mechanism to move the sensor panel unit 41 in the planar direction, making the device larger, and taking a long time to capture images. In this respect, the CT device 10 of this example does not require a movement mechanism, and does not take a long time to capture images.

[0131] 10, the tangent line TGA between the sensor panels 42A and 42B in the overlapping region 80 and the tangent line TGB between the sensor panel 42B and the support base 52 in the overlapping region 80 are parallel. Therefore, the reflected region 83 can be easily identified compared to the case where the tangent lines TGA and TGB are non-parallel.

[0132] 11, the centers of curvature of the sensor panels 42A and 42B are at the same position. This allows the subject S to be reflected in the projection images PIA and PIB in the same way, and the composite projection image CPI, and therefore the scout image SI and tomographic image TI, can be images that give a less unnatural appearance.

[0133] The sensor panel unit 41 is composed of two sensor panels 42A and 42B. Therefore, the overlapping area 80 that causes deterioration in image quality of the tomographic image TI can be reduced to a minimum of one location, and deterioration in image quality of the tomographic image TI can be suppressed. In addition, the reflection area 83 only needs to be specified in one location, and synthesis only needs to be performed once, so that the time required to generate the tomographic image TI can be shortened. Note that the number of sensor panels 42 is not limited to two, and may be three or more. By increasing the number of panels, a wider range of the subject S can be captured at once.

[0134] As shown in Fig. 9, the sensor panel 42 has pixels 74, each including a TFT, arranged two-dimensionally. The sensor panel 42 using the TFT can be made larger in area and have a higher resolution than other imaging sensors, such as a CMOS (Complementary Metal Oxide Semiconductor) type solid-state imaging element. This makes it possible to capture a wider range of the subject S at once, and obtain a high-quality tomographic image TI. The imaging sensor is not limited to the sensor panel 42, and may be a CMOS type solid-state imaging element.

[0135] 9, the base material 70 of the sensor panel 42 is made of resin. This increases the flexibility of the sensor panel 42, allowing it to be attached easily to the arc-shaped attachment surface 53.

[0136] 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 has a cavity 19 in which a subject S is positioned. The rotation mechanism 120 rotates the frame 18 around the subject S to capture projection images of the subject S at different angles. The radiation detector 21 includes a support base 52 having an arc-shaped mounting surface 53 facing the opposite side to the radiation source 20, and a mounting surface 53 on which a sensor panel unit 41 is attached following the arc-shaped surface. As shown in FIG. 26, by forming the sensor panel unit 41 into an arc-shaped surface, a wider range of the subject S can be captured at once.

[0137] In this example, the radiation imaging device is a CT device 10 that generates a tomographic image TI as a diagnostic image based on projection images PI captured at different angles. When generating a tomographic image TI, the CT device 10 rotates the frame 18 and drives the radiation tube 35 at each predetermined angle to irradiate the subject S with radiation R at each predetermined angle, so that the imaging time is relatively long. For this reason, there is a demand to generate a scout image SI more quickly so that the appearance of the subject S in the scout image SI can be quickly confirmed. For this reason, the effect of the technology of the present disclosure, that is, the ability to generate a scout image SI without spending a lot of time, can be more effectively exhibited.

[0138] 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.

[0139] 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.

[0140] Although a scout image SI is illustrated as an example of a confirmation image, the present invention is not limited to this. As an example, as shown in FIG. 27, when generating a preview image PVI instead of or in addition to the scout image SI, the signal of the reflection area 83 of the projection image PIB may be synthesized with the projection image PIA without removing it. Under the control of the display control unit 149, the preview image PVI is displayed on the touch panel display 25 and the display 133 before the display of the tomographic image TI. The preview image PVI is generated based on one of a plurality of projection images PI captured at different angles, such as the projection images PIA and PIB captured at the start position of the actual shooting (strictly speaking, there are two projection images PIA and PIB, but the projection images PIA and PIB are counted as one).

