JP5453219B2 - Radiation imaging equipment - Google Patents

Description

  The present invention relates to a radiographic imaging apparatus, and in particular, a scintillator having a columnar crystal structure, which absorbs irradiated radiation and emits light, and a light detection unit that detects light emitted from the scintillator as a radiation image. And a radiographic image capturing apparatus that closely contacts each other via a contact member.

In recent years, radiation sensitive layers have been arranged on TFT (Thin Film Transistor) active matrix substrates to detect irradiated X-rays, γ-rays, α-rays, and other radiation, and to radiation image data representing the distribution of irradiation dose. An FPD (Flat Panel Detector) that directly converts and outputs has been put into practical use. It incorporates a panel-type radiation detector such as this FPD, an electronic circuit including an image memory, and a power supply unit, and is output from the radiation detector. A portable radiation detection panel (hereinafter also referred to as an electronic cassette) that stores radiation image data in an image memory has been put into practical use. As the radiation sensitive layer, for example, irradiated radiation is once converted into light by a scintillator (phosphor layer) such as CsI: Tl, GOS (Gd ₂ O ₂ S: Tb), and emitted from the scintillator. There is known a configuration (indirect conversion method) in which light is reconverted into an electric charge and stored by a photodetection unit including a PD (Photodiode) or the like. Because the radiation detection panel is excellent in portability, the subject can be photographed while being placed on a stretcher or bed, and the position of the radiation detection panel can be easily adjusted to adjust the imaging part, so it cannot move. It is possible to flexibly cope with shooting of the subject.

  Regarding the radiation detection panel described above, Patent Document 1 discloses that the amount of light emitted from a phosphor is transmitted to a photoelectric conversion image sensor in a radiographic apparatus having a structure in which a phosphor layer and a photoelectric conversion image sensor substrate are bonded to each other with an adhesive layer. In order to obtain stable performance over a long period of time without reducing resolution and reducing resolution, the binder polymer of the phosphor layer and the pressure-sensitive adhesive forming polymer are crosslinked with a crosslinking agent contained in the pressure-sensitive adhesive layer. A technique for improving the adhesion between the phosphor layer and the pressure-sensitive adhesive layer is disclosed.

  Further, in Patent Document 2, in a radiographic imaging device, high-frequency noise is removed from an image for image defect detection, a first image defect is detected from the noise-removed image using a first threshold, and the first The second image defect is detected using a second threshold value that is larger than the threshold value, the image defect is detected by adding the first and second image defects, and the increase history of the image defect recorded in the database Discloses a technique for predicting the number of defective pixels, the size, and the density increase rate per unit area, and issuing a warning when at least one predicted value exceeds a threshold value.

  Further, in Patent Document 3, in a radiation image detection apparatus having a configuration in which a radiation conversion sheet and a photoelectric conversion sensor are joined by an adhesive layer (intermediate layer), adhesion between the radiation conversion sheet and the photoelectric conversion sensor is ensured. For the purpose of preventing the occurrence of image unevenness, a technique for setting the haze degree of the intermediate layer in the range of 3 to 50% is disclosed.

JP 2004-309169 A JP 2009-267519 A JP 2010-025780 A

  When CsI is used as the scintillator of the radiation detection panel and the scintillator is configured to have a columnar crystal structure, the light generated by the scintillator along with the irradiation of the radiation travels through the columnar crystal. Since scattering of the emitted light is suppressed, there is an advantage that it is possible to suppress a reduction in the sharpness of the detected image when the irradiated radiation is detected as an image. In the above configuration, in the configuration in which the light detection unit is further arranged on the radiation incident side of the scintillator and the scintillator and the light detection unit are bonded via the adhesive layer, the columnar crystal region of the scintillator becomes the main light emitting region. In addition, the distance between the main light emitting region and the light detecting unit is shortened, which is desirable because a radiation image with high sharpness can be obtained.

  By the way, the scintillator made of CsI is formed by vapor deposition on a vapor deposition substrate made of Al (aluminum) or the like, and the light detection part is formed on a substrate made of glass or the like, but Al and glass have a large difference in thermal expansion coefficient. (For example, the thermal expansion coefficient of glass is about 30 PPM, whereas the thermal expansion coefficient of glass is about 3 PPM). For this reason, in the configuration in which the scintillator and the light detection unit are bonded together via the adhesive layer as described above, the scintillator and the light detection unit are warped in accordance with the temperature change, and the scintillator and the light detection unit are peeled off. Is applied to the adhesive layer, the adhesive layer deteriorates over time.

  In addition, in the configuration in which the light detection unit and the adhesive layer are arranged on the radiation incident side of the scintillator as described above, since radiation passes through the light detection unit and the adhesive layer, deterioration of the adhesive layer with time also occurs due to the transmission of this radiation. . In addition, for the purpose of reducing the thickness of the radiation detection panel, if a configuration is adopted in which the bonded scintillator and the light detection unit are attached to the inner surface of the top plate of the radiation detection panel housing, the subject is photographed when the radiation image is captured. The weight of the person's body is applied as a load to the top plate of the housing, and this load is also applied to the adhesive layer, which causes deterioration of the adhesive layer over time. When the adhesive layer deteriorates with time as described above, a gap is generated between the adhesive layer and the scintillator or the light detection unit, and this gap appears as an image defect on the radiographic image. There is a problem that it leads to a decrease in diagnosis accuracy in diagnosis.

  On the other hand, the techniques described in Patent Documents 1 and 3 are techniques for improving the adhesive strength of the adhesive layer. When the adhesive strength of the adhesive layer decreases with time, the adhesive layer and the scintillator or light detection No consideration has been given to avoiding a decrease in diagnostic accuracy in diagnosis using a radiographic image due to an image defect appearing on the radiographic image due to a gap generated between the two.

  Further, the technique described in Patent Document 2 predicts the number of defective pixels, the size, and the density increase rate per unit area, and issues a warning when at least one predicted value exceeds a threshold value. Unless a clear increase tendency appears in at least one of the number of defective pixels, the size, and the increase rate of the density per unit area, the predicted value does not exceed the threshold value and no warning is issued. Image defects that appear on the radiographic image due to voids created between the adhesive layer and the scintillator or photodetection unit include defects that have a higher density on the radiographic image than the original density (called black defect areas). , There is a defective part (referred to as a white defect part) whose density on the radiographic image is lower than the original density. Among these, the white defect part is a calcified region in radiography of the breast (also referred to as mammography). There is a risk of being mistaken. For this reason, it is desirable to detect an increase in the probability of an increase in the white defect portion before a clear increase tendency appears in the white defect portion appearing on the radiographic image, but this is realized by the technique described in Patent Document 2. It is difficult.

  The present invention has been made in consideration of the above-mentioned fact, and the white defect portion in the radiographic image increases before the clear increase tendency appears in the white defect portion in the radiographic image as the contact member deteriorates with time. The object is to obtain a radiographic imaging device capable of detecting that the possibility has increased.

  In order to achieve the above object, a radiographic imaging apparatus according to the invention described in claim 1 is a scintillator that has a flat plate shape as a whole, has a columnar crystal structure, and absorbs irradiated radiation to emit light. A flat plate-shaped photodetection unit arranged to face the columnar crystal structure of the scintillator and detecting light emitted from the scintillator as a radiation image, and arranged between the scintillator and the photodetection unit The columnar crystal structure portion of the scintillator is in close contact with the first contact surface, and is closely contacted with the light detection portion and the second contact surface. A contact member in which the contact force of the first contact surface and the contact force of the second contact surface are set so as to proceed in the second contact surface rather than in the contact surface. Has been.

  The invention according to claim 1 is a flat plate having a columnar crystal structure part, and having a columnar crystal structure part that absorbs irradiated radiation and emitting light, and is a flat plate and faces the columnar crystal structure part of the scintillator. And a light detection unit that detects light emitted from the scintillator as a radiation image. Further, a close contact member is disposed between the scintillator and the light detection unit, and the close contact member is in close contact with the columnar crystal structure portion of the scintillator at the first close contact surface and at the light detection unit and the second close contact surface. It is in close contact.

  Here, in the above configuration, the inventors of the present application, when a gap is generated between the columnar crystal structure portion of the scintillator and the close contact member (in the first close contact surface), the white space is white on the radiographic image. It often appears as a defect part, and when a gap is generated between the light detection part and the contact member (in the second contact surface), this gap often appears as a black defect part on the radiation image. I found.

  That is, the gap generated between the columnar crystal structure portion of the scintillator and the close contact member (in the first close contact surface) is easily affected by scratches originally attached to the substrate on which the scintillator is formed. In many cases, the gap is formed in the portion that is formed, and the shape of the gap formed in the first contact surface is also undefined similarly to the scratch originally attached to the substrate. For this reason, as shown in FIG. 1, scattering of light emitted from the scintillator is likely to occur in the gap generated in the first contact surface, and the amount of light incident on the light detection unit is reduced, thereby reducing the gap. Tends to appear as a white defect on a radiographic image. As an example, when the average diameter of the columnar crystals is 10 μm and the size of one pixel is 100 μm, as shown in FIG. The voids generated in (inner) appear as white defects on the radiation image.

  On the other hand, the gap generated between the light detection unit and the close contact member (in the second close contact surface) is often caused by uneven bonding between the light detection unit and the close contact member. Most of the generated voids are circular. For this reason, as shown in FIG. 1, in the gap generated in the second contact surface, the light emitted from the scintillator is likely to be concentrated, and the amount of light incident on the light detection unit increases, thereby increasing the gap. Tends to appear as a black defect on a radiographic image. Note that the size of the gap that appears in the second contact surface and appears as a black defect on the radiation image is approximately the same as the size of the gap that appears in the first contact surface and appears as a white defect on the radiation image. .

  In the invention according to claim 1, focusing on the fact that the gap appearing as a black defect portion on the radiographic image is a gap generated in an adhesion surface different from the gap appearing as a white defect portion on the radiographic image as described above. The adhesion force of the first adhesion surface of the adhesion member and the second adhesion surface so that the generation of voids in the adhesion surface due to deterioration with time proceeds in the second adhesion surface rather than in the first adhesion surface. The adhesion strength of each is set. As a result, the increase of the black defect portion among the white defect portion and the black defect portion appearing in the radiation image progresses with the deterioration of the contact member over time. By detecting the increase in black defect in the image, the white defect in the radiographic image may increase before the clear increase in the white defect in the radiographic image appears as the contact member deteriorates over time. It becomes possible to detect that the performance has increased.

  In the invention described in claim 1, for example, as described in claim 2, the radiation image detected by the light detection unit appears in the radiation image due to the gap generated in the first contact surface. Of the white defect portion and the black defect portion appearing in the radiation image due to the gap generated in the second contact surface, the defect portion detecting means for detecting at least the black defect portion, and the defect portion detecting means detect It is preferable to further include a determination unit that determines whether at least one of the number and area of the black defect portions is equal to or greater than a preset threshold value. Thereby, based on whether or not at least one of the number and area of the detected black defect portions is equal to or greater than the threshold value, a clear increasing tendency appears in the white defect portions in the radiographic image as the contact member deteriorates with time. Prior to this, it is possible to reliably detect that the possibility of an increase in the number of white defect portions in the radiographic image has increased.

  Also, in the invention described in claim 2, for example, as described in claim 3, when the determination means determines that at least one of the number and area of the black defect portions is equal to or greater than a preset threshold value, a notification is given. It is preferable to provide a notification means. As a result, the possibility that the white defect portion in the radiographic image is increased is increased, the user (e.g., before the clear increase tendency appears in the white defect portion in the radiographic image with the deterioration of the contact member over time) Radiologists etc.). Note that the notification by the notification unit may be performed by switching the display state of the display unit that is provided in, for example, the radiographic imaging device and can be switched to a plurality of display states, or predetermined information to an external device such as a console. You may do this by sending.

  Further, in the invention according to claim 2 or claim 3, as described in claim 4, for example, the determination means sets in advance at least one of the number and area of the black defect portions detected by the defect portion detection means. A determination means for determining whether or not at least one of the number and area of black defect portions is equal to or greater than a second threshold value that is greater than the first threshold value. Therefore, it is preferable to provide prohibition processing means for performing an imaging prohibition process for prohibiting radiographic image capturing when it is determined that at least one of the number and area of black defect portions is equal to or greater than the second threshold.

  When at least one of the number and area of the black defect portions exceeds the first threshold value and exceeds the second threshold value, there is a high possibility that the white defect portions in the radiographic image are also increased. It can be determined that there is a high possibility that the diagnosis accuracy is adversely affected when the diagnosis is performed. In the invention according to claim 4, in such a case, the radiographic image is prohibited from being taken, thereby preventing the diagnosis from being performed using the radiographic image that is likely to have an increased white defect portion. be able to. Note that the imaging prohibition process by the prohibition processing unit is also performed, for example, by switching the display state of the display unit that is provided in the radiographic imaging apparatus and can be switched to a plurality of display states to a display state that means imaging prohibition. Alternatively, it may be performed by transmitting predetermined information indicating prohibition of photographing to an external device such as a console.

  Further, in the invention according to any one of claims 2 to 4, so that the generation of voids in the contact surface due to deterioration with time proceeds in the second contact surface rather than in the first contact surface, Although the adhesion force of the first adhesion surface and the adhesion force of the second adhesion surface are respectively set, the progress of the void generation in the first adhesion surface and the progression of the void generation in the second adhesion surface There may be some variation in the relationship. In consideration of this, for example, as described in claim 5, the defect detection unit also detects a white defect part, and the determination unit determines whether at least one of the number and area of the white defect parts detected by the defect detection unit is It is preferable to configure so as to determine whether or not a predetermined threshold value is exceeded. Thereby, even when the generation of voids in the first contact surface progresses relatively early and white defect portions in the radiographic image increase relatively early, this can be reliably detected.

  In addition, the region of interest in diagnosis using a radiographic image is a region in which a radiographic image of a part to be diagnosed is reflected, for example, in mammography, a radiographic image of a breast is reflected in the peripheral portion of the radiographic image, etc. The attention area in the radiographic image differs depending on the part to be diagnosed, the purpose of diagnosis, and the like. In consideration of this, in the invention described in claim 4, for example, as described in claim 6, the defect detection unit detects the black defect part and the white defect part separately, and the determination unit detects the defect part detection unit. Determining whether or not at least one of the number and area of the white defect portions detected by the above is equal to or greater than a preset threshold value for each region when the radiation image is divided into a plurality of regions, and prohibition processing means Is a process for prohibiting radiographic image capturing using a region in which at least one of the number and area of white defect portions is determined to be greater than or equal to a preset threshold value by a determination unit, as a plurality of regions You may comprise so that it may perform.

  Thereby, even if it is a radiographic imaging device in which a white defect part appears comparatively many in a partial area in a radiographic image under the influence of the gap generated in the first contact surface, the partial area is not used ( It is possible to use for radiographic imaging (the partial area is not a target area), and it is possible to effectively use a radiographic imaging apparatus in a state of waiting for maintenance work such as replacement of a contact member. .

  Further, in the invention according to any one of claims 2 to 6, for example, as described in claim 7, a storage unit that stores a determination result by the determination unit, an imaging region and An acquisition means for acquiring imaging condition information representing at least one of diagnostic uses of a radiographic image to be captured, a display means capable of switching to a plurality of types of display states, and an imaging condition information acquired by the acquisition means are stored in a storage means Display control means for determining whether or not the radiographic image is captured under the imaging condition represented by the imaging condition information by collating with the determined determination result, and switching the display state of the display means according to the determination result. May be.

  The appropriateness of radiographic image capture can be determined by a radiographing operator or the like. For example, in an environment where a plurality of radiographic image capturing apparatuses exist, the number and size of defective portions in each radiographic image capturing apparatus. Is not constant, there is a possibility that an error or the like may occur in the determination by the photographing operator or the like. On the other hand, in the invention according to claim 7, the display control means makes the above determination, and the display state of the display means is switched according to the determination result. Therefore, even in an environment where a plurality of radiographic imaging apparatuses exist, the imaging is performed. A radiographic imaging apparatus suitable for radiographic imaging under the imaging conditions indicated by the condition information can be used for imaging without error.

  Further, in the invention according to claim 7, as described in claim 8, for example, among the plurality of display states of the display means, an appropriate orientation of the casing of the radiographic image capturing apparatus at the time of radiographic image capturing The defect state detection means distinguishes and detects the black defect portion and the white defect portion, and the determination means determines the number and area of the white defect portions detected by the defect portion detection means. Whether or not at least one of the radiographic images is equal to or greater than a preset threshold value is determined for each area when the radiation image is divided into a plurality of areas, and the display control means determines that the imaging condition represented by the imaging condition information is When the photographing condition is that the subject is photographed on one end of the radiation irradiation surface of the body, the proper orientation of the housing at the time of radiographic image photographing is determined based on the determination result stored in the storage unit The display status of the display means. May be configured to switch to a display state of indicating proper orientation was.

  As described above, examples of imaging conditions under which the subject is imaged on one end side of the radiation irradiation surface of the housing include breast imaging. Further, the proper orientation of the housing includes an orientation in which a subject is photographed in a region where the number and area of white defect portions are less than a threshold among a plurality of regions. In the invention described in claim 8, when shooting is performed under the above shooting conditions, the proper orientation of the housing is determined, and the display state of the display means is switched to the display state instructing the proper orientation of the housing. When radiographic images are captured under the above-described imaging conditions, it is possible to perform imaging in a state where the casing is oriented in an appropriate direction without error.

  Further, in the invention according to any one of claims 1 to 8, setting the adhesion force of the first adhesion surface and the adhesion force of the second adhesion surface, respectively, for example, as described in claim 9 In addition, a first adhesive layer for closely attaching the adhesion member to the scintillator on one surface of the support is provided, and a second adhesive layer for closely adhering to the light detection unit on the other surface of the support. This can be realized by adjusting the adhesive strength of the first adhesive layer and the second adhesive layer with the provided configuration.

  Further, in the invention according to any one of claims 1 to 9, for example, as described in claim 10, radiation is incident from the light detection unit side of the scintillator and the light detection unit, and the light detection unit is It is preferable that the scintillator is irradiated with the transmitted radiation. In this configuration, compared to the case where radiation is incident from the scintillator side of the scintillator and the light detection unit, a portion closer to the light detection unit in the scintillator becomes a main light emission region, and the amount of light received by the light detection unit increases. Therefore, the radiation detection sensitivity in the radiographic image capturing apparatus can be improved.

  As described above, according to the present invention, in the configuration in which the columnar crystal structure portion of the scintillator and the close contact member are in close contact with each other on the first close contact surface, and the light detection portion and the close contact member are in close contact with each other on the 2nd close contact surface. The adhesion force of the first adhesion surface and the adhesion force of the second adhesion surface are set so that the generation of voids in the adhesion surface due to the occurrence proceeds in the second adhesion surface rather than in the first adhesion surface. Therefore, it is possible to detect that the possibility that the white defect portion in the radiographic image increases is increased before the clear increase tendency appears in the white defect portion in the radiographic image as the contact member deteriorates with time. It has an excellent effect that it becomes possible.

It is explanatory drawing for demonstrating that a defect arises on a radiographic image, when a space | gap arises between a contact | adherence member, a scintillator, and a photon detection part. It is a block diagram which shows the structure of the radiation information system demonstrated by embodiment. It is a side view which shows an example of the arrangement | positioning state of each apparatus in the radiography room of a radiographic imaging system. It is a perspective view which shows a partially broken electronic cassette. It is sectional drawing which showed typically an example of the structure of the radiation detector. It is the schematic which shows typically an example of the crystal structure of a scintillator. It is a block diagram which shows the principal part structure of the electric system of an electronic cassette. It is a block diagram which shows the principal part structure of the electrical system of a console and a radiation generator. It is a flowchart which shows the content of the electronic cassette test | inspection process performed with a console. It is a flowchart which shows the content of the defect inspection process performed with an electronic cassette. (A) is an example of a white defect portion and a black defect portion appearing in a radiographic image, and (B) is an image diagram showing an example of dividing a radiographic image into a plurality of regions. (A) is a diagram showing an example of the relationship between the number of defective portions and the alarm output, and (B) is a diagram showing an example of the relationship between the maximum size of the defective portion and the alarm output. It is a diagram which shows an example of a time-dependent change of the number and size of a white defect part / black defect part at the time of not applying this invention. It is sectional drawing which showed the other example of the structure of the radiation detector typically. (A) is an image figure which shows the other example at the time of dividing | segmenting a radiographic image into several area | region, (B) is a perspective view which shows the other structure of the display part provided in the housing | casing.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. 2 shows a radiation information system 10 (hereinafter, referred to as “RIS10” (RIS: (Radiology Information System)) according to the present embodiment, which is a medical appointment, a diagnostic record, etc. in a radiology department in a hospital. A plurality of terminal devices 12, a RIS server 14, and a radiographic imaging system 18 (console 42) installed in each radiographic room (or operating room) in a hospital. The RIS 10 is connected to an in-hospital network 16 comprising a wired or wireless LAN (Local Area Network), and the RIS 10 is a hospital information system (HIS) provided in the same hospital. A HIS server (not shown) for managing the entire HIS is also connected to the hospital network 16.

  Each terminal device 12 is constituted by a personal computer (PC) or the like, and is operated by a doctor or a radiographer. A doctor or a radiographer inputs / views diagnostic information and facility reservation via the terminal device 12, and a radiographic imaging request (imaging reservation) is also input via the terminal device 12. The RIS server 14 is a computer configured to include a storage unit 14A for storing a RIS database (DB). The RIS database includes patient attribute information (for example, patient name, sex, date of birth, age, Blood type, patient ID, etc.), medical history, consultation history, radiographic imaging history, other information about the patient such as data of radiographic images taken in the past, electronic cassette 32 (described later) of each radiographic imaging system 18 Information related to the information (for example, identification number, model, size, sensitivity, usable imaging part (content of imaging request that can be supported), use start date, number of times of use, etc.) is registered. The RIS server 14 performs processing for managing the entire RIS 10 based on information registered in the RIS database (for example, accepts imaging requests from the terminal devices 12 and manages radiographic imaging schedules in the individual radiographic imaging systems 18). Process).

  Each radiographic imaging system 18 is a system that performs radiographic imaging instructed by the RIS server 14 according to the operation of a doctor or radiographer, and generates a radiation generator 34 that generates radiation to be irradiated to a patient (subject). An electronic cassette 32 having a built-in radiation detector that detects radiation that has passed through the patient, converts it into radiation image data, and outputs it; a cradle 40 that charges a battery 96A (see FIG. 4) built in the electronic cassette 32; Each console 42 is provided for controlling the operation of the device. The electronic cassette 32 is an example of a radiographic image capturing apparatus according to the present invention.

  As shown in FIG. 3, a radiation imaging room 44 in which a radiation source 130 (details will be described later) of the radiation generator 34 is disposed, and a standing table 45 used when performing radiation imaging in a standing position, A stand 46 used when performing radiography at the position, and the front space of the stand 45 is set as the shooting position 48 of the subject when performing radiography at the standing position, The space above the prone position 46 is set as a photographing position 50 of the person to be imaged when performing radiography in the prone position. The stand 45 is provided with a holding unit 150 that holds the electronic cassette 32, and the electronic cassette 32 is held by the holding unit 150 when a radiographic image is taken in the standing position. Further, when taking a radiographic image in the supine position, the electronic cassette 32 is placed on the top plate 152 of the supine stand 46.

  Further, in the radiation imaging room 44, the radiation source 130 is arranged around a horizontal axis (see FIG. 5) in order to enable radiation imaging in a standing position and in a standing position by radiation from a single radiation source 130. 3 is provided, and a support moving mechanism 52 is provided that can be rotated in the direction of arrow A in FIG. It has been. The support moving mechanism 52 includes a drive source that rotates the radiation source 130 around a horizontal axis, a drive source that moves the radiation source 130 in the vertical direction, and a drive source that moves the radiation source 130 in the horizontal direction. If the posture at the time of imaging specified by the imaging condition information is standing, the radiation source 130 is set to the position 54 for standing imaging (the patient whose emitted radiation is located at the imaging position 48). If the posture at the time of photographing designated by the photographing condition information is in the supine position, the radiation source 130 is placed at the position for supine photographing (the emitted radiation is located at the photographing position 50). The patient is moved to the position irradiated from above.

  In addition, the cradle 40 is formed with an accommodating portion 40 </ b> A that can accommodate the electronic cassette 32. The electronic cassette 32 is accommodated in the accommodating portion 40A of the cradle 40 when not in use, and the built-in battery is charged by the cradle 40 in this state. Further, when the radiographic image is taken, it is taken out from the cradle 40 by a radiographer or the like, and is held by the holding unit 150 of the stand 45 if the radiographing posture is in the upright position. It is placed on the top plate 152. It should be noted that the electronic cassette 32 is not limited to being disposed at any of the above two types of positions at the time of imaging, and the electronic cassette 32 has portability, so that it can be arbitrarily placed in the radiation imaging room 44 at the time of imaging. It goes without saying that it can be arranged freely at the position of

  Next, the electronic cassette 32 will be described. As shown in FIG. 4, the electronic cassette 32 includes a rectangular parallelepiped casing 54 made of a material that transmits the radiation X and having a rectangular irradiation surface 56 on which the radiation X is irradiated. When the electronic cassette 32 is used in an operating room or the like, blood or other bacteria may adhere to it. For this reason, the electronic cassette 32 is hermetically sealed by the housing 54 and has a waterproof structure, and the same electronic cassette 32 can be used repeatedly by sterilizing and washing as necessary.

  In the housing 54 of the electronic cassette 32, radiation detection as a light detection unit of the present invention is performed in order from the radiation X irradiation surface 56 side of the housing 54 along the arrival direction of the radiation X that has passed through the subject. And a scintillator 71 as a scintillator of the present invention. In addition, a case 31 that houses various electronic circuits including a microcomputer and a rechargeable and detachable battery 96 </ b> A is disposed inside the housing 54 at one end along the longitudinal direction of the irradiation surface 56. Yes. The radiation detector 60 and the various electronic circuits described above are operated by electric power supplied from a battery 96 </ b> A housed in the case 31. In order to avoid damaging the various electronic circuits housed in the case 31 with the radiation X, a radiation shielding member made of a lead plate or the like is provided on the irradiation surface 56 side of the case 31 in the housing 54. It is arranged.

  Further, the irradiation surface 56 of the housing 54 is composed of a plurality of LEDs, and the operation such as the operation mode of the electronic cassette 32 (for example, “ready state” or “data transmitting”), the remaining capacity state of the battery 96A, and the like. A display unit 56A for displaying the state is provided. The display unit 56A may be composed of a light emitting element other than an LED, or may be composed of display means such as a liquid crystal display or an organic EL display. The display unit 56 </ b> A may be provided at a site other than the irradiation surface 56.

Next, the scintillator 71 will be described. The scintillator 71 irradiates the irradiation surface 56 of the housing 54 that has passed through the body of the subject, and absorbs the radiation X irradiated through the top plate of the housing 54 and the radiation detector (TFT substrate) 60. Emit light. In general, as the scintillator, for example, a material such as CsI: Tl (cesium iodide added with thallium)), CsI: Na (sodium-activated cesium iodide), GOS (Gd ₂ O ₂ S: Tb), or the like may be used. it can.

  However, in this embodiment, as shown in FIG. 6 as an example, the scintillator 71 is formed with a columnar crystal region composed of columnar crystals 71A on the radiation incident / light emission side (radiation detector 60), and the radiation incident on the scintillator 71 A non-columnar crystal region composed of a non-columnar crystal 71B is formed on the opposite side, and a material containing CsI is used as the scintillator 71, and the material is vapor-deposited on the vapor deposition substrate 75. A scintillator 71 in which columnar crystal regions are formed is obtained. The vapor deposition substrate 75 is preferably made of a material having high heat resistance, and aluminum is preferable from the viewpoint of low cost. In the scintillator 71 according to this embodiment, the average diameter of the columnar crystals 71A is approximately uniform along the longitudinal direction of the columnar crystals 71A.

  As described above, the scintillator 71 has a structure in which a columnar crystal region and a non-columnar crystal region are formed, and a columnar crystal region composed of the columnar crystal 71A from which high-efficiency light emission is obtained is disposed on the radiation detector 60 side. Thus, the light generated by the scintillator 71 travels through the columnar crystal 71A and is emitted to the radiation detector 60, and the diffusion of the light emitted to the radiation detector 60 side is suppressed, so that it is detected by the electronic cassette 32. The blur of the radiation image is suppressed. Further, the light that reaches the deep part (non-columnar crystal region) of the scintillator 71 is also reflected by the non-columnar crystal 71B toward the radiation detector 60, so that the amount of light incident on the radiation detector 60 (in the scintillator 71). The detection efficiency of the emitted light is improved.

When the thickness of the columnar crystal region located on the radiation incident side of the scintillator 71 is t1, and the thickness of the non-columnar crystal region located on the vapor deposition substrate 75 side of the scintillator 71 is t2, t1 and t2 have the following relationship: It is preferable to satisfy the formula.
0.01 ≦ (t2 / t1) ≦ 0.25

  When the thickness t1 of the columnar crystal region and the thickness t2 of the non-columnar crystal region satisfy the above relational expression, a region that has high luminous efficiency and prevents light diffusion (columnar crystal region), and a region that reflects light (noncolumnar) The ratio of the scintillator 71 along the thickness direction of the scintillator 71 becomes a suitable range, and the light emission efficiency of the scintillator 71, the detection efficiency of the light emitted by the scintillator 71, and the resolution of the radiation image are improved. If the thickness t2 of the non-columnar crystal region is too thick, the region with low light emission efficiency increases and the sensitivity of the electronic cassette 32 is lowered. Therefore, (t2 / t1) is more preferably in the range of 0.02 or more and 0.1 or less. .

  In the above description, the scintillator 71 having a structure in which the columnar crystal region and the non-columnar crystal region are continuously formed has been described. For example, instead of the non-columnar crystal region, a light reflection layer made of aluminum or the like is provided, and the columnar crystal region is formed. Only a crystal region may be formed, or another structure may be used.

  Next, the radiation detector 60 will be described. The radiation detector 60 detects light emitted from the light emission side of the scintillator 71. As shown in FIG. 5, a photoelectric conversion unit 72 composed of a photodiode (PD: PhotoDiode) and the like, a thin film transistor (TFT: As shown in FIG. 5, a plurality of pixel portions 74 each having a thin film transistor 70 and a storage capacitor 68 are formed in a matrix on an insulating substrate 64 having a flat plate shape and a rectangular outer shape in plan view. TFT active matrix substrate (hereinafter referred to as “TFT substrate”).

  In this embodiment, the radiation detector (TFT substrate) 60 is disposed on the radiation irradiation surface side of the scintillator 71. However, the scintillator and the light detection detector (radiation detector 60) are disposed in such a positional relationship. This method is called “surface reading method (ISS: Irradiation Side Sampling)” (configuration corresponding to the invention of claim 10). Since the scintillator emits light more strongly on the radiation incident side, the surface reading method (ISS) in which the light detector (radiation detector) is arranged on the radiation incident side of the scintillator is the light detector (radiation) on the side opposite to the radiation incident side of the scintillator. Since the light detection unit and the light emission position of the scintillator are closer than the “PSS (Penetration Side Sampling)” where the detector is placed, the resolution of the radiographic image obtained by imaging is high, and the light detection unit Increasing the amount of light received by the (radiation detector) results in an improvement in the sensitivity of the radiographic imaging device (electronic cassette).

The photoelectric conversion unit 72 is configured such that a photoelectric conversion film 72C that absorbs light emitted from the scintillator 71 and generates charges according to the absorbed light is disposed between the lower electrode 72A and the upper electrode 72B. Yes. The lower electrode 72A is preferably made of a conductive material that is transparent at least with respect to the emission wavelength of the scintillator 71, since the light emitted from the scintillator 71 needs to enter the photoelectric conversion film 72C. It is preferable to use a transparent conductive oxide (TCO) that has a high transmittance for visible light and a small resistance value. Although a metal thin film such as Au can be used as the lower electrode 72A, the TCO is preferable because it tends to increase the resistance value when an optical transmittance of 90% or more is obtained. For example, ITO, IZO, AZO, FTO, SnO ₂ , TiO ₂ , ZnO ₂ or the like is preferably used, and ITO is most preferable from the viewpoint of process simplicity, low resistance, and transparency. The lower electrode 72A may have a single configuration common to all the pixel portions, or may be divided for each pixel portion.

  The photoelectric conversion film 72C absorbs the light emitted from the scintillator 71 and generates a charge corresponding to the absorbed light. The material constituting the photoelectric conversion film 72 </ b> C may be any material that absorbs light and generates charges, and for example, amorphous silicon, an organic photoelectric conversion material, or the like can be used. When the photoelectric conversion film 72 </ b> C is made of amorphous silicon, the light emitted from the scintillator 71 can be configured to absorb over a wide wavelength range. However, it is necessary to perform vapor deposition for forming the photoelectric conversion film 72C made of amorphous silicon. If the insulating substrate 64 is made of a synthetic resin, the heat resistance of the insulating substrate 64 may be insufficient.

  On the other hand, when the photoelectric conversion film 72C is made of a material containing an organic photoelectric conversion material, an absorption spectrum showing high absorption mainly in the visible light region is obtained, and light other than light emitted from the scintillator 71 by the photoelectric conversion film 72C is obtained. Since almost no electromagnetic wave is absorbed, it is possible to suppress noise generated when radiation such as X-rays and γ-rays is absorbed by the photoelectric conversion film 72C. In addition, the photoelectric conversion film 72C made of an organic photoelectric conversion material can be formed by attaching an organic photoelectric conversion material on a body to be formed using a droplet discharge head such as an inkjet head. Heat resistance is not required. For this reason, in this embodiment, the photoelectric conversion film 72C of the photoelectric conversion unit 72 is formed of an organic photoelectric conversion material.

  When the photoelectric conversion film 72C is made of an organic photoelectric conversion material, radiation is hardly absorbed by the photoelectric conversion film 72C. Therefore, in the surface reading method (ISS) in which the radiation detector 60 is disposed so that the radiation is transmitted, radiation detection is performed. Attenuation of radiation due to transmission through the vessel 60 can be suppressed, and a decrease in sensitivity to radiation can be suppressed. Therefore, it is particularly suitable for the surface reading method (ISS) to configure the photoelectric conversion film 72C with an organic photoelectric conversion material.

  The organic photoelectric conversion material constituting the photoelectric conversion film 72 </ b> C preferably has an absorption peak wavelength that is closer to the emission peak wavelength of the scintillator 71 in order to absorb light emitted from the scintillator 71 most efficiently. Ideally, the absorption peak wavelength of the organic photoelectric conversion material coincides with the emission peak wavelength of the scintillator 71, but if the difference between the two is small, the light emitted from the scintillator 71 can be sufficiently absorbed. . Specifically, the difference between the absorption peak wavelength of the organic photoelectric conversion material and the emission peak wavelength with respect to the radiation of the scintillator 71 is preferably within 10 nm, and more preferably within 5 nm.

  Examples of organic photoelectric conversion materials that can satisfy such conditions include quinacridone-based organic compounds and phthalocyanine-based organic compounds. For example, since the absorption peak wavelength in the visible region of quinacridone is 560 nm, if quinacridone is used as the organic photoelectric conversion material and CsI (Tl) is used as the material of the scintillator 71, the difference in peak wavelength can be made within 5 nm. Thus, the amount of charge generated in the photoelectric conversion film 72C can be substantially maximized.

  The photoelectric conversion film 72C applicable to the radiation image capturing apparatus will be specifically described. The electromagnetic wave absorption / photoelectric conversion site in the radiographic imaging apparatus is an organic layer including electrodes 72A and 72B and a photoelectric conversion film 72C sandwiched between the electrodes 72A and 72B. More specifically, this organic layer is a part that absorbs electromagnetic waves, a photoelectric conversion part, an electron transport part, a hole transport part, an electron blocking part, a hole blocking part, a crystallization preventing part, an electrode, and an interlayer contact. It can be formed by stacking or mixing improved parts.

  The organic layer preferably contains an organic p-type compound or an organic n-type compound. An organic p-type semiconductor (compound) is a donor organic semiconductor (compound) mainly represented by a hole transporting organic compound, and is an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Accordingly, any organic compound having an electron donating property can be used as the donor organic compound. The organic n-type semiconductor (compound) is an acceptor organic semiconductor (compound) mainly represented by an electron transporting organic compound, and is an organic compound having a property of easily accepting electrons. More specifically, the organic compound having the higher electron affinity when two organic compounds are used in contact with each other. Therefore, any organic compound can be used as the acceptor organic compound as long as it is an organic compound having an electron accepting property.

  Since the materials applicable as the organic p-type semiconductor and the organic n-type semiconductor and the configuration of the photoelectric conversion film 72C are described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

  In addition, the photoelectric conversion unit 72 only needs to include at least the electrode pairs 72A and 72B and the photoelectric conversion film 72C, but in order to suppress an increase in dark current, at least one of an electron blocking film and a hole blocking film is provided. It is preferable to provide both.

  The electron blocking film can be provided between the upper electrode 72B and the photoelectric conversion film 72C. When a bias voltage is applied between the upper electrode 72B and the lower electrode 72A, the electron blocking film is applied from the upper electrode 72B to the photoelectric conversion film 72C. An increase in dark current due to injection of electrons can be suppressed. An electron donating organic material can be used for the electron blocking film. The material actually used for the electron blocking film may be selected according to the material of the adjacent electrode and the material of the adjacent photoelectric conversion film 72C, and the electron affinity is 1.3 eV or more from the work function (Wf) of the adjacent electrode material. A material having a large (Ea) and an Ip equivalent to or smaller than the ionization potential (Ip) of the material of the adjacent photoelectric conversion film 72C is preferable. Since the material applicable as the electron donating organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

  The thickness of the electron blocking film is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, and particularly preferably, in order to reliably exhibit the dark current suppressing effect and prevent a decrease in photoelectric conversion efficiency of the photoelectric conversion unit 72. It is 50 nm or more and 100 nm or less.

  The hole blocking film can be provided between the photoelectric conversion film 72C and the lower electrode 72A, and when a bias voltage is applied between the upper electrode 72B and the lower electrode 72A, the lower electrode 72A to the photoelectric conversion film 72C. It is possible to suppress the increase of dark current due to injection of holes into the substrate. An electron-accepting organic material can be used for the hole blocking film. The material actually used for the hole blocking film may be selected in accordance with the material of the adjacent electrode and the material of the adjacent photoelectric conversion film 72C, and the ionization is 1.3 eV or more from the work function (Wf) of the adjacent electrode material. It is preferable that the potential (Ip) is large and that the Ea is equal to or larger than the electron affinity (Ea) of the material of the adjacent photoelectric conversion film 72C. Since the material applicable as the electron-accepting organic material is described in detail in Japanese Patent Application Laid-Open No. 2009-32854, description thereof is omitted.

  The thickness of the hole blocking film is preferably 10 nm or more and 200 nm or less, more preferably 30 nm or more and 150 nm or less, particularly preferably, in order to surely exhibit the dark current suppressing effect and prevent a decrease in the photoelectric conversion efficiency of the photoelectric conversion unit 72. Is from 50 nm to 100 nm.

  When the bias voltage is set so that holes move to the lower electrode 72A and electrons move to the upper electrode 72B among the charges generated in the photoelectric conversion film 72C, the electron blocking film and the hole blocking film are used. It is sufficient to reverse the position of. Moreover, it is not essential to provide both the electron blocking film and the hole blocking film, and if any of them is provided, a certain degree of dark current suppressing effect can be obtained.

  In the TFT 70, a gate electrode, a gate insulating film, and an active layer (channel layer) are stacked, and a source electrode and a drain electrode are formed on the active layer at a predetermined interval. The active layer can be formed of any one of, for example, amorphous silicon, amorphous oxide, organic semiconductor material, carbon nanotube, etc., but the material capable of forming the active layer is not limited to these. .

As an amorphous oxide capable of forming an active layer, for example, an oxide containing at least one of In, Ga, and Zn (for example, an In-O system) is preferable, and at least one of In, Ga, and Zn is used. Oxides containing two (eg, In—Zn—O, In—Ga—O, and Ga—Zn—O) are more preferable, and oxides including In, Ga, and Zn are particularly preferable. As the In—Ga—Zn—O-based amorphous oxide, an amorphous oxide whose composition in a crystalline state is represented by InGaO ₃ (ZnO) _m (m is a natural number less than 6) is preferable, and InGaZnO is particularly preferable. ₄ is more preferable. Note that the amorphous oxide capable of forming the active layer is not limited to these.

  Examples of the organic semiconductor material capable of forming an active layer include, but are not limited to, phthalocyanine compounds, pentacene, vanadyl phthalocyanine, and the like. In addition, about the structure of a phthalocyanine compound, since it demonstrates in detail by Unexamined-Japanese-Patent No. 2009-212389, description is abbreviate | omitted.

  If the active layer of the TFT 70 is formed of any one of an amorphous oxide, an organic semiconductor material, a carbon nanotube, etc., the radiation such as X-rays is not absorbed, or even if it is absorbed, the amount remains very small. Generation of noise in the output unit 104 can be effectively suppressed.

  Further, when the active layer is formed of carbon nanotubes, the switching speed of the TFT 70 can be increased, and the degree of light absorption in the visible light region of the TFT 70 can be reduced. In addition, when the active layer is formed of carbon nanotubes, the performance of the TFT 70 is remarkably deteriorated just by mixing a very small amount of metallic impurities into the active layer. Therefore, it must be used for forming the active layer.

  In addition, since the film | membrane formed with the organic photoelectric conversion material and the film | membrane formed with the organic-semiconductor material have sufficient flexibility, the photoelectric conversion film 72C formed with the organic photoelectric conversion material, and an active layer are made into organic. If the TFT 70 made of a semiconductor material is combined, it is not always necessary to increase the rigidity of the radiation detector 60 in which the weight of the patient's body is added as a load.

  Further, the insulating substrate 64 may be any substrate as long as it has optical transparency and little radiation absorption. Here, both the amorphous oxide constituting the active layer of the TFT 70 and the organic photoelectric conversion material constituting the photoelectric conversion film 72C of the photoelectric conversion portion 72 can be formed at a low temperature. Therefore, the insulating substrate 64 is not limited to a substrate having high heat resistance such as a semiconductor substrate, a quartz substrate, and a glass substrate, and a flexible substrate made of synthetic resin, aramid, or bionanofiber can also be used. Specifically, flexible materials such as polyesters such as polyethylene terephthalate, polybutylene phthalate, polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), etc. A conductive substrate can be used. By using such a flexible substrate made of synthetic resin, it is possible to reduce the weight, which is advantageous for carrying around, for example. The insulating substrate 64 includes an insulating layer for ensuring insulation, a gas barrier layer for preventing permeation of moisture and oxygen, an undercoat layer for improving flatness or adhesion to electrodes, and the like. May be provided.

  Since aramid can be applied at a high temperature process of 200 ° C. or more, the transparent electrode material can be cured at a high temperature to reduce the resistance, and can be applied to automatic mounting of a driver IC including a solder reflow process. Moreover, since aramid has a thermal expansion coefficient close to that of ITO (indium tin oxide) or a glass substrate, there is little warping after manufacturing and it is difficult to break. In addition, aramid can make a substrate thinner than a glass substrate or the like. Note that the insulating substrate 64 may be formed by stacking an ultrathin glass substrate and aramid.

  The bionanofiber is a composite of a cellulose microfibril bundle (bacterial cellulose) produced by bacteria (Acetobacter Xylinum) and a transparent resin. The cellulose microfibril bundle has a width of 50 nm and a size of 1/10 of the visible light wavelength, and has high strength, high elasticity, and low thermal expansion. By impregnating and curing a transparent resin such as an acrylic resin or an epoxy resin in bacterial cellulose, a bio-nanofiber having a light transmittance of about 90% at a wavelength of 500 nm can be obtained while containing 60 to 70% of the fiber. Bionanofiber has a low coefficient of thermal expansion (3-7ppm) comparable to silicon crystals, and is as strong as steel (460MPa), highly elastic (30GPa), and flexible, compared to glass substrates, etc. The insulating substrate 64 can be thinned.

  When a glass substrate is used as the insulating substrate 64, the thickness of the radiation detector (TFT substrate) 60 as a whole is about 0.7 mm, for example, but in this embodiment, considering the reduction in thickness of the electronic cassette 32, the insulating property is reduced. As the substrate 64, a thin substrate made of a light-transmitting synthetic resin is used. Thereby, the thickness of the radiation detector (TFT substrate) 60 as a whole can be reduced to about 0.1 mm, for example, and the radiation detector (TFT substrate) 60 can be made flexible. Further, by providing flexibility to the radiation detector (TFT substrate) 60, the impact resistance of the electronic cassette 32 is improved, and even when an impact is applied to the electronic cassette 32, it is difficult to be damaged. In addition, plastic resin, aramid, bio-nanofiber, etc. all absorb little radiation, and when the insulating substrate 64 is formed of these materials, the amount of radiation absorbed by the insulating substrate 64 is also reduced. Even if the radiation is transmitted through the radiation detector 60 by (ISS), a decrease in sensitivity to radiation can be suppressed.

  It is not essential to use a synthetic resin substrate as the insulating substrate 64 of the electronic cassette 32. Although the thickness of the electronic cassette 32 increases, a substrate made of another material such as a glass substrate is used as the insulating substrate 64. You may make it use as.

  A close contact member 146 is provided between the scintillator 71 and the radiation detector 60. The contact member 146 includes a film-like support 146A, and an adhesive layer 146B is formed on one surface of the support 146A, and an adhesive layer 146C is formed on the opposite surface of the support 146A. As shown in FIG. 6, the adhesive layer 146 </ b> B of the close contact member 146 is in close contact with the tip of the columnar crystal 71 </ b> A of the scintillator 71 over the entire surface of the scintillator 71, and the adhesive layer 146 </ b> C of the close contact member 146 is the radiation detector 60. Are in close contact with the surface of the radiation detector 60.

  Here, the contact member 146 gradually deteriorates with time due to stress applied in accordance with a temperature change or radiation transmitted through the contact member 146, and the adhesive force of the adhesive layers 146B and 146C gradually decreases. Further, if the back surface of the radiation detector 60 (the surface opposite to the surface to which the adhesive layer 146C is in close contact) is attached to the inner surface of the top plate of the housing 54, the radiation image is captured every time. Due to the load applied to the contact member 146, the deterioration of the contact member 146 further proceeds. In addition, when a void is generated in the adhesion surface (an example of the first adhesion surface of the present invention) between the adhesion layer 146B and the scintillator 71 as the adhesion force of the adhesion layer 146B decreases, the void is photographed radiation. A white defect portion (see also FIG. 11A) appears on the image, and the adhesion surface between the adhesion layer 146C and the radiation detector 60 (second adhesion surface of the present invention) as the adhesion force of the adhesion layer 146C decreases. In the example of FIG. 11A, the void appears as a black defect portion (see also FIG. 11A) on the radiographic image taken. Of the white defect portion and the black defect portion, particularly, the white defect portion adversely affects the accuracy of diagnosis using a radiographic image.

  For this reason, according to the present embodiment, as the adhesion member 146 deteriorates with time, the gap in the adhesion surface between the adhesion layer 146C and the radiation detector 60 is more than the generation of the gap in the adhesion surface between the adhesion layer 146B and the scintillator 71. As shown in FIG. 12 as an example, the number of defective portions and the increase in the maximum size due to the deterioration of the contact member 146 with time are more advanced in the black defect portion than in the white defect portion. Thus, the adhesive strength of the adhesive layers 146B and 146C is set.

  More specifically, the adhesive layer 146B is in close contact with the tip of the columnar crystal 71A of the scintillator 71, and the adhesive force of the adhesive layer 146B acts on the surface of the scintillator 71 corresponding to the gap between the adjacent columnar crystals 71A. Therefore, even when the adhesive strengths of the adhesive layers 146B and 146C are equal, the adhesion surface between the adhesive layer 146B and the scintillator 71 generates more voids than the adhesive surface between the adhesive layer 146C and the radiation detector 60. . For this reason, in this embodiment, the adhesive force of the adhesive layers 146B and 146C is set so that the adhesive force between the adhesive layer 146B and the scintillator 71 is larger than the adhesive force between the adhesive layer 146C and the radiation detector 60. Yes.

  Specifically, as the adhesion member 146, for example, a double-sided tape having different adhesive strengths on the front and back surfaces (for example, 4591HL manufactured by Sumitomo 3M Co., Ltd. (strong adhesion surface = 4.3 N / cm, weak adhesion surface = 0.2 N). / Cm)) may be used, the adhesive layer 146C may be a weak adhesive (for example, an adhesive used in 4591HL manufactured by Sumitomo 3M Co., Ltd.), and the adhesive layer 146B may be a strong adhesive (For example, an adhesive used in a double-sided tape No. 5605 manufactured by Nitto Denko Corporation) may be used. In addition, the same kind of adhesive is used as the adhesive layers 146B and 146C, and a surface treatment (for example, atmospheric pressure plasma treatment or application of a silane coupling agent) is applied to one of the adhesive layers 146B and 146C. May be. In consideration of rework such as replacement of the close contact member 146, an adhesive (such as a UV irradiation disassembly type adhesive) that can be peeled off when necessary may be used as the adhesive layer 146C. In this case, when exchanging the close contact member 146 or the like, after irradiating UV to separate the close contact member 146 and the radiation detector 60 and exchanging the close contact member 146, the close contact member 146 and the radiation detection are performed. It is possible to easily realize the close contact with the container 60 again. The contact member 146 described above is an example of the contact member according to claim 1, more specifically, claim 9.

  Further, as shown in FIG. 7, the radiation detector (TFT substrate) 60 includes a plurality of gate wirings 76 extending in a certain direction (row direction) for turning on / off individual TFTs 70, and the certain constants. The charge accumulated in the storage capacitor 68 (and between the upper electrode 72A and the lower electrode 72B of the photoelectric conversion unit 72) extending along the direction (column direction) intersecting with the direction is read through the on-state TFT 70. For this purpose, a plurality of data wirings 78 are provided. Further, as shown in FIG. 5, a planarizing layer 67 for flattening the TFT substrate is formed at the end of the radiation detector (TFT substrate) 60 opposite to the radiation arrival direction. .

  As shown in FIG. 7, each gate line 76 of the radiation detector 60 is connected to a gate line driver 81, and each data line 78 is connected to a signal processing unit 83. When radiation that has passed through the subject (radiation carrying the image information of the subject) is irradiated onto the electronic cassette 32, the radiation corresponding to each position on the irradiation surface 56 in the scintillator 71 is irradiated with the radiation at each position. The amount of light corresponding to the amount is emitted, and the photoelectric conversion unit 72 of each pixel unit 74 generates a charge having a magnitude corresponding to the amount of light emitted from the corresponding portion of the scintillator 71. Charges are accumulated in the storage capacitors 68 of the individual pixel portions 74 (and between the upper electrode 72A and the lower electrode 72B of the photoelectric conversion portion 72).

  When charges are accumulated in the storage capacitors 68 of the individual pixel portions 74 as described above, the TFTs 70 of the individual pixel portions 74 are supplied in units of rows by signals supplied from the gate line drivers 81 via the gate wirings 76. The charges stored in the storage capacitor 68 of the pixel unit 74 that is sequentially turned on and the TFT 70 is turned on are transmitted through the data wiring 78 as an analog electric signal and input to the signal processing unit 83. Accordingly, the charges accumulated in the storage capacitors 68 of the individual pixel portions 74 are sequentially read out in units of rows.

  The signal processing unit 83 includes an amplifier and a sample hold circuit provided for each data wiring 78, and an electric signal transmitted through each data wiring 78 is amplified by the amplifier and then held in the sample hold circuit. The In addition, a multiplexer and an A / D (analog / digital) converter are connected in order to the output side of the sample and hold circuit, and the electrical signals held in the individual sample and hold circuits are sequentially (serially) input to the multiplexer. The digital image data is converted by an A / D converter.

  An image memory 90 is connected to the signal processing unit 83, and image data output from the A / D converter of the signal processing unit 83 is sequentially stored in the image memory 90. The image memory 90 has a storage capacity capable of storing image data for a plurality of frames, and image data obtained by imaging is sequentially stored in the image memory 90 every time a radiographic image is captured.

  The image memory 90 is connected to a cassette control unit 92 that controls the operation of the entire electronic cassette 32. The cassette control unit 92 includes a microcomputer, and includes a CPU 92A, a memory 92B including a ROM and a RAM, a nonvolatile storage unit 92C including an HDD (Hard Disk Drive), a flash memory, and the like.

  A wireless communication unit 94 is connected to the cassette control unit 92. The wireless communication unit 94 corresponds to a wireless local area network (LAN) standard represented by IEEE (Institute of Electrical and Electronics Engineers) 802.11a / b / g / n, etc. Control the transmission of various information between them. The cassette control unit 92 can wirelessly communicate with the console 42 via the wireless communication unit 94, and can transmit and receive various information to and from the console 42.

  In addition, the electronic cassette 32 is provided with a power supply unit 96, and the various electronic circuits described above (gate line driver 81, signal processing unit 83, image memory 90, wireless communication unit 94, cassette control unit 92, signal detection unit 162). Etc.) are connected to the power supply unit 96 (not shown), and are operated by the power supplied from the power supply unit 96. The power supply unit 96 incorporates the aforementioned battery (secondary battery) 96A so as not to impair the portability of the electronic cassette 32, and supplies power from the charged battery 96A to various electronic circuits.

  As shown in FIG. 8, the console 42 is composed of a computer, a CPU 104 that controls the operation of the entire apparatus, a ROM 106 that stores various programs including a control program in advance, a RAM 108 that temporarily stores various data, and various data Are connected to each other via a bus. In addition, a communication I / F unit 132 and a wireless communication unit 118 are connected to the bus, a display 110 is connected via a display driver 112, and an operation panel 102 is further connected via an operation input detection unit 114. .

  The communication I / F unit 132 is connected to the radiation generator 34 via the connection terminal 42 </ b> A and the communication cable 35. The console 42 (the CPU 104 thereof) transmits / receives various information such as an exposure condition to / from the radiation generator 34 via the communication I / F unit 132. The wireless communication unit 118 has a function of performing wireless communication with the wireless communication unit 94 of the electronic cassette 32, and the console 42 (the CPU 104) transmits and receives various information such as image data to and from the electronic cassette 32. 118. Further, the display driver 112 generates and outputs signals for displaying various information on the display 110, and the console 42 (CPU 104 of the console 42) displays an operation menu, a captured radiation image, and the like on the display 110 via the display driver 112. Display. The operation panel 102 includes a plurality of keys, and various information and operation instructions are input. The operation input detection unit 114 detects an operation on the operation panel 102 and notifies the CPU 104 of the detection result.

  The radiation generator 34 also includes a communication I / F unit 132 that transmits and receives various types of information such as an exposure condition between the radiation source 130 and the console 42, and an exposure condition (this exposure) received from the console 42. And a radiation source controller 134 for controlling the radiation source 130 based on the conditions (including the tube voltage and tube current information).

  Next, the operation of this embodiment will be described. In the radiographic imaging system 18, in order to confirm whether or not each electronic cassette 32 equipped in the radiographic imaging system 18 is usable, the electronic cassette shown in FIG. The inspection process is periodically performed by the console 42 (for example, every day, every week, every month, etc.). The electronic cassette inspection process is performed in units of individual electronic cassettes 32 at the time of starting and closing time.

  That is, in the electronic cassette inspection process, first, in step 300, the radiation source 130 is moved to a preset electron source position for electronic cassette inspection (for example, the position for supine imaging shown in FIG. 3). In the next step 302, a predetermined message is displayed on the display 110, etc., and an instructor such as a radiographer is instructed to set a cassette position for electronic cassette inspection (for example, the position of the prone table 46 shown in FIG. 3). The electronic cassette 32 is instructed to be placed at a position on the top plate 152. In the next step 304, it is determined whether or not the placement of the electronic cassette 32 at the cassette position for electronic cassette inspection is completed, and step 304 is repeated until the determination is affirmative.

  The inspection instructor performs an operation of inputting information indicating completion of arrangement via the operation panel 102 after arranging the electronic cassette 32 at the cassette position for electronic cassette inspection in accordance with the instruction in step 304. As a result, the determination in step 304 is affirmed, the process proceeds to step 306, and a predetermined signal is transmitted to the electronic cassette 32 via the wireless communication unit 118, thereby instructing the electronic cassette 32 to execute defect inspection processing. To do. As a result, a defect inspection process (details will be described later) is performed in the cassette control unit 92 of the electronic cassette 32.

  In step 308, an instruction signal for instructing exposure is transmitted to the radiation generator 34 after transmitting exposure conditions (tube voltage and tube current values) for electronic cassette inspection that have been set in advance. Thereby, the radiation generator 34 emits radiation from the radiation source 130 at a tube voltage and a tube current corresponding to the exposure conditions received in advance from the console 42. The inspection of the electronic cassette 32 in the present embodiment is performed in a state where no subject (object that absorbs radiation) exists between the radiation source 130 and the electronic cassette 32. The exposure conditions for the electronic cassette inspection are as follows: In the individual pixel portions 74 of the radiation detector 60 of the electronic cassette 32 irradiated with radiation in the above-described state, a pixel portion 74 whose output is saturated or a pixel portion 74 whose output is excessively small is not generated. The tube voltage and tube current values are defined.

  In step 310, it is determined whether the result of the defect inspection process performed in the electronic cassette 32 has been received from the electronic cassette 32, and step 310 is repeated until the determination is affirmed. When the result of the defect inspection process is received from the electronic cassette 32, the determination in step 310 is affirmed and the process proceeds to step 312, and the result of the defect inspection process received from the electronic cassette 32 (details will be described later) is displayed on the display 110. The electronic cassette inspection process is terminated.

  Next, a defect inspection process performed by the cassette control unit 92 of the electronic cassette 32 according to an instruction from the console 42 will be described with reference to FIG. In step 320, it is determined whether or not the exposure (radiation irradiation) by the radiation generator 34 has been completed, and step 320 is repeated until the determination is affirmative. Note that the determination in step 320 can be made by, for example, determining whether a certain time has elapsed. In addition, a column of pixel units 74 (a column of pixel units 74 connected to the same gate wiring 76) located on one end side of the irradiation surface 56 in the radiation detector 60 is used for radiation detection. It is also possible to make the determination in step 320 by repeatedly reading out the radiation detection results from the 74 rows and detecting the end of radiation irradiation. Further, instead of the row of the pixel units 74, a sensor unit 206 of the radiation detection unit 200 described later may be used for radiation detection.

  When the determination in step 320 is affirmed, the process proceeds to step 322, and the charges accumulated in all the pixel units 74 of the radiation detector 60 are read and read by the gate line driver 81 and the signal processing unit 83. The image signal is converted into digital image data (radiation image data) representing the density (radiation dose) for each pixel and stored in the image memory 90. In step 324, single pixel data is extracted from the radiation image data stored in the image memory 90 as a processing target. In the next step 326, the density D of the processing target pixel represented by the data extracted in step 324 is set in advance. It is determined whether or not the threshold value Dw is less than the set white defective pixel determination threshold. If the determination in step 326 is negative, the process proceeds to step 328, and whether or not the density D of the pixel to be processed represented by the data extracted in step 324 is greater than or equal to a predetermined threshold value Db for black defective pixel determination. judge.

  If the determination in step 328 is also negative, the process proceeds to step 334. If the determination in step 326 is affirmed, the process proceeds to step 330, the processing target pixel from which data is extracted in step 324 is set as a white defective pixel, and the process proceeds to step 334. If the determination in step 328 is affirmed, the process proceeds to step 332, the processing target pixel from which data is extracted in step 324 is set as a black defective pixel, and the process proceeds to step 334. In step 334, it is determined whether data of all pixels of the radiographic image has been extracted. If the determination is negative, the process returns to step 324, and steps 324 to 334 are repeated until the determination of step 334 is affirmed.

  If the determination in step 334 is affirmed, the process proceeds to step 336, and is there any adjacent pixel on the radiographic image among the pixels set as white defective pixels in step 324 to step 334 described above? Whether or not is detected, white defect pixels adjacent on the radiographic image are integrated into a single white defect portion. Thereby, all the white defect parts in a radiographic image are detected. In the next step 338, it is searched whether there is an adjacent pixel on the radiographic image among the pixels set as the black defective pixel in step 324 to step 334, and it is adjacent on the radiographic image. Integrate black defect pixels into a single black defect. Thereby, all the black defect parts in a radiographic image are detected. Steps 324 to 338 described above are an example of processing performed by the defective portion detection means described in claims 2, 5, and 6.

  In step 340, the total number Nb of black defect portions detected in step 338 and the maximum size Sb of black defect portions are calculated. In step 342, it is determined whether or not the total number Nb of black defect portions calculated in step 340 is equal to or greater than a threshold value Nbth for the number of black defect portions. When this determination is negative, the process proceeds to step 346, information indicating “usable” is provisionally set as the inspection result of the electronic cassette 32, and the process proceeds to step 350. If the determination in step 342 is affirmative, the process proceeds to step 344, where the total number Nb of black defective portions is equal to or greater than the allowable maximum value Nbmax for the number of black defective portions (where allowable maximum value Nbmax> threshold Nbth). To determine. If this determination is negative, the process proceeds to step 348, information indicating “use caution” is provisionally set as the inspection result of the electronic cassette 32, and the process proceeds to step 350.

  In step 350, it is determined whether or not the maximum size Sb of the black defect portion calculated in step 340 is greater than or equal to a threshold value Sbth for the maximum size of the black defect portion. If the determination in step 350 is made, the total number Nb of black defect portions is less than the allowable maximum value Nbmax. Therefore, if the determination in step 350 is negative, the inspection result of the electronic cassette 32 is not changed and the process proceeds to step 356. Transition. If the determination in step 350 is affirmative, the process proceeds to step 352, where the maximum size Sb of the black defect portion is equal to or greater than the allowable maximum value Sbmax for the maximum size of the black defect portion (provided that the allowable maximum value Sbmax> threshold value). Sbth). When this determination is negative, the process proceeds to step 354, information indicating “use caution” is set as the inspection result of the electronic cassette 32, and the process proceeds to step 356. If the determination in step 344 or step 352 is affirmed, the process proceeds to step 358, information indicating “use prohibited” is set as the inspection result of the electronic cassette 32, and the inspection result is displayed in the console 42 in step 368. To complete the defect inspection process.

  The above process will be further described. For example, when the adhesive strengths of the adhesive layers 146B and 146C of the adhesive member 146 are made equal, the adhesive surface between the adhesive layer 146B and the scintillator 71 is more than the adhesive surface between the adhesive layer 146C and the radiation detector 60 as described above. In addition, since the generation of voids proceeds, the number and size of the white defect portion increase before the black defect portion as shown in FIG. . Further, when the adhesive force of the adhesive layers 146B and 146C of the adhesive member 146 is set so that the adhesive force between the adhesive layer 146B and the scintillator 71 is equal to the adhesive force between the adhesive layer 146C and the radiation detector 60. As the contact member 146 deteriorates with time, as shown in FIG. 13A as an example, the number and size of white defect portions increase in the same manner as the number and size of black defect portions. 13A and 13B, based on the increase in the number and size of the black defect portions in the radiographic image, before the number and size of the white defect portions in the radiographic image clearly increase, It is difficult to detect that the number and size of white defect portions in a radiographic image are likely to increase.

  On the other hand, in the present embodiment, the adhesive force between the adhesive layer 146B and the scintillator 71 is higher than the adhesive force between the adhesive layer 146C and the radiation detector 60, and the void in the adhesive surface between the adhesive layer 146B and the scintillator 71. The adhesive force of the adhesive layers 146B and 146C of the contact member 146 is set so that the generation of the void in the contact surface between the adhesive layer 146C and the radiation detector 60 proceeds earlier than the occurrence of. Thereby, as shown in FIGS. 12A and 12B as an example, before the number of white defects in the radiographic image and the maximum size clearly increase, the number of black defects in the radiographic image and the maximum Increase in size.

  In the present embodiment, this is utilized, and the total number Nb of black defect portions is less than the threshold value Nbth for the number of black defect portions, and the maximum size Sb of the black defect portions is less than the threshold value Sbth for the maximum size of the black defect portions. In this case, the inspection result of the electronic cassette 32 is set to “usable”, while at least one of the conditions “the total number Nb of black defect portions is equal to or greater than the threshold value Nbth” and “the maximum size Sb of black defect portions is equal to or greater than the threshold value Sbth” is satisfied. If the condition is satisfied, the inspection result of the electronic cassette 32 is set to “use caution”, and further, “the total number Nb of black defect portions is greater than or equal to the allowable maximum value Nbmax” and “the maximum size Sb of black defect portions is equal to or greater than the allowable maximum value Sbmax”. When at least one of the conditions is satisfied, the inspection result of the electronic cassette 32 is “use prohibited”. Thus, based on the increase in the total number Nb and the maximum size Sb of black defect portions in the radiographic image, before the number of white defect portions and the maximum size in the radiographic image clearly increase, It is possible to detect that the number and the maximum size are likely to increase.

  Further, the inspection result set above is displayed on the display 110 of the console 42 by the electronic cassette inspection process (FIG. 9) described above. As a result, the inspection instructor recognizes that there is a high possibility that the number of white defect portions and the maximum size in the radiographic image will increase. For example, the electronic cassette 32 whose inspection result is “usable” The electronic cassette 32 that is used for all applications including diagnosis of cancer that requires a radiological image and has a test result of “careful use” is used only for applications such as diagnosis of a fracture that requires a relatively low level of image quality of the radiographic image. The electronic cassette 32 whose inspection result is “use prohibited” is not used, and the electronic cassette 32 that has been inspected is in accordance with the inspection result, such as arranging for rework such as replacement of the contact member 146. Appropriate measures can be taken.

  The threshold values Nbth and Sbth are examples of the threshold values described in claims 2 and 3 and the first threshold value of claim 4, and the allowable maximum values Nbmax and Sbmax are the second threshold values described in claim 4. It is an example of a threshold value. Steps 340 to 344, 350, and 352 are examples of processing by the determination unit according to claims 2, 4, and 6, and steps 348, 354, and 368 are examples of processing by the notification unit according to claim 3. Steps 358 and 368 are an example of processing by the prohibition processing means according to claim 4.

  Moreover, the relationship between the progress degree of the space | gap generation | occurrence | production in the contact surface of the adhesion layer 146B and the scintillator 71, and the progress degree of the space | gap generation | occurrence | production in the contact surface of the adhesion layer 146C and the radiation detector 60 is the relationship shown in FIG. May not match exactly, and there may be some variation. In consideration of this, when “usable” or “careful use” is set as the inspection result of the electronic cassette 32, in step 356, the central area and the peripheral area (see FIG. 11B) of the radiographic image are unit. The number Nw of white defect portions and the maximum size Sw are respectively calculated.

  In the next step 360, the total number Nw of white defect portions in the central area calculated in step 340 is greater than or equal to the threshold Nwth for the number of white defect portions, or the white defect portions in the central area calculated in step 340. It is determined whether or not the maximum size Sw is equal to or larger than a threshold value Swth for the maximum size of the white defect portion. This determination is negative if “the total number Nw of white defect portions in the central region is less than the threshold value Nwth” and “the maximum size Sw of white defect portions in the central region is less than the threshold value Swth”, and the process proceeds to step 364. Further, if either of the conditions “the total number Nw of white defect portions in the central region is greater than or equal to the threshold Nwth” and “the maximum size Sw of white defect portions in the central region is greater than or equal to the threshold Swth” is satisfied, If the determination is affirmed, the process proceeds to step 362, and information indicating that “the central area is prohibited” is additionally set in the inspection result of the electronic cassette 32, and then the process proceeds to step 364.

  In step 364, the total number Nw of white defect portions in the peripheral area calculated in step 340 is greater than or equal to the threshold Nwth, or the maximum size Sw of white defect portions in the peripheral area calculated in step 340 is greater than or equal to the threshold Swth. Determine whether. This determination is negative if “the total number Nw of white defect portions in the peripheral region is less than the threshold value Nwth” and “the maximum size Sw of white defect portions in the peripheral region is less than the threshold value Swth”, and the process proceeds to step 368.

  Further, if either of the conditions “the total number Nw of white defect portions in the peripheral region is equal to or greater than the threshold Nwth” or “the maximum size Sw of white defect portions in the peripheral region is equal to or greater than the threshold Swth” is satisfied, If the determination is affirmative, the process proceeds to step 366, and information indicating that “peripheral area is prohibited” is additionally set in the inspection result of the electronic cassette 32, and then the process proceeds to step 368. Note that the threshold value Nwth for the number of white defect portions may be different between the central region and the peripheral region according to the area ratio of the central region and the peripheral region. In step 368, the inspection result of the electronic cassette 32 is transmitted to the console 42, and the defect inspection process is terminated.

  The threshold values Nwth and Swth are examples of the threshold values described in claims 5 and 6. Steps 356, 360, and 364 are examples of processing by the determination means described in claims 5 and 6, and steps 362, 366, and 368 are examples of processing by the prohibition processing means described in claim 6.

  When the above-described processing of Step 356 to Step 366 causes gap generation in the adhesion surface between the adhesive layer 146B and the scintillator 71 to proceed relatively early, and white defect portions in the radiographic image increase relatively early. However, this can be detected reliably and can be recognized by the inspection instructor. In addition, the radiation image is divided into a central region and a peripheral region, the number Nw of white defect portions and the maximum size Sw are calculated for each region, and compared with threshold values (Nwth, Swth), for example, an inspection result Even if the electronic cassette 32 is “prohibited from use in the central area”, the white area in some areas is white so that the attention area in the radiographic image can be used for imaging a breast located in the peripheral area. The electronic cassette 32 in a state of waiting for rework such as replacement of the contact member 146 due to an increase in the number of defective portions can be effectively used for photographing with a region having a relatively small number of white defective portions as a region of interest. It becomes possible.

  In the above description, the radiation image is divided into the central region and the peripheral region, and the number Nw of white defect portions and the maximum size Sw are calculated for each region and compared with threshold values (Nwth, Swth). The radiation image may be divided into three or more regions, and the number Nb of black defect portions and the maximum size Sb are calculated and compared with threshold values (Nbth, Sbth) for each region. You may make it perform.

  In the above description, the mode in which the light emitted from the scintillator 71 is detected by the single light detection unit (radiation detector 60) has been described. However, the present invention is not limited to this. As an example, in FIG. 14, in addition to the radiation detector 60, a radiation detection unit 200 as a light detection unit that detects light emitted from the scintillator 71 is provided on the opposite side of the scintillator 71 with the radiation detector 60 interposed therebetween. Is shown. In the radiation detection unit 200, a wiring layer 202 having a patterned wiring and an insulating layer 204 are sequentially formed, and a plurality of sensor units 206 for detecting light emitted from the scintillator 71 and transmitted through the radiation detector 60 are formed thereon. Further, a protective layer 212 is formed on the sensor unit 206. In addition, the thickness of the radiation detection part 200 is about 0.05 mm, for example.

  The sensor unit 206 includes an upper electrode 210A and a lower electrode 210B, and a photoelectric conversion film 210C that absorbs light from the scintillator 71 and generates charges is disposed between the upper electrode 210A and the lower electrode 210B. ing. As the sensor unit 206 (photoelectric conversion film 210C), it is possible to apply a PIN type or MIS type photodiode using amorphous silicon, but in this embodiment, the same as the photoelectric conversion film 72C of the photoelectric conversion unit 72. In addition, the photoelectric conversion film 210C is made of an organic photoelectric conversion material. This makes it possible to form the photoelectric conversion film 210C by adhering the organic photoelectric conversion material onto the object to be formed using a droplet discharge head such as an inkjet head, and the insulating substrate 64 has light transmittance. It is possible to use a thin substrate made of a synthetic resin.

  The detection result of the radiation dose by the sensor unit 206 is read out via a signal processing unit (not shown) connected to the electrodes 210A and 210B, and for example, detection of radiation start / end timing of radiation to the electronic cassette 32, and electronic cassette 32 is used for detecting the integrated value of the radiation dose to 32. In addition, since the detection (imaging) of the radiation image is performed by the radiation detector 60, the sensor unit 206 of the radiation detection unit 200 has a larger arrangement pitch (lower arrangement density) than the pixel unit 74 of the radiation detector 60. In addition, the light receiving area of the single sensor unit 206 may have a size corresponding to several to several hundreds of the pixel units 74 of the radiation detector 60.

  In the above description, the inspection result of the electronic cassette 32 is transmitted to the console 42 and displayed on the display 110. However, the present invention is not limited to this. For example, the inspection result of the electronic cassette 32 is stored in the storage unit 92C. In addition, when a radiographic image is captured using the electronic cassette 32, the cassette control unit 92 captures, as a radiographic image capturing condition, at least one of an imaging region and a diagnostic use of the radiographic image to be captured. The information is acquired by receiving the information from the console 42, and the acquired imaging condition information is collated with the inspection result of the electronic cassette 32, thereby determining the suitability of radiographic imaging under the imaging conditions represented by the acquired imaging condