JP2010085265A - Radiation detecting device and radiography system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable compensation of the sensitivity of each pixel to be fixed even when the shape of a flexible radiation detector changes along the shape of the surface of a subject, and thereby to obtain a radiation image of a high grade. <P>SOLUTION: A radiation detecting device includes the flexible radiation detector 30, an incidence angle detecting part 110 which detects an angle of incidence of radiation 12 on each pixel of the radiation detector 30, which accompanies the change in the shape of the detector 30, and a sensitivity compensating part 112 which compensates the sensitivity in each pixel of the detector 30, based on the incidence angle. The incidence angle detecting part 110 has a tilt angle operation part 126 which computes an angle of tilt to a datum plane of each of solid block bodies 32 arranged in the radiation detector 30, based on an output from a pressure sensor 114, and an incidence angle operation part 128 which determines the incidence angle for each pixel, based on a map wherein reference tilt angles for which the direction from each solid block body 32 to a radiation source 16 is a normal direction are arranged and on the tilt angle of each solid block body 32 obtained by the tilt angle operation part 126, and stores it in an incidence angle information table. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radiation detection apparatus including a radiation detector that detects radiation transmitted through a subject and converts the detected radiation into radiation image information, and a radiation imaging system including the radiation detection apparatus.

  In the medical field, radiation imaging systems that irradiate a subject with radiation and guide the radiation transmitted through the subject to a radiation detector to capture radiation image information are widely used. As the radiation detector, a conventional radiation film in which the radiation image information is exposed and recorded, or radiation energy as the radiation image information is accumulated in a phosphor, and the radiation image information is obtained by irradiating excitation light. A stimulable phosphor panel that can be extracted as stimulated emission light is known. These radiation detectors supply the radiation film on which the radiation image information is recorded to a developing device to perform development processing, or supply the storage phosphor panel to a reading device to perform reading processing. A visible image can be obtained.

  On the other hand, in an operating room or the like, it is necessary to be able to immediately read out and display radiation image information from a radiation detector after imaging in order to perform a quick and accurate treatment on a patient. Radiation detection using a solid state detector that converts radiation directly into an electrical signal, or converts radiation into visible light with a scintillator, and then converts it into an electrical signal and reads it out A vessel has been developed.

  In the past, an X-ray diagnostic apparatus has been proposed in which an X-ray solid state detector is made flexible so that the X-ray solid state detector can be matched to an arbitrary surface shape. (For example, refer to Patent Document 1).

  In addition, when a load is applied to the radiation detector, the dark current characteristics and sensitivity characteristics may change, so use these characteristics to install a load sensor on the radiation detector to correct the image quality. A radiation imaging apparatus has been proposed (see, for example, Patent Document 2).

JP 2003-70776 A JP 2002-357664 A

  By the way, when radiography is performed using a radiation detector, the subject is irradiated with radiation while the subject is in contact with the radiation detector. At this time, if the radiation detector is flat and rigid, it will not be deformed even if it comes into contact with the subject, so the orientation of the pixels formed in the radiation detector, that is, the orientation relative to the radiation source does not change. That is, the variation in sensitivity of each pixel is constant regardless of the surface shape of the subject. In addition, since there is a track record of imaging with a flat and rigid radiation detector, the points to be taken into consideration regarding the sensitivity variation of the reproduced radiation image are enhanced. Of course, since the variation in the sensitivity of the reproduced radiographic image is almost constant, the correction method is simple.

  However, when a radiation detector having flexibility is used, the radiation detector is deformed following the surface shape of the subject, and thereby the orientation of the pixels formed inside the radiation detector, that is, with respect to the radiation source. The direction will change. When the orientation of the pixel with respect to the radiation source changes, the amount of radiation incident on the pixel changes, and the sensitivity changes accordingly. That is, the variation in sensitivity of each pixel changes depending on the surface shape of the subject, and there is a possibility that the past results cannot be used in interpreting the reproduced radiation image. In addition, paragraph [0008] of Patent Document 1 states that “an image distortion that exists in the output signal of the X-ray solid-state detector connected to this measuring device and an X-ray solid state detector connected to this measuring device is present. It is advantageous that a correction means for correcting is provided ”, and the details of how to detect the bending of the substrate and what kind of image distortion is provided. Is not described, so it is unclear how to configure.

  The present invention has been made in consideration of such a problem. Even if the radiation detector is deformed in accordance with the surface shape of the subject using a flexible radiation detector, at least each pixel is detected. It is an object of the present invention to provide a radiation detection apparatus and a radiation imaging system that can correct sensitivity to a certain level and obtain a high-quality radiation image.

  A radiation detection apparatus according to a first aspect of the present invention includes a flexible substrate and a plurality of pixels formed on an imaging region of the flexible substrate, detects radiation transmitted through a subject, and generates a radiation image. A flexible radiation detector for converting information, angle detection means for detecting a local tilt angle of the radiation detector associated with the deformation of the radiation detector, and based on the detected local tilt angle And correction means for correcting at least the sensitivity of each pixel of the radiation detector.

  A radiation imaging system according to a second aspect of the invention includes the above-described radiation detection apparatus according to the first aspect of the invention, a radiation source that outputs the radiation, and a control device that controls the radiation source and the radiation detection apparatus. It is characterized by having.

  As described above, according to the radiation detection apparatus and the radiography system according to the present invention, even if the radiation detector is deformed following the surface shape of the subject using a flexible radiation detector, At least the sensitivity of each pixel can be corrected to be constant, and a high-quality radiation image can be obtained.

  Embodiments of a radiation detection apparatus and a radiation imaging system according to the present invention will be described below with reference to FIGS.

  First, as shown in FIG. 1, a radiation imaging system 10 according to the present embodiment includes a radiation source 16 for irradiating a subject (for example, a patient 14) with radiation 12 having a dose according to imaging conditions. The radiation detection device 18 according to the present embodiment, the display device 20 that displays radiation image information based on the radiation 12 detected by the radiation detection device 18, the radiation detection device 18, the radiation source 16, and the display device 20 are provided. The console 22 (control apparatus) to control is provided. Between the console 22 and the radiation detection device 18, the radiation source 16, and the display device 20, for example, UWB (Ultra Wide Band), IEEE 802.11. Signals are transmitted and received by wireless communication using a wireless LAN such as a / g / n or millimeter waves. The console 22 is connected to a radiology information system (RIS) 24 that comprehensively manages radiographic image information and other information handled in the radiology department in the hospital, and the RIS 24 is connected to medical information in the hospital. A medical information system (HIS) 26 for comprehensively managing information is connected.

  As shown in FIG. 1, a radiation detection apparatus 18 according to the present embodiment includes a flexible radiation detector 30 that detects radiation 12 transmitted through a subject 14 and converts it into radiation image information, and the radiation detector. 30 and a plurality of solid block bodies 32 arranged two-dimensionally.

  The radiation detector 18 includes a battery 34 that is a power source of the radiation detector 30, a control unit 36 that drives and controls the radiation detector 30 with electric power supplied from the battery 34, and the radiation detector 30. A transmitter / receiver 38 that transmits / receives a signal including information of the detected radiation 12 to / from the console 22, and an incident angle that detects an incident angle of the radiation 12 to each pixel of the radiation detector 30 due to deformation of the radiation detector 30. A detection unit 110 and a sensitivity correction unit 112 that is incorporated in the control unit 36 and corrects the sensitivity of each pixel of the radiation detector 30 based on the incident angle are accommodated. The battery 34 supplies power to at least the radiation detector 30, the control unit 36, and the transceiver 38.

  The incident angle detection unit 110 includes a plurality of pressure sensors 114 (typically one pressure sensor 114 shown in FIG. 1) installed at the boundary portion between adjacent solid block bodies 32, but actually a plurality of pressure sensors. 114 is installed), and is included in the control unit 36, and has a calculation unit 116 that obtains an incident angle from the outputs of the plurality of pressure sensors 114. The pressure sensor 114 may be any sensor that can detect pressure, deflection, strain, and the like at the boundary portion of the solid block body 32. For example, a metal resistor type (metal wire, metal foil, etc.), semiconductor type, piezoelectric An element type, surface acoustic wave type, magnetostrictive type, optical fiber type, etc. strain gauge, piezoelectric sensor (for example, a thin sheet-like soft sheet-like piezoelectric sensor), etc. can be preferably used.

  Here, a specific example of the radiation detection apparatus 18 will be described with reference to FIGS.

  First, as shown in FIG. 2, the radiation detector according to the first specific example (hereinafter referred to as the first radiation detector 18A) is arranged on the radiation detector 30 and the radiation detector 30 described above. And a plurality of first solid block bodies 32A.

  As shown in FIG. 3, the radiation detector 30 includes a flexible substrate 40, and a TFT on which a scintillator 42 and an array of thin film transistors (TFTs) are formed on the flexible substrate 40. The layer 44 and the photoelectric conversion layer 46 are laminated in this order.

The scintillator 42 is composed of a phosphor such as GOS (Gd ₂ O ₂ S) or CsI that once converts the radiation 12 (see FIG. 1) transmitted through the subject 14 into visible light. The TFT layer 44 is formed with an array of thin film transistors (TFT 52: see FIG. 4), and can transmit the radiation 12 and visible light. The photoelectric conversion layer 46 converts the visible light into an electrical signal using a solid detection element (hereinafter also referred to as a pixel 50) made of a substance such as amorphous silicon (a-Si).

  Examples of the constituent material of the flexible substrate 40 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (for example, Kapton (registered trademark) of DuPont), polysulfone ether, as shown in Patent Document 1, for example. (PES), polycarbonate and the like can be used.

  The radiation detector 30 is entirely covered with a light shielding film 48 so that external light does not enter the photoelectric conversion layer 46. The light shielding film 48 may be formed on the radiation detector 30 using a lamination method, a molding method, or the like.

  For example, as shown in FIG. 4, the radiation detector 30 includes a photoelectric conversion layer 46 in which each pixel 50 made of a substance such as a-Si that converts visible light into an electrical signal is formed by an array of TFT-shaped arrays 52 ( It has a structure arranged on the TFT layer 44). In this case, in each pixel 50, electric charges generated by converting visible light into electric signals are accumulated, and the electric charges can be read out as image signals by sequentially turning on the TFTs 52 for each row.

  A gate line 54 extending parallel to the row direction and a signal line 56 extending parallel to the column direction are connected to the TFT 52 connected to each pixel 50. Each gate line 54 is connected to a row selection scanning unit 58, and each signal line 56 is connected to a column selection scanning unit 60. The column selection scanning unit 60 includes an amplifier 62 connected to each signal line 56, a sample hold circuit 64, and a multiplexer 66 that performs selective scanning on the signal line 56.

  Control signals Von and Voff for controlling on / off of the TFTs 52 arranged in the row direction are supplied from the row selection scanning unit 58 to the gate line 54. In this case, the row selection scanning unit 58 includes a plurality of switches SW1 for switching the gate lines 54, and an address decoder 67 that outputs a selection signal for selecting one of the switches SW1. An address signal is supplied from the control unit 36 to the address decoder 67.

  In addition, the charge held in each pixel 50 flows out to the signal line 56 through the TFTs 52 arranged in the column direction. This electric charge is amplified by the amplifier 62 and supplied to the multiplexer 66 through the sample and hold circuit 64. The multiplexer 66 includes a plurality of switches SW2 for switching the signal line 56, and an address decoder 68 for outputting a selection signal for selecting one of the switches SW2. An address signal is supplied from the control unit 36 to the address decoder 68. An A / D converter 70 is connected to the multiplexer 66, and radiation image information converted into a digital signal by the A / D converter 70 is supplied to the control unit 36.

  Further, as shown in FIG. 1, the control unit 36 of the first radiation detection apparatus 18 </ b> A includes an address signal generation unit 72, an image memory 74, a data memory 76, the above-described calculation unit 116, and a sensitivity correction unit 112. Is provided.

  The address signal generation unit 72 supplies an address signal to the address decoder 67 of the row selection scanning unit 58 and the address decoder 68 of the multiplexer 66 constituting the radiation detector 30. For example, as shown in FIG. 16, the image memory 74 stores the radiation image information Dg detected by the radiation detector 30 in the first storage area 74a. The data memory 76 includes ID information for specifying the first radiation detection device 18A, a map 118 used for calculating the tilt angle, and an incident angle information table storing the calculated incident angles for each pixel. 120 etc. are memorized.

  The transceiver 38 transmits the ID information stored in the data memory 76 and the radiation image information stored in the image memory 74 to the console 22 by wireless communication.

  On the other hand, as shown in FIG. 2, the plurality of first solid block bodies 32A in the first radiation detection apparatus 18A have a rectangular shape as viewed from above, and the length of the long side 78 is at least a radiation detector. 30 having a length of one side 80, and arranged in a direction perpendicular to one side 80 of the radiation detector 30 (y direction in FIG. 2). The plurality of first solid block bodies 32 </ b> A are arranged on the surface (irradiation surface 30 a) of the radiation detector 30 that is irradiated with the radiation 12. Further, as shown in FIG. 3, a heat insulating material 82 is installed inside the first solid block body 32A. Examples of the heat insulating material 82 include polystyrene foam and air.

  Further, in the first solid block body 32A, a surface facing the other adjacent first solid block body 32A is a tapered surface 84, and the distance between the opposed tapered surfaces 84 gradually increases as the distance from the radiation detector 30 increases. It is getting bigger.

  Furthermore, the pressure sensors 114 are respectively installed on the lower surfaces of the adjacent first solid block bodies 32A and across the first solid block bodies 32A. These pressure sensors 114 are components of the incident angle detection unit 110. The installation position of the pressure sensor 114 is not limited to this. For example, as shown in FIG. 5, the pressure sensor 114 may be installed at a portion (bottom) where the opposing tapered surfaces 84 of the adjacent first solid block bodies 32A are closest. .

  In the radiation detector 30, pixels 50 are arranged in regions corresponding to the bottom surfaces 86 of the plurality of first solid block bodies 32A. In this case, as shown in FIG. 6, the arrangement pitch Pa of the pixels 50 in the region corresponding to each bottom surface of the first solid block body 32A is substantially the same as the arrangement pitch Pb of the pixels 50 between the regions. Yes.

  Therefore, when an external force is applied to the first radiation detection device 18A, the first radiation block is bent at the boundary between the first solid block bodies 32A. The bending is stopped at the stage where each tapered surface 84 of the first solid block body 32A is in contact. If the first solid block bodies 32A having a small width are arranged, the range of the curvature change in the entire first radiation detection device 18A can be increased accordingly, and the first solid block bodies 32A having a large width can be arranged. For this reason, the range of change in curvature of the entire first radiation detection apparatus 18A can be reduced accordingly. Of course, the change range of the curvature of the entire first radiation detection apparatus 18A can be arbitrarily set by appropriately changing the inclination angle θ of the tapered surface 84 and the height h of the first solid block body.

  Further, as shown in FIG. 7, when the adjacent first solid block bodies 32A are bent in a direction in which they are close to each other, a pressure corresponding to the bending amount is applied to the pressure sensor 114. An electric signal (pressure detection signal) having a signal level corresponding to the amount is output. In this case, the amount of bending increases in inverse proportion to the angle φ formed by each tapered surface 84 of the adjacent first solid block body 32A. If one of the first solid block bodies 32A is placed on the horizontal surface 122 and the other first solid block body 32A adjacent to the first solid block body 32A is inclined, as shown in FIG. It increases in proportion to the inclination angle θa.

  In this case, the deformation of the entire first radiation detection apparatus 18A is deformed only in the direction orthogonal to the longitudinal direction of the first solid block body 32A (see the y direction in FIG. 2), and the longitudinal direction of the first solid block body (see FIG. 2 (refer to the x direction of 2), the first radiation detector 18A can be installed in a shape that substantially follows the surface shape of the columnar subject 14, for example, the arm of the subject 14 (patient etc.), It can be set so as to cover the legs and the torso, and more information can be obtained as radiation image information.

  Further, even when the first radiation detection apparatus 18A is deformed, since further deformation is prevented by contact between the adjacent first solid block bodies 32A, excessive deformation can be avoided, and the gate line Disconnection of the signal line 54, the signal line 56, and the like can be prevented.

  Moreover, since a large number of pixels 50 constituting the photoelectric conversion layer 46 are located on the bottom surface of the first solid block body 32A, for example, even if an external force is applied to a certain point of one first solid block body 32A, the external force Is not a concentrated load, but is dispersed in the first solid block body 32A and applied as a distributed load to the entire pixels 50 included in the first solid block body 32A. Almost no influence (for example, distortion) occurs. Accordingly, it is possible to omit the image correction process in consideration of the influence of the distortion on the pixel 50.

  In the present embodiment, the first solid block bodies 32A are arranged on the irradiation surface 30a, and the heat insulating material 82 is installed inside the first solid block body 32A. For example, there is almost no influence on the pixel 50 due to a temperature difference between a portion where the subject 14 is in contact and a portion where the subject 14 is not in contact, and the image correction processing considering the temperature change can be omitted.

  As described above, since it is possible to omit the correction process of the image in consideration of the influence of the pressure on the pixel 50 and the temperature change, it is possible to increase the speed of the image process in the console 22 and the like, and whether or not re-shooting is necessary. The simple image processing for discriminating the image can be speeded up, and the efficiency of photographing work can be improved.

  Here, the mounting of the electronic circuit 88 in the first radiation detection apparatus 18A will be described with reference to FIGS.

  First, on the flexible substrate 40 of the radiation detector 30, a first flexible region is formed by a bundle of an imaging region 90 in which a large number of pixels 50 are formed and a large number of gate lines 54 wired to the large number of pixels 50. A wiring portion 92 and a second flexible wiring portion 94 formed by a bundle of a large number of signal lines 56 wired to a large number of pixels 50 are formed, and an electronic circuit 88 is provided at the end of the flexible substrate 40. Has been implemented.

  Examples of the electronic circuit 88 include the control unit 36, the transceiver 38, the row selection scanning unit 58, the column selection scanning unit 60, the A / D converter 70, and the battery 34 described above. The first flexible wiring unit 92 is an imaging unit. A position near the other side 96 of the radiation detector 30 from the region 90 (the other side orthogonal to the one side 80 described above) is wired along the other side 96 to the row selection scanning unit 58, and the second flexible wiring. The unit 94 is wired from the imaging region 90 to the column selection scanning unit 60.

  And the electronic circuit 88 is a location corresponding to the bottom surface of the first solid block body 32Ae disposed at least at the end of the radiation detector 30 among the plurality of first solid block bodies 32A as shown in FIG. Has been implemented.

  As shown in FIG. 10, an opening 98 is formed in the bottom surface of the first solid block body 32Ae arranged at the end, and when the first solid block body 32Ae is installed at the end of the radiation detector 30, The circuit 88 enters the inside of the first solid block body 32Ae through the opening 98, and is accommodated in the first solid block body 32Ae. In this case, since the height of the electronic circuit 88 is allowed up to the height ha inside the first solid block body 32Ae, as the electronic circuit 88, in addition to a film-shaped electronic circuit, a chip-shaped electronic component or a solid electronic An electronic circuit using elements or the like can be used, the range of circuit configuration selection can be expanded, and the degree of freedom in design can be increased.

  As another example, as shown in FIG. 11, an electronic circuit 88 is mounted in advance in the first solid block body 32Ae installed at the end, and a number of terminals (not shown) from the electronic circuit 88 are mounted. To the bottom side of the first solid block body 32Ae. Meanwhile, a large number of terminals (not shown) of the first flexible wiring portion 92 and a large number of terminals (not shown) of the second flexible wiring portion 94 formed in the radiation detector 30 are connected to the first solid block body 32Ae. Positioning is formed at the end of the radiation detector 30 in accordance with the arrangement pitch of a large number of terminals drawn to the bottom surface side. Then, by installing the first solid block body 32Ae, in which the electronic circuit 88 is mounted inside, at the end of the radiation detector 30, the corresponding terminals are electrically connected to each other. Reading is possible.

  In this case, since it is not necessary to mount the electronic circuit 88 on the radiation detector 30, the manufacture of the radiation detector 30 is facilitated. However, although positioning of a large number of terminals is troublesome, electrical connection between the large number of terminals can be facilitated by using a connector in which the arrangement pitch of the terminals is set in advance.

  If a lead plate is installed on the upper surface or the back surface (inner surface) of the upper surface of the first solid block body 32Ae installed at this end, damage to the electronic circuit 88 due to radiation 12 is avoided. be able to.

  In the above-described example, the electronic circuit 88 is collectively mounted on the end of the radiation detector 30. However, as shown in FIG. The divided row selection scanning unit 58a is connected to the series, and the position corresponding to the end of each first solid block body 32A, for example, the other side of the radiation detector 30 You may make it mount in the position near 96 (other side orthogonal to the one side 80 mentioned above). As described above, the mounting method may be on the radiation detector 30 or inside the first solid block body 32A. The divided row selection scanning unit 58a may be mounted corresponding to all the first solid block bodies 32A, or mounted corresponding to a part of the first solid block bodies 32A such as every other one. You may make it do.

  Then, a plurality of rows of gate lines 54 respectively assigned to each first solid block body 32A are wired to the corresponding divided row selection scanning unit 58a. That is, a large number of gate lines 54 are divided into grooves corresponding to the divided row selection scanning unit 58a (groove wiring). In order to avoid damage to the divided row selection scanning unit 58a due to the radiation 12, lead plates are respectively provided in portions of the first solid block bodies 32A corresponding to positions where the divided row selection scanning unit 58a is mounted. You may make it install.

  In this example, since the row selection scanning unit 58 is distributed to each first solid block body 32A, the number of electronic circuits 88 mounted on the end of the radiation detector 30 can be reduced. This leads to an increase in the number of pixel points, and for example, it can sufficiently correspond to a long radiation detector used when photographing the entire spine or the entire foot.

  By the way, in radiography, it is preferable to install a grid for removing scattered radiation. Therefore, in this embodiment, as shown in FIG. 13, the grid is divided into a plurality of divided grids 100 that are divided corresponding to the plurality of first solid block bodies 32 </ b> A related to the imaging region 90 (see FIG. 9). Prepare and install the divided grid 100 inside each first solid block body 32A. The part where the divided grid 100 is installed is an area corresponding to the imaging area 90 excluding the electronic circuit 88. Therefore, the size (outside area) of each divided grid 100 is substantially equal to the area obtained by dividing the imaging region 90 by the number of the first solid block bodies 32A on which the divided grid 100 is installed. Thereby, it is possible to provide a flexible first radiation detection apparatus 18A in which a grid is embedded.

  In the first radiation detection apparatus 18A described above, when the first radiation detection apparatus 18A is not used, as shown in FIG. 14, it can be formed into a compact cylindrical shape by winding it in a spiral shape. It can be stored or stored on a shelf or the like. This can provide an examination space in which the first radiation detection device 18A is housed in a compact manner, and work related to radiography can be performed smoothly.

  In addition, if a flexible handle is installed in the end surface along the longitudinal direction of 1st solid block body 32Ae installed in the edge part, and a hook is provided in the back surface of the radiation detector 30, 1st radiation detection apparatus will be provided. When the handle 18A is wound, it is possible to maintain the wound state by hooking the handle on the hook, which facilitates storage and the like.

  Next, the incident angle detection unit 110 and the sensitivity correction unit 112 will be described with reference to FIGS.

  First, when radiography is performed using the first radiation detection device 18A, the first radiation detection device 18A is installed so that the irradiation surface 30a of the radiation detector 30 faces the radiation source 16. At this time, among the distances between a large number of pixels 50 arranged in the imaging region 90 (see FIG. 9) of the radiation detector 30 and the radiation source 16, for example, the distance between the pixel located in the central portion and the radiation source 16 is the shortest. It is installed to become. For example, the first radiation detector 18A is installed at a predetermined position between the patient 14 and the bed with the surface on which the first solid block bodies 32A are arranged facing the radiation source 16 side.

  At this time, for example, when photographing the chest or spine of the patient 14, the first radiation detection device 18A is installed such that the longitudinal direction of the first solid block body 32A is along the body axis of the patient 14. As a result, the entire first radiation detection apparatus 18A is deformed into an arc shape, for example, substantially following the shape of the back surface of the patient 14.

  At this time, as shown in FIG. 15, when it is assumed that the radiation source 16 is a point light source, a line segment 124 from the radiation source 16 to the center of one first solid block body 32A is the first solid block. In the case of the normal of the body 32A (incident angle 0 °), the sensitivity of the plurality of pixels 50 included in the first solid block body 32A is the maximum sensitivity, and no correction is necessary. However, if the line segment 124 is inclined with respect to the normal line, when the incident angle at this time is θb, the dose is reduced by cos (θb), and thus the sensitivity is lowered accordingly. Therefore, the present embodiment corrects a decrease in sensitivity due to the deformation of the first radiation detection apparatus 18A.

  As illustrated in FIG. 16, the calculation unit 116 of the incident angle detection unit 110 is inclined with respect to the reference plane for each first solid block body 32 </ b> A arranged in the radiation detector 30 based on outputs from the plurality of pressure sensors 114. An inclination angle calculation unit 126 that calculates an angle, and a reference inclination angle θn that is set in advance for each first solid block body 32A and whose direction from each first solid block body 32A to the radiation source 16 is a normal direction are arranged. Based on the map 118 and the tilt angle for each first solid block body 32A obtained by the tilt angle calculator 126, the incident angle calculator obtains the incident angle for each pixel and stores it in the incident angle information table 120. 128. If the radiation source 16 is a surface light source, the reference inclination angle θn is fixed at 0 °.

  The reference surface corresponds to a flat irradiation surface 30a formed when the first radiation detection apparatus 18A is placed on a flat surface, and is a surface having the same concept as the horizontal surface 122 shown in FIG. Therefore, it will be referred to as a reference plane 122 hereinafter.

  In the map 118, when the first solid block body 32A including the central pixel of the imaging region 90 among the plurality of first solid block bodies 32A is set as the reference block body 32Ac (see FIG. 15), for example, as shown in FIG. The number of the first solid block bodies 32A arranged in the radiation detector 30 is the same as the number of records, and each record includes the number of the first solid block body and a plurality of pixels included in the first solid block body. Coordinates (m rows and n columns: m = 0, 1, 2,..., N = 0, 1, 2,...), The distance from the center of the reference block body 32Ac to the center of the first solid block body 32A, The reference inclination angle θn and the inclination angle are stored. Among these, the number of the first solid block body 32A, the coordinates of a plurality of pixels included in the first solid block body 32A, and the distance from the center of the reference block body 32Ac to the center of the first solid block body 32A are registered at the time of manufacture. The other parameters (reference tilt angle θn and tilt angle) are stored during the calculation process by the tilt angle calculation unit 126.

  If the radiation source 16 is a point light source, the reference inclination angle θn is obtained as follows. That is, when the shortest distance from the radiation source 16 to the radiation detector 30 is La, and the distance between the center of the first solid block body 32A and the center of the reference block body 32Ac is Lb, the radiation source 16 is used as a reference, and Then, an intersection 134 of the first arc 130 having the radius of the shortest distance La and the second arc 132 having the radius of the distance Lb and the center of the reference block body 32Ac is obtained, and the intersection 134 is used as a contact point. The angle formed between the tangent 136 on the first arc 130 and the reference plane 122 is the reference inclination angle θn. Therefore, since the distance Lb is known at the time of manufacture, if the shortest distance La is known, the reference inclination angle θn in each first solid block body 32A can be obtained. The obtained reference inclination angle θn is stored in each corresponding record of the map 118.

  For example, if the shortest distance La is determined as a fixed value in advance, the fixed value may be registered in the data memory 76. Alternatively, if the shortest distance La changes every time an image is taken, a doctor or a radiologist inputs using a keyboard or other input device connected to the console 22, so that the first radiation detector 18 </ b> A is wirelessly communicated. The data may be stored in the data memory 76. Alternatively, the shortest distance La may be calculated based on imaging information captured with a ruler or the like by a digital camera installed outside and stored in the data memory 76 of the first radiation detection apparatus 18A by wireless communication.

  Here, processing in the calculation unit 116 (inclination angle calculation unit 126 and the like) and the sensitivity correction unit 112 of the incident angle detection unit 110 will be described with reference to the flowchart of FIG.

  First, in step S1 of FIG. 18, the inclination angle of each first solid block body 32A is calculated. For convenience, in FIG. 15, the reference block body 32Ac is the reference block 32Ac, the first solid block body 32A adjacent to one of the reference blocks 32Ac is the first block 32A1, and the first block 32A1 is adjacent to the outside of the first block 32A1. The first solid block body 32A is referred to as a second block 32A2, and the first solid block body 32A adjacent to the outside of the second block 32A2 is referred to as a third block 32A3.

  The inclination angle of the reference block 32Ac is set as 0 °. The inclination angle (first inclination angle) of the first block 32A1 is obtained based on the output from the pressure sensor 114 installed between the reference block 32Ac and the first block 32A1.

  The inclination angle (second inclination angle) of the second block 32A2 is obtained by adding the first inclination angle to the inclination angle obtained based on the output from the pressure sensor 114 installed between the first block 32A1 and the second block 32A2. It is obtained by doing.

  Similarly, the inclination angle (third inclination angle) of the third block 32A3 is set to the inclination angle obtained based on the output from the pressure sensor 114 installed between the second block 32A2 and the third block 32A3. It is obtained by adding the corners. The same applies hereinafter.

  In the above-described example, the first solid block body 32A arranged on one side of the reference block 32Ac has been described. However, the same processing as described above is performed on the first solid block body 32A arranged on the other side of the reference block 32Ac. Is called.

  The obtained first tilt angle, second tilt angle, third tilt angle,... Are stored in the corresponding records of the map 118.

  The tilt angle calculation unit 126 incorporates a calculation method (algorithm) for obtaining the tilt angle described above, for example, as software.

  Next, in step S <b> 2 of FIG. 18, the incident angle calculation unit 128 calculates the incident angle θa for all the pixels 50 by performing the following calculation for each record of the map 118 and registers it in the incident angle information table 120. The incident angle information table 120 has the same number of records as the number of all pixels, and stores the incident angle θa of the pixel 50 corresponding to each record.

  That is, regarding one record (for example, record 1) of the map 118, information on the reference inclination angle θn and the inclination angle is read from the record 1, and the following calculation is performed.

Incident angle θa = | reference inclination angle θn−inclination angle |
The obtained incident angle θa is stored in each record corresponding to the plurality of pixels 50 included in the record 1 in the incident angle information table 120. At this time, the coordinates are stored in the corresponding record while referring to the coordinates of the pixel 50 registered in the record 1.

  This process is performed for all the records of the map 118, whereby the incident angle θa is determined for each of the pixels 50.

  Next, in step S <b> 3 in FIG. 18, the sensitivity correction unit 112 reads out pixel values from the radiation image information Dg stored in the first storage area 74 a of the image memory 74, and further stores the incident values stored in the data memory 76. The incident angle θa is read from each angle information table 120, and the sensitivity is corrected by performing the following calculation.

  That is, when the pixel value read from the radiation image information Dg is Da and the incident angle of the pixel corresponding to the pixel value read from the incident angle information table 120 is θa, Da / cos (θa) is obtained and the obtained value Is the pixel value of the pixel 50.

  The radiation image information dDg whose sensitivity has been corrected is stored in the second storage area 74 b of the image memory 74.

  The first radiation detection apparatus 18A and the radiation imaging system 10 are basically configured as described above, and the operation thereof will be described next.

  Patient information of the patient 14 (subject) to be imaged is registered in advance in the console 22 prior to imaging. If the imaging region and imaging method are determined in advance, these imaging conditions are also registered in advance.

  When radiographic image information is taken in an operating room, medical examination, or a round in a hospital, for example, as described above, a doctor or a radiographer places the first solid at a predetermined position between the patient 14 and the bed. The first radiation detection apparatus 18A is installed with the surface on which the block bodies 32A are arranged facing the radiation source 16 side. At this time, the entire first radiation detection apparatus 18A is deformed into an arc shape substantially following the surface shape of the back of the patient 14, for example. The inclination angle calculation unit 126 of the incident angle detection unit 110 obtains the inclination angle of each first solid block body 32A based on the output from each pressure sensor 114, and the incident angle calculation unit 128 obtains each first solid obtained. The incident angle θa of all the pixels 50 is obtained based on the inclination angle of the block body 32A.

  Next, after appropriately moving the radiation source 16 to a position facing the first radiation detection device 18A, the doctor or the radiologist operates the imaging switch of the radiation source 16 to perform imaging. Based on the operation of the imaging switch, the radiation source 16 requests transmission of imaging conditions to the console 22 by wireless communication, and the console 22 relates to the imaging region of the patient 14 based on the received request. The imaging conditions are transmitted to the radiation source 16. When receiving the imaging conditions, the radiation source 16 irradiates the patient 14 with radiation 12 having a predetermined dose according to the imaging conditions.

  The radiation 12 transmitted through the patient 14 is irradiated to the radiation detector 30 after the scattered radiation is removed by the grid (a plurality of divided grids 100) of the first radiation detection apparatus 18A. The scintillator 42 constituting the radiation detector 30 emits visible light having an intensity corresponding to the intensity of the radiation 12, and each pixel 50 constituting the photoelectric conversion layer 46 converts the visible light into an electric signal and accumulates it as an electric charge. To do. Next, the charge information, which is the radiation image information of the patient 14 held in each pixel 50, is supplied from the address signal generation unit 72 of the control unit 36 to the row selection scanning unit 58 and the multiplexer 66 of the column selection scanning unit 60. Read according to the signal.

  That is, the address decoder 67 of the row selection scanning unit 58 outputs a selection signal according to the address signal supplied from the address signal generation unit 72, selects one of the switches SW1, and the TFT 52 connected to the corresponding gate line 54. A control signal Von is supplied to the gates of the two. On the other hand, the address decoder 68 of the multiplexer 66 outputs a selection signal in accordance with the address signal supplied from the address signal generation unit 72, sequentially switches the switch SW2, and is connected to the gate line 54 selected by the row selection scanning unit 58. Radiation image information Dg, which is charge information held in each pixel 50, is sequentially read out via a signal line 56.

  The radiation image information Dg read from each pixel 50 connected to the selected gate line 54 of the radiation detector 30 is amplified by each amplifier 62 and then sampled by each sample and hold circuit 64. To the A / D converter 70 and converted into a digital signal. The radiation image information Dg converted into the digital signal is temporarily stored in the first storage area 74a of the image memory 74 of the control unit 36.

  Similarly, the address decoder 67 of the row selection scanning unit 58 sequentially switches the switch SW1 according to the address signal supplied from the address signal generation unit 72, and the charge held in each pixel 50 connected to each gate line 54. The radiation image information Dg, which is information, is read out through the signal line 56 and stored in the first storage area 74 a of the image memory 74 of the control unit 36 through the multiplexer 66 and the A / D converter 70.

  At this time, the sensitivity correction unit 112 of the present embodiment sets the incident angle θa of all the pixels 50 obtained by the incident angle calculation unit 128 with respect to the radiation image information Dg stored in the first storage area 74a. Based on this, the sensitivity is corrected, and the corrected radiation image information dDg is stored in the second storage area 74 b of the image memory 74.

  The radiation image information Dg stored in the first storage area 74a of the image memory 74 and the radiation image information dDg after sensitivity correction stored in the second storage area 74b are transmitted to the console 22 by wireless communication via the transceiver 38. Sent. The console 22 performs predetermined image processing on the received radiation image information Dg and dDg, and then stores the radiation image information in association with the registered patient information of the patient 14. The radiographic image information subjected to the image processing is transmitted from the console 22 to the display device 20, and the display device 20 displays the radiographic image information.

  As described above, according to the first radiation detection apparatus 18A, even if the radiation detector 30 is deformed following the surface shape of the subject 14 using the flexible radiation detector 30, each pixel The sensitivity of 50 can be corrected to be constant, and a high-quality radiation image can be obtained. Further, excessive deformation of the radiation detector 30 can be avoided, there is no occurrence of image distortion or disconnection in the radiation image information, reliability can be improved, and convenience, storage, etc. The convenience will be excellent.

  In the first radiation detection apparatus 18A, the scintillator 42, the TFT layer 44, and the photoelectric conversion layer 46 are laminated on the flexible substrate 40 in this order (the photoelectric conversion layer 46, the TFT layer 44, and the scintillator with respect to the irradiation surface 30a). 42), visible light generated by the scintillator 42 can be efficiently converted into an electrical signal by the photoelectric conversion layer 46. As a result, high-quality radiation image information can be obtained. . Of course, the laminated structure shown in FIG. 19 may be used instead of the laminated structure shown in FIG. That is, the TFT layer 44, the photoelectric conversion layer 46, and the scintillator 42 may be laminated in this order from the flexible substrate 40 toward the irradiation surface 30a.

  In addition, the first solid block body 32A is installed on the irradiation surface 30a of the radiation detector 30, but it may be installed on the surface opposite to the irradiation surface 30a of the radiation detector 30. .

  Furthermore, in the present embodiment, since signals are transmitted and received by radio communication between the console 22, the first radiation detection device 18A, the radiation source 16, and the display device 20, a cable for transmitting and receiving signals is provided. It becomes unnecessary and there is no risk of disturbing the work of doctors or radiographers. Therefore, the doctor or radiologist can perform his / her work efficiently.

  By the way, when pressure is applied to the scintillator 42, the electrostatic capacity for accumulating signal charges changes, so that the dark current characteristics and sensitivity characteristics change. Also, depending on the phosphor, the amount of light emission changes due to a load, and as a result, the sensitivity varies locally. In particular, depending on how the pixels are arranged on the photoelectric conversion layer 46, the pixel may be arranged at the boundary portion of the first solid block body 32A. In this case, when the first radiation detection device 18A is deformed and the adjacent first solid block bodies 32A are bent in a direction approaching each other, the pixels 50 arranged at the boundary portion of the adjacent first solid block bodies 32A include: A pressure greater than that of the pixel 50 installed at a position corresponding to the bottom surface of the first solid block body 32A may be applied, and the sensitivity and dark current characteristics may change greatly.

  Therefore, in the present embodiment, as shown in FIG. 20, the change in dark current with respect to pressure for one pixel 50 measured in advance is stored in the data memory 76 as the dark current information table 140, and further measured in advance. A change in sensitivity with respect to pressure for one pixel 50 is stored in the data memory 76 as a sensitivity information table 142. In addition, a pixel information table 144 in which addresses of the pixels 50 arranged at the boundary portion of the first solid block body 32A are registered, and a pressure value applied to the pixels 50 arranged at the boundary portion of the first solid block body 32A are stored. The pressure information table 146 is recorded in the data memory 76. In addition to the incident angle detection unit 110, a pressure value calculation unit 148 and a second correction unit 150 are provided.

  Here, processing in the pressure value calculation unit 148 and the second correction unit 150 will be described with reference to the flowchart of FIG.

  First, in step S101 of FIG. 21, the pressure value calculation unit 148 determines the adjacent first solid block body 32A based on the inclination angle stored in the map 118 for each first solid block body 32A by the inclination angle calculation unit 126. The pressure value applied to the boundary portion is calculated. In the present embodiment, since the pressure sensor 114 is installed at the boundary portion between the adjacent first solid block bodies 32A, the detection output from the pressure sensor 114 may be directly used as the pressure value. In this case, the calculation process can be speeded up.

  Next, in step S <b> 102 of FIG. 21, the pressure value calculation unit 148 associates the pressure value obtained as described above with the address of the pixel 50 registered in the pixel information table 144 and registers it in the pressure information table 146. .

  In step S103 of FIG. 21, the second correction unit 150 determines the luminance of the pixel 50 registered in the pressure information table 146 among the pixels 50 of the radiation image information Dg recorded in the first storage area 74a. The value is corrected with reference to the corresponding pressure value, dark current information table 140, and sensitivity information table 142. That is, the influence of dark current characteristics and sensitivity characteristics on some of the pixels 50 due to local pressure is eliminated by this correction, and the dark current characteristics and sensitivity of each pixel 50 in the imaging region 90 are eliminated. Each characteristic is constant. The corrected radiation image information dDg is stored in the second storage area 74 b of the image memory 74.

  In the present embodiment, radiography is performed based on the operation of the imaging switch of the radiation source 16 by the doctor or radiographer. However, radiography is performed based on the operation of the console 22 by the doctor or radiographer. It may be.

  Furthermore, in this embodiment, instead of the above-described configuration, for example, the dose of the incident radiation 12 is directly converted into an electric signal by a photoelectric conversion layer using a solid detection element made of a substance such as amorphous selenium (a-Se). May be converted to In this case, the formation of the light shielding film 48 can be omitted.

  Also, radiation image information can be obtained by using a light conversion type radiation detector. In this light conversion type radiation detector, when radiation is incident on each solid detection element arranged in a matrix, an electrostatic latent image corresponding to the dose is accumulated and recorded in the solid detection element. When reading the electrostatic latent image, the radiation detector is irradiated with reading light by a flexible organic EL (electroluminescence) or the like, and the value of the generated current is acquired as radiation image information. The radiation detector can erase and reuse the radiation image information that is the remaining electrostatic latent image by irradiating the radiation detector with erasing light (refer to Japanese Patent Laid-Open No. 2000-105297). .

  Furthermore, when the first radiation detection apparatus 18A is used in an operating room or the like, there is a risk that blood or other germs may adhere. Therefore, the first radiation detection device 18A can be used repeatedly and repeatedly by making the first radiation detection device 18A waterproof and hermetically sealed and, if necessary, sterilized and washed. Of course, the first solid block body 32A may be detachable from the radiation detector 30 by installing, for example, a hook-and-loop fastener on the bottom surface of the first solid block body 32A and the irradiation surface of the radiation detector 30. . As a result, the first solid block body 32A and the radiation detector 30 can be easily cleaned and the first solid block body 32A can be removed when applied to a light conversion type radiation detector. There is also an advantage that reading is easy.

  In addition, the wireless communication between the first radiation detection apparatus 18A and the external device may be performed by optical wireless communication using infrared rays or the like instead of normal communication using radio waves.

  In the radiation detector 30 described above, an example using the TFT 52 has been described. Alternatively, the radiation detector 30 may be implemented in combination with another imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. Furthermore, it can be replaced by a CCD (Charge-Coupled Device) image sensor that transfers charges while shifting the charges by a shift pulse corresponding to the gate signal referred to in the TFT 52.

  Next, a radiation detection apparatus (hereinafter referred to as a second radiation detection apparatus 18B) according to a second embodiment will be described with reference to FIGS.

  As shown in FIG. 22, the second radiation detection device 18B has substantially the same configuration as the first radiation detection device 18A described above, but the plurality of solid block bodies 32 each have a rectangular shape when viewed from above. However, it is different in that the second solid block bodies 32B are arranged in a matrix with respect to the radiation detector 30. That is, each second solid block body 32B has, for example, a square frustum shape.

  Therefore, when an external force is applied to the second radiation detection device 18B, the second radiation block 18B bends at the boundary between the adjacent second solid block bodies 32B. The bending is stopped at the stage where each tapered surface 84 of the second solid block body 32B to be contacted. That is, since further deformation is prevented by contact between the adjacent second solid block bodies 32B, excessive deformation can be avoided, and disconnection of the gate line 54, the signal line 56, and the like can be prevented. .

  Unlike the first radiation detection device 18A, the second radiation detection device 18B deforms not only in one direction (the y direction in FIGS. 2 and 22) but also in the x direction, and thus substantially follows a free-form surface. Can be deformed. Therefore, it is possible to radiograph the head and the bent elbow and knee.

  Also in the second radiation detection apparatus 18B, the electronic circuit 88 is disposed at least at the end of the radiation detector 30 among the plurality of second solid block bodies 32B, similarly to the first radiation detection apparatus 18A described above. You may make it mount in the location corresponding to the bottom face of several 2nd solid block body 32Be arranged along one side of a radiation detector, or may mount in 2nd solid block body 32Be. In this case, it is desirable that the electronic circuit 88 has a circuit configuration separated according to the number of the second solid block bodies 32Be.

  Further, the plurality of divided row selection scanning units 58a connected to the series are arranged at positions corresponding to the end portions of the second solid block bodies 32B, for example, the other side 96 of the radiation detector 30 (perpendicular to the one side 80 described above). You may make it mount in the position near other side). As described above, the mounting method may be on the radiation detector 30 or inside the second solid block body 32B.

  Furthermore, a plurality of divided grids 100 that are divided in correspondence with the plurality of second solid block bodies 32B according to the imaging region 90 (see FIG. 9) are prepared, You may make it install the division | segmentation grid 100. FIG.

  Here, an example of an algorithm in the incident angle detection unit 110 applied to the second radiation detection apparatus 18B, in particular, the inclination angle calculation unit 126 will be described.

  First, if the radiation source 16 is a point light source, the reference inclination angle θn of each second solid block body 32B is obtained by a procedure similar to the procedure for obtaining the reference inclination angle θn in the first radiation detection apparatus 18A described above. Can do. If the radiation source 16 is a surface light source, the reference inclination angle θn is 0 °.

  And the inclination | tilt angle of each 2nd solid block body 32B is calculated | required as follows. For convenience, as shown in FIG. 23, the second solid block body 32B including the center pixel of the imaging region 90 is used as a reference block 32Bc, and the second solid block body adjacent to one side in the x direction of the reference block 32Bc is used. The second solid block body adjacent to block x1, block x1 is block x2, the second solid block body adjacent to block x2 is block x3, and the second solid block body adjacent to one of the reference blocks 32Bc in the y direction is blocked. The second solid block body adjacent to y1 and the block y1 is referred to as a block y2, and the second solid block body adjacent to the block y2 is referred to as a block y3. That is, here, in FIG. 23, the second solid block body 32B included in the first region 138a is targeted.

  The pressure sensor 114 is installed, for example, at a boundary portion between the reference block 32Bc and the block x1, a boundary portion between the block x1 and the block x2, a boundary portion between the block x2 and the block x3, and further, for example, a boundary portion between the reference block 32Bc and the block y1. It is installed at the boundary between block y1 and block y2, and at the boundary between block y2 and block y3.

  First, the inclination angle of the reference block 32Bc is set as 0 °. The inclination angle θx1 of the block x1 is obtained based on the output from the pressure sensor 114 installed between the reference block 32Bc and the block x1. The inclination angle θx2 of the block x2 is obtained by adding the inclination angle θx1 to the inclination angle obtained based on the output from the pressure sensor 114 installed between the blocks x1 and x2. Similarly, the inclination angle θx3 of the block x3 is obtained by adding the inclination angle θx2 to the inclination angle obtained based on the output from the pressure sensor 114 installed between the block x2 and the block x3. The same applies hereinafter. Further, the inclination angle θy1 of the block y1, the inclination angle θy2 of the block y2, the inclination angle θy3 of the block y3, and the like can be obtained in the same manner as described above.

  Further, in the second radiation detection apparatus 18B, the block xy11 sandwiched between the block x1 and the block y1, the block xy12 sandwiched between the block x2 and the block y2, the block xy22, the block xy21, the block x3 and the block y3 are sandwiched. The inclination angles of the block xy13, the block xy23, the block xy33, the block xy32, the block xy31, etc. are also obtained.

  For example, the inclination angle of the block xy11 is inclination angle θx1 or inclination angle θy1 if inclination angle θx1 = inclination angle θy1, and if inclination angle θx1 and inclination angle θy1 are different, | inclination angle θx1−inclination angle θy1 | / 2 is obtained, and this value is obtained by adding to a smaller one of the inclination angles θx1 and θy1.

  The inclination angles of the block xy12, the block xy22, and the block xy21 are the inclination angle θx2 or the inclination angle θy2 if the inclination angle θx2 = the inclination angle θy2, and the inclination angle θx2 is different from the inclination angle θy2 θx2−inclination angle θy2 | / 4 is obtained, and this value θk is added in order from the smallest inclination angle of inclination angle θx2 and inclination angle θy2. For example, if the inclination angle θx2 <the inclination angle θy2, the inclination angle of the block xy12 = the inclination angle θx2 + θk, the inclination angle of the block xy22 = the inclination angle θx2 + 2θk, and the inclination angle of the block xy21 = the inclination angle θx2 + 3θk.

  The inclination angles of the block xy13, the block xy23, the block xy33, the block xy32, and the block xy31 are the inclination angle θx3 or the inclination angle θy3 if the inclination angle θx3 = the inclination angle θy3, and the inclination angle θx3 is different from the inclination angle θy3. In this case, | tilt angle θx3−tilt angle θy3 | / 6 is obtained, and this value θm is added in order from the smallest tilt angle of tilt angle θx3 and tilt angle θy3. For example, if the inclination angle θx3 <the inclination angle θy3, the inclination angle of the block xy13 = the inclination angle θx3 + θm, the inclination angle of the block xy23 = the inclination angle θx3 + 2θm, the inclination angle of the block xy33 = the inclination angle θx2 + 3θm, and the inclination angle of the block xy32 = inclination angle θx3 + 4θm and the inclination angle of the block xy31 = the inclination angle θx3 + 5θm. The same applies hereinafter.

  Although the above-mentioned example explained the 2nd solid block object 32B arranged in the 1st field 138a, the processing similar to the above is the other 2nd solid block arranged in the 2nd field 138b-the 4th field 138d. It is also performed on the body 32B.

  The obtained inclination angle θx1, inclination angle θx2, inclination angle θx3, etc. are stored in the corresponding records of the map 118, respectively.

  Note that the processing in the incident angle calculation unit 128, the processing in the sensitivity correction unit 112, and the processing in the pressure value calculation unit 148 and the second correction unit 150 are the same as in the case of the first radiation detection apparatus 18A. Here, the duplicate description is omitted.

  As described above, in the second radiation detection device 18B, similarly to the first radiation detection device 18A, the radiation detector 30 follows the surface shape of the subject 14 using the flexible radiation detector 30. Even if it is deformed, the sensitivity of each pixel 50 can be corrected to be constant, and a high-quality radiation image can be obtained. Further, excessive deformation of the radiation detector 30 can be avoided, there is no occurrence of image distortion or disconnection in the radiation image information, reliability can be improved, and convenience, storage, etc. The convenience will be excellent.

  Of course, the radiation detection apparatus and the radiation imaging system according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.

  For example, at least one first solid block body 32A and a plurality of second solid block bodies 32B may be arranged on the radiation detector 30. As an example, in the second radiation detection apparatus 18B shown in FIG. 22, one first solid block body 32Ae is arranged instead of the plurality of second solid block bodies 32Be on which the electronic circuit 88 is mounted. Also good.

It is a block diagram which shows the radiation detection apparatus and radiography system which concern on this Embodiment. It is a perspective view which shows the external appearance of a 1st radiation detection apparatus. It is a longitudinal cross-sectional view which shows the principal part of a 1st radiation detection apparatus. It is a block diagram which shows the circuit structure of a radiation detector. It is a longitudinal cross-sectional view which shows the other example of the installation position of a pressure sensor. It is explanatory drawing which shows the relationship between a 1st solid block body and the pixel arrangement | sequence of a radiation detector. It is explanatory drawing which shows the relationship between a deformation | transformation of a 1st solid block body, and an inclination angle. It is a graph which shows the relationship between the inclination-angle of a 1st solid block body, and the output of a pressure sensor. It is explanatory drawing which shows an example of the mounting state of the wiring to a radiation detector, and an electronic circuit. It is sectional drawing which abbreviate | omits and shows the state which mounted the electronic circuit in the radiation detector. It is sectional drawing which abbreviate | omits and shows the state which mounted the electronic circuit inside the 1st solid block body. It is explanatory drawing which shows an example of the groove wiring of the gate line corresponding to a 1st solid block body. It is a perspective view which shows the state which installed the division grid inside the 1st solid block body. It is explanatory drawing which shows the state which wound the 1st radiation detection apparatus in the spiral shape. It is a figure for demonstrating the procedure which calculates | requires the inclination-angle of a 1st solid block body. It is a functional block diagram which shows the structure of an incident angle detection part and a sensitivity correction | amendment part. It is explanatory drawing which shows the breakdown of a map. It is a flowchart which shows the process in the calculating parts (inclination angle calculating part etc.) and a sensitivity correction part of an incident angle detection part. It is a longitudinal cross-sectional view which shows the other example of the principal part of a 1st radiation detection apparatus. It is a functional block diagram which shows the example which provided the pressure value calculating part and the 2nd correction | amendment part separately from the incident angle detection part. It is a flowchart which shows the process in a pressure value calculating part and a 2nd correction | amendment part. It is a perspective view which shows the external appearance of a 2nd radiation detection apparatus. It is a figure for demonstrating the procedure which calculates | requires the inclination-angle of the 2nd solid block body corresponding to a 2nd radiation detection apparatus.

Explanation of symbols

10 ... Radiation imaging system 12 ... Radiation 14 ... Subject (patient)
16 ... Radiation source 18 ... Radiation detection device 20 ... Display device 30 ... Radiation detector 32 ... Solid block body 34 ... Battery 36 ... Control unit 38 ... Transceiver 40 ... Flexible substrate 50 ... Pixel 74 ... Image memory 76 ... Data Memory 110 ... Incident angle detector 112 ... Sensitivity corrector 114 ... Pressure sensor 118 ... Map 120 ... Incident angle information table 126 ... Inclination angle calculator 128 ... Incident angle calculator 130 ... First arc 132 ... Second arc 134 ... Intersection 136 ... Tangent line 140 ... Dark current information table 142 ... Sensitivity information table 144 ... Pixel information table 146 ... Pressure information table 148 ... Pressure value calculation unit 150 ... Second correction unit

Claims (15)

A flexible radiation detector having a flexible substrate and a plurality of pixels formed on an imaging region of the flexible substrate and detecting radiation transmitted through the subject and converting the radiation into radiation image information; ,
Angle detection means for detecting a local tilt angle of the radiation detector accompanying deformation of the radiation detector;
A radiation detection apparatus comprising: correction means for correcting at least sensitivity of each pixel of the radiation detector based on the detected local inclination angle. The radiation detection apparatus according to claim 1,
Furthermore, it has an incident angle detection means for detecting an incident angle of the radiation to each pixel of the radiation detector accompanying the deformation of the radiation detector,
The radiation detection apparatus according to claim 1, wherein the correction unit includes a correction unit that corrects sensitivity at each pixel of the radiation detector based on the incident angle. The radiation detection apparatus according to claim 2.
A plurality of solid block bodies arranged two-dimensionally on the radiation detector;
The angle detection means includes a plurality of sensors installed at boundary portions of the adjacent solid block bodies, and a reference plane for each solid block body arranged in the radiation detector based on outputs from the plurality of sensors. An inclination angle calculation unit for calculating an inclination angle with respect to
The incident angle detection means is set in advance for each solid block body, a map in which reference inclination angles are arranged so that the direction from each solid block body to the radiation source is a normal direction, and the inclination angle calculation unit A radiation detection apparatus comprising: an incident angle calculation unit that obtains an incident angle for each pixel based on the obtained inclination angle for each solid block body. The radiation detection apparatus according to claim 3.
The reference inclination angle of the solid block bodies arranged in the map is:
Among the plurality of solid block bodies, a solid block body including a central pixel of the imaging region is set as a reference solid block body,
When the shortest distance from the radiation source to the radiation detector is La, and the distance between the center of the solid block body and the center of the reference solid block body is Lb,
On the first arc having a contact point at the intersection of a first arc having a radius of the shortest distance La with the radiation source as a reference and a second arc having a radius of the distance Lb with the center of the reference solid block body as a reference The radiation detection apparatus is characterized in that the angle is formed by the tangent to the reference plane. The radiation detection apparatus according to claim 3 or 4,
The sensitivity correction unit determines Da / cos (θa) and corrects the pixel value of the pixel, where Da is the pixel value read from the pixel and θa is the incident angle of the corresponding pixel. The radiation detection apparatus characterized by the above-mentioned. The radiation detection apparatus according to claim 2.
Furthermore, based on the detected local inclination angle, it has pressure detection means for detecting the degree of local bending as a pressure value,
The correction means further includes a second correction unit that corrects at least one of local sensitivity and dark current based on the local pressure value. The radiation detection apparatus according to claim 6.
A plurality of solid block bodies arranged two-dimensionally on the radiation detector;
The angle detection means includes a plurality of sensors installed at boundary portions of the adjacent solid block bodies, and a reference plane for each solid block body arranged in the radiation detector based on outputs from the plurality of sensors. An inclination angle calculation unit for calculating an inclination angle with respect to
The pressure detection means detects a pressure value applied to the boundary portion of the solid block body from the calculated inclination angle,
The second correction unit corrects at least one of sensitivity and dark current of a pixel corresponding to a boundary portion of the solid block body based on the detected pressure value. In the radiation detection apparatus of any one of Claims 3-5, 7,
The radiation detector according to claim 1, wherein the sensor is a pressure sensor. The radiation detection apparatus according to any one of claims 3 to 5, 7, and 8,
In the solid block body, a surface facing another adjacent solid block body is a tapered surface, and the distance between the facing surfaces gradually increases as the distance from the radiation detector increases. Radiation detection device. In the radiation detection apparatus of any one of Claims 3-5 and 7-9,
In the radiation detector, pixels are arranged in a region corresponding to each bottom surface of the plurality of solid block bodies,
The incident angle detecting means detects that the incident angles of a plurality of pixels included in the same solid block body are the same, respectively. The radiation detection apparatus according to claim 10.
The radiation detection apparatus, wherein an arrangement pitch of pixels in an area corresponding to each bottom surface of the solid block body and an arrangement pitch of pixels between the areas are substantially the same. In the radiation detection apparatus of any one of Claims 3-5 and 7-11,
Each of the solid block bodies has a rectangular shape when viewed from above, and the length of the long side is at least the length of one side of the radiation detector,
The plurality of solid block bodies are arranged in a direction orthogonal to the one side of the radiation detector. The radiation detection apparatus according to any one of claims 3 to 5 and 7 to 12,
Each of the solid block bodies has a rectangular shape when viewed from above,
A plurality of the solid block bodies are arranged in a matrix with respect to the radiation detector.   A radiation imaging apparatus comprising: the radiation detection apparatus according to claim 1; a radiation source that outputs the radiation; and a control device that controls the radiation source and the radiation detection apparatus. system. The radiation imaging system according to claim 14, wherein
The radiation detection system transmits the radiation image information converted by the radiation detector to the control device by wireless communication.

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