[0141] In this case, as shown in Fig. 28 as an example, after the main shooting in step ST180 is completed, first, a preview image PVI is generated based on the projection images PIA and PIB obtained at the main shooting start position. At this time, as shown in Fig. 27, in the synthesis unit 181 of the image processing unit 148, the signal of the reflection area 83 is not removed from the projection image PIB, but is synthesized with the projection image PIA. The preview image PVI generated in this way is displayed on the touch panel display 25 and the display 133 under the control of the display control unit 149 (step ST300).

[0142] With reference to the preview image PVI, the operator determines whether or not it is necessary to re-capture the tomographic image TI (step ST310). If the operator determines that it is necessary to re-capture the tomographic image TI (YES in step ST310), the operator re-inputs the actual imaging instruction 170 via the input device 134, and the process returns to step ST180.

[0143] If the operator determines that re-imaging of the tomographic image TI is not necessary (NO in step ST310), the multiple projection images PI obtained by the radiation detector 21 are subjected to reconstruction processing in the image processing unit 148 to generate a tomographic image TI. At this time, as shown in Fig. 22, in the synthesis unit 181 of the image processing unit 148, the signal of the reflection area 83 is removed from the projection image PIB, and the projection image PIA is synthesized. The tomographic image TI thus generated is displayed on the touch panel display 25 and the display 133 under the control of the display control unit 149 (step ST190).

[0144] As with the scout image SI, the preview image PVI should be sufficient if it allows confirmation of how the subject S is captured. For this reason, when generating the preview image PVI, it is preferable to shorten the time required for generation without performing any processing related to image quality.

[0145] [Second embodiment] As shown in Fig. 29 as an example, the radiation source 200 of the second embodiment is configured to be able to change the irradiation angle of radiation R with respect to the radiation detector 21. For example, the radiation source 200 rotates by a predetermined angle along the annular frame 18 from a position directly facing the radiation detector 21. When the radiation source 200 is moved to a position rotated by a predetermined angle from the position directly facing the radiation detector 21, radiation R is incident obliquely on the overlap region 80, as shown in Fig. 30 as an example. The width W of the reflected region 83 in this case is wider than that of the reflected region 83 in the first embodiment in which radiation R is incident at an irradiation angle of 90°, because the image of the end portion 50A reflected in the imaging region 61B is elongated. In other words, the reflected region 83 changes depending on the irradiation angle of the radiation R.

[0146] 31 as an example, in the second embodiment, when generating a tomographic image TI, irradiation angle information 205 indicating the irradiation angle of radiation R is input to the synthesis unit 181 in addition to the positional deviation information 184. The synthesis unit 181 identifies the reflection area 83 based on the positional deviation information 184 and the irradiation angle information 205. Then, the synthesis unit 181 removes the signal of the identified reflection area 83 from the projection image PIB and synthesizes it with the projection image PIA.

[0147] In this way, the second embodiment is configured to be able to change the irradiation angle of radiation R with respect to the radiation detector 21. The synthesis unit 181 identifies the reflection area 83 that changes depending on the irradiation angle. This makes it possible to identify a more accurate reflection area 83 that takes into account the irradiation angle of radiation R. As a result, it is possible to suppress deterioration in image quality of the tomographic image TI.

[0148] The radiation source 20 may be translated in the left-right direction. In addition to or instead of the radiation source 20, the radiation detector 21 may be moved.

[0149] [Third embodiment] 32, like the radiation source 200 of the second embodiment, the radiation source 210 of the third embodiment is configured to be able to change the irradiation angle of radiation R with respect to the radiation detector 21 and is also configured to be able to change the focus F of radiation R between a relatively small focus F1 and a relatively large focus F2. Methods for changing the size of the focus F include, for example, preparing radiation tubes 35 with different sizes of focus F, or changing the diameter of the electron beam provided from the cathode to the anode of the radiation tube 35.

[0150] In this case, as shown in Figures 33 and 34 as an example, radiation R is obliquely incident on overlap region 80. The radiation R emitted from one end of focal point F has a slightly different irradiation angle from the radiation R emitted from the other end of focal point F. Due to this subtle difference in the irradiation angle of radiation R, the QL (Quantum Level) value of projection image PIB does not drop suddenly from QLH to QLL near end 50B, but drops gradually. In the third embodiment, the position where this QL value starts to drop from QLH to QLL is identified as one end of reflected region 83.

[0151] Fig. 33 shows the case of a relatively small focus F1, and Fig. 34 shows the case of a relatively large focus F2. The width W of the reflected area 83 in the case of focus F2 is wider than that of the reflected area 83 in the case of focus F1. In other words, the reflected area 83 changes depending on the size of the focus F of the radiation R.

[0152] 35 as an example, in the third embodiment, when generating a tomographic image TI, in addition to the positional deviation information 184 and the irradiation angle information 205, focal spot size information 215 indicating the size of the focal spot F of the radiation R is input to the synthesis unit 181. The synthesis unit 181 identifies the reflection area 83 based on the positional deviation information 184, the irradiation angle information 205, and the focal spot size information 215. Then, the synthesis unit 181 removes the signal of the reflection area 83 from the projection image PIB and synthesizes it with the projection image PIA.

[0153] As described above, the third embodiment is configured to allow radiation R to be obliquely incident on the overlap region 80, and is also configured to allow the size of the focus F of radiation R to be changed. The synthesis unit 181 identifies the reflection region 83 that changes depending on the size of the focus F. This makes it possible to identify a more accurate reflection region 83 that takes into account the size of the focus F of radiation R. As a result, it is possible to suppress deterioration in image quality of the tomographic image TI. Note that the focus F to be changed is not limited to two, the focus F1 and the focus F2, and may be three or more.

[0154] In the second and third embodiments, it is preferable that the distance D between the sensor panels 42A and 42B in the thickness direction is 2 mm or less, as shown in Fig. 30 and Fig. 33. If the distance D is greater than 2 mm, the image of the end portion 50A reflected in the imaging region 61B will be stretched accordingly, widening the width W of the reflected region 83, and there is a risk that an unnatural feeling will be generated in the tomographic image TI due to the removal of the signal from the reflected region 83.

[0155] [Fourth embodiment] In the above first embodiment and the like, the support base 52 having the mounting surface 53 having an arcuate surface (U-shape) has been exemplified, but the present invention is not limited to this.

[0156] As an example, as shown in FIG. 36, the support base 220 of the fourth embodiment has a V-shaped mounting surface 221. Here, the "V-shape" refers to a shape in which most of the sensor panels 42A and 42B, including the imaging regions 61A and 61B, are flat, and the overlapping ends 50A and 50B intersect at an angle of less than 180°. More specifically, the "V-shape" refers to a shape in which both ends protrude toward one side, and both ends and the center are connected by a flat surface. A spacer 222 is attached to the mounting surface 221. The spacer 222 is a thin plate having approximately the same size as the sensor panel 42A and a straight shape that follows the shape of the mounting surface 221. The spacer 222 has a thickness according to the distance between the sensor panel 42A and the support base 220.

[0157] Sensor panels 42A and 42B are fixed at end portions 50A and 50B. Furthermore, sensor panel 42B has a first surface 54B fixed at end portion 50B to mounting surface 221. This gives sensor panel unit 41 a V-shape that matches the shape of mounting surface 221.

[0158] 37, fixing member 230 that fixes end 50A of sensor panel 42A and end 50B of sensor panel 42B has an irregular shape compared to the simple shape of fixing member 81 of the first embodiment, because end 50A and end 50B cross in a V shape. For this reason, fixing member 230 is made of a material that has a higher degree of freedom in shape than fixing member 81.

[0159] 38 as an example, in the fourth embodiment, a perpendicular line PLA extending from the focal point F of the radiation R to the second surface 60A of the sensor panel 42A intersects with the center point CPA of the imaging area 61A. Similarly, a perpendicular line PLB extending from the focal point F to the second surface 60B of the sensor panel 42B intersects with the center point CPB of the imaging area 61B. The perpendicular lines PLA and PLB have the same length and make the same angle with respect to the perpendicular line PL extending from the focal point F to the center point of the sensor panel unit 41. Therefore, the sensor panels 42A and 42B are approximately mirror symmetric with respect to the perpendicular line PL.

[0160] Even when the mounting surface 221 is V-shaped and the sensor panel unit 41 is shaped to match it, the effective field of view sFOV2 can be made larger than the effective field of view sFOV1 when the sensor panel unit 41 is flat. In this case, the base material 70 of the sensor panel 42 may be made of glass instead of resin as in the above example.

[0161] The U-shape is not limited to the illustrated circular arc shape, but may be an elliptical arc shape or a bowl shape like a parabolic antenna. Also, the frame 18 is not limited to a circular ring, but may be a polygonal ring.

[0162] Although an example has been given in which the rear surface of the base material 70 serves as the first surface 54 , the sensor panel 42 may be attached to the support base 52 so that the rear surface of the base material 70 serves as the second surface 60 .

[0163] The "processing related to image quality" is not limited to the processing for removing the signal from the reflected area 83 given as an example above. For example, the processing of table 235 shown in FIG.

[0164] In the example of FIG. 39, offset correction, defective pixel correction, shading correction, residual image correction, scattered radiation correction, and reference correction are shown as processes for generating a scout image SI and a tomographic image TI. Offset correction is a process of subtracting an offset correction image detected in a state where radiation R is not irradiated from the projection image PI in units of pixels 74. Defective pixel correction is a process of linearly interpolating the pixel values ​​of pixels 74 with abnormal pixel values ​​in the projection image PI with the pixel values ​​of surrounding normal pixels 74 based on information on pixels (defective pixels) 74 with abnormal pixel values ​​generated at the time of shipment or during regular inspection. Shading correction is a process of correcting variations in the sensitivity of the light receiving unit of each pixel 74, variations in the output characteristics of the readout circuit, and the like, based on shading correction data. Residual image correction is a process of removing residual images caused by the previous shooting from the projection image PI.

[0165] The scattered radiation correction is a process of removing scattered radiation components from the projection image PI using scattered radiation correction data prepared in advance according to various body types of the subject S, such as thin, normal, and fat. The reference correction is a process of using pixel values ​​of a non-reflecting area in the projection image PI where the subject S is not reflected as a reference. The pixel values ​​of the non-reflecting area indicate fluctuations in the output of the radiation source 20 over time. For example, if the tube current applied to the radiation source 20 becomes higher than a set value due to fluctuations over time, the pixel values ​​of the non-reflecting area become higher than an expected value. The reference correction is a process of multiplying the projection image PI by a correction coefficient corresponding to the difference between the actual pixel values ​​of the non-reflecting area and the expected value. For example, if the pixel values ​​of the non-reflecting area are higher than the expected value, the projection image PI is multiplied by a correction coefficient smaller than 1.

[0166] In the example of FIG. 39, offset correction and defective pixel correction are performed both when generating a scout image SI and when generating a tomographic image TI. In contrast, shading correction, afterimage correction, scattered radiation correction, and reference correction are not performed when generating a scout image SI, but are performed when generating a tomographic image TI. In this case, shading correction, afterimage correction, scattered radiation correction, and reference correction are examples of "processing related to image quality" according to the technology of the present disclosure. Note that when generating a scout image SI, not only shading correction, afterimage correction, scattered radiation correction, and reference correction, but also offset correction and defective pixel correction may not be performed.

[0167] When generating a scout image SI, 4×4 or 3×3 binning is applied to the projection image PI, and when generating a tomographic image TI, 2×2 binning or no binning is applied to the projection image PI, so that the number of pixels handled when generating the scout image SI can be reduced compared to the number of pixels handled when generating the tomographic image TI. This can also shorten the time required to generate the scout image SI.

[0168] Note that, when the sensor panel unit 41 is viewed in a plan view in the thickness direction, the imaging region 61A of the sensor panel 42A and the imaging region 61B of the sensor panel 42B do not have to overlap in the overlapping region 80. What is important is that the imaging region 61B has a reflection region 83 in which the end portion 50A is reflected.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] In each of the above embodiments, the following various processors can be used as the hardware structure of the processing units that execute various processes, such as the reception unit 145, the RW control unit 146, the imaging control unit 147, the image processing unit 148 (position deviation detection unit 180, synthesis unit 181, and reconstruction unit 182), 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), etc.

[0173] 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.

[0174] 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.

[0175] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0176] From the above description, it is possible to grasp the inventions relating to the following image processing device in Supplementary Items 1 to 3. In the above embodiments, the control device 12 is an example of the "image processing device".

[0177] [Additional note 1] A radiation source that irradiates a subject with radiation; a radiation detector having an image sensor unit including at least two image sensors, a first image sensor and a second image sensor, each of which has a rectangular plate shape and has pixels that generate electric charges in response to the radiation or visible light converted from the radiation, and in which a first end of the first image sensor and a second end of the second image sensor are arranged so as to be overlapped in a thickness direction; A radiography apparatus comprising: In an image processing device used in A processor; A memory connected to or embedded in the processor; Equipped with The processor, acquiring a radiation image of the subject from the imaging sensor; When generating a diagnostic image for use in a doctor's diagnosis from the radiation image, image quality processing is performed on the radiation image; When generating a confirmation image for checking the appearance of the subject from the radiation image, the image quality processing is not performed on the radiation image. Image processing device.

[0178] [Additional note 2] A radiation source that irradiates a subject with radiation; a radiation detector having an image sensor unit including at least two image sensors, a first image sensor and a second image sensor, each of which has a rectangular plate shape and has pixels that generate electric charges in response to the radiation or visible light converted from the radiation, and in which a first end of the first image sensor and a second end of the second image sensor are arranged so as to be overlapped in a thickness direction; A radiography apparatus comprising: A method for operating an image processing apparatus for use in acquiring a radiation image of the subject from the imaging sensor; When generating a diagnostic image for use in a doctor's diagnosis from the radiation image, image quality processing is performed on the radiation image; and when generating a confirmation image for checking the appearance of the subject from the radiation image, the processing related to the image quality of the radiation image is not performed; A method of operating an image processing apparatus comprising:

[0179] [Additional note 3] A radiation source that irradiates a subject with radiation; a radiation detector having an image sensor unit including at least two image sensors, a first image sensor and a second image sensor, each of which has a rectangular plate shape and has pixels that generate electric charges in response to the radiation or visible light converted from the radiation, and in which a first end of the first image sensor and a second end of the second image sensor are arranged so as to be overlapped in a thickness direction; A radiography apparatus comprising: In the operating program of the image processing device used in acquiring a radiation image of the subject from the imaging sensor; When generating a diagnostic image for use in a doctor's diagnosis from the radiation image, image quality processing is performed on the radiation image; and when generating a confirmation image for checking the appearance of the subject from the radiation image, the processing related to the image quality of the radiation image is not performed; A method of operating an image processing device that causes a computer to execute a process including the steps of:

[0180] 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 technology. Furthermore, the technology of the present disclosure extends to a storage medium that non-temporarily stores a program, in addition to a program.

[0181] 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.

[0182] 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."

[0183] 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]

[0184] 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, 200, 210 radiation sources 21 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 Sensor panel unit 42, 42A, 42B Sensor Panel 43A~45A, 47A, 43B~45B, 47B 46A, 46B Readout circuit board 48A, 48B Switching circuit board 50A, 50B end 52, 220 support stand 53, 221 Mounting surface 54, 54A, 54B First surface of sensor panel 55, 222 Spacer 56 First surface of spacer 58 Second surface of spacer 60, 60A, 60B Second side of sensor panel 61A, 61B Imaging area 62A, 62B Non-imaging area 70, 70A base material 71A Scintillator 72A Adhesive layer 73A Support 74, 74A pixels 80 Overlapping area 81, 230 Fixing member 82 Overlapping imaging area 83 Reflection area 84 Marker 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 180 Position deviation detection unit 181 Synthesis Section 182 Reconstruction part 183 Setting location information 184 Position deviation information 190A The image of the marker in the projected image when the sensor panel is placed without misalignment 191A Image of a marker reflected in a projected image 195, 235 table 205 Beam Angle Information 215 Focus size information C Frame Center A circle centered on the center of the CC frame and aligned with the support CCW Counterclockwise CPA, CPB Center point of imaging area CPI synthetic projection image CTA, CTB contact CW Clockwise direction D Sensor Panel Spacing F, F1, F2 Radiation focus LP Sensor panel side length PI, PIA, PIB projection image Perpendicular line drawn from the focus of PL radiation to the center point of the sensor panel unit PLA, PLB Perpendicular line from the focal point of radiation to the second surface of the sensor panel PVI Preview Image QLH, QLL QL value 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 ST100, ST110, ST120, ST130, ST140, ST150, ST160, ST170, ST180, ST190, ST200, ST210, ST300, ST310 Step TGA, TGB tangent TI Tomographic Image W Width of the reflection area θ Radiation angle

Claims

1. A radiation source that irradiates a subject with radiation; a radiation detector having an imaging sensor unit including at least two imaging sensors, a first imaging sensor and a second imaging sensor, each of which is a rectangular plate having pixels that generate electric charges in response to the radiation or visible light converted from the radiation, wherein a first end of the first imaging sensor and a second end of the second imaging sensor are arranged so as to be overlapped in a thickness direction, the first imaging sensor has a first imaging region in which the pixels are arranged and the second imaging sensor has a second imaging region in which the pixels are arranged, the first imaging sensor is disposed on a side closer to the incidence of the radiation than the second imaging sensor in the thickness direction, and the second imaging region has a reflection region in which the first end is reflected, at least in an overlap region in which the first end and the second end overlap; A processor; A memory connected to or embedded in the processor; Equipped with The processor, acquiring a radiation image of the subject from the imaging sensor; When generating a diagnostic image for use in a doctor's diagnosis from the radiation image, the signal of the reflected region is removed from the radiation image; When generating a confirmation image for checking the reflection state of the subject from the radiation image, the signal of the reflection region is not removed from the radiation image. Radiography equipment.

2. The radiation imaging apparatus according to claim 1 , wherein the first imaging region and the second imaging region overlap each other in the overlapping region when the image sensor unit is viewed in a plan view in the thickness direction.

3. a marker that is reflected by both the first image sensor and the second image sensor is attached to the radiation detector at a preset position; The processor, detecting a positional deviation between the first image sensor and the second image sensor based on the set position and an actual position where the marker is captured; The radiographic imaging apparatus according to claim 2 , wherein the reflected region is identified based on the detected positional deviation.

4. an irradiation angle of the radiation with respect to the radiation detector can be changed, The processor, The radiation imaging apparatus according to claim 1 , wherein the reflected region is determined to change depending on the irradiation angle.

5. a configuration capable of making the radiation obliquely incident on the overlapping region and a configuration capable of changing a size of a focal point of the radiation, The processor, The radiation imaging apparatus according to claim 1 , wherein the reflected region is determined to change depending on a size of the focal point.

6. 6. The radiation imaging apparatus according to claim 4, wherein a distance between the first image sensor and the second image sensor in the thickness direction is 2 mm or less.

7. The radiographic imaging apparatus according to claim 1 , wherein the width of the reflected area is 10 mm or less.

8. 8. The radiation imaging apparatus according to claim 7, wherein the length of one side of the image sensor is 300 mm or more.

9. 9. The radiation imaging device according to claim 1, wherein the radiation detector includes a support base having a convex mounting surface facing away from the radiation source, the support base having a mounting surface on which the image sensor unit is mounted following the convex shape.

10. The radiographic imaging apparatus according to claim 9 , wherein the convex shape is a U-shape or a V-shape.

11. The radiation imaging device according to claim 10 , wherein when the convex shape is a U-shape, a tangent between the first imaging sensor and the second imaging sensor in the overlapping region and a tangent between the second imaging sensor and the support table in the overlapping region are parallel to each other.

12. 12. The radiation imaging apparatus according to claim 10, wherein when the convex shape is a U-shape, the centers of curvature of at least two of the image sensors are at the same position.

13. 13. The radiation imaging apparatus according to claim 1, wherein the imaging sensor unit is composed of two imaging sensors, the first imaging sensor and the second imaging sensor.

14. 14. The radiation imaging apparatus according to claim 1, wherein the image sensor is a sensor panel in which the pixels, each including a thin film transistor, are two-dimensionally arranged.

15. 15. The radiation imaging apparatus according to claim 14, wherein a base material of the sensor panel is made of resin.

16. a ring-shaped frame in which the radiation source and the radiation detector are mounted, the frame having a cavity in which the subject is positioned; a rotation mechanism for rotating the frame around the subject in order to capture the radiation images at different angles; 16. The radiation imaging device according to claim 1, wherein the radiation detector includes a support base having an arc-shaped mounting surface facing an opposite side to the radiation source, the mounting surface being adapted to mount an image sensor unit following the arc-shaped mounting surface.

17. 17. The radiation imaging apparatus according to claim 16, which is a computed tomography apparatus that generates a tomographic image of the subject as the diagnostic image based on a plurality of the radiation images captured at different angles.

18. 18. The radiographic imaging apparatus according to claim 17, wherein the confirmation image is a scout image obtained by scout imaging performed prior to capturing the tomographic images.

19. 19. The radiographic imaging apparatus according to claim 17, wherein the confirmation image is a preview image generated based on one of a plurality of the radiographic images taken at different angles and displayed before the tomographic image is displayed.

20. The radiographic imaging apparatus according to claim 16 , wherein the radiation source emits the cone-shaped radiation.

21. 21. The radiographic imaging apparatus according to claim 16, wherein the subject is positioned in the cavity in either a standing position or a sitting position.

22. A radiation source that irradiates a subject with radiation; a radiation detector having an imaging sensor unit including at least two imaging sensors, a first imaging sensor and a second imaging sensor, each of which is a rectangular plate having pixels that generate electric charges in response to the radiation or visible light converted from the radiation, wherein a first end of the first imaging sensor and a second end of the second imaging sensor are arranged so as to be overlapped in a thickness direction, the first imaging sensor has a first imaging region in which the pixels are arranged and the second imaging sensor has a second imaging region in which the pixels are arranged, the first imaging sensor is disposed on a side closer to the incidence of the radiation than the second imaging sensor in the thickness direction, and the second imaging region has a reflection region in which the first end is reflected, at least in an overlap region in which the first end and the second end overlap; A method for operating a radiation imaging apparatus comprising: acquiring a radiation image of the subject from the imaging sensor; When generating a diagnostic image for use in a doctor's diagnosis from the radiation image, a signal of the reflected region is removed from the radiation image; and when generating a confirmation image for checking the reflection state of the subject from the radiation image, the signal of the reflection region is not removed from the radiation image; A method for operating a radiation imaging apparatus comprising:

23. A radiation source that irradiates a subject with radiation; a radiation detector having an imaging sensor unit including at least two imaging sensors, a first imaging sensor and a second imaging sensor, each of which is a rectangular plate having pixels that generate electric charges in response to the radiation or visible light converted from the radiation, wherein a first end of the first imaging sensor and a second end of the second imaging sensor are arranged so as to be overlapped in a thickness direction, the first imaging sensor has a first imaging region in which the pixels are arranged and the second imaging sensor has a second imaging region in which the pixels are arranged, the first imaging sensor is disposed on a side closer to the incidence of the radiation than the second imaging sensor in the thickness direction, and the second imaging region has a reflection region in which the first end is reflected, at least in an overlap region in which the first end and the second end overlap; An operating program for a radiation imaging apparatus comprising: acquiring a radiation image of the subject from the imaging sensor; When generating a diagnostic image for use in a doctor's diagnosis from the radiation image, a signal of the reflected region is removed from the radiation image; and when generating a confirmation image for checking the reflection state of the subject from the radiation image, the signal of the reflection region is not removed from the radiation image; An operating program for a radiation imaging apparatus that causes a computer to execute a process including the steps of:

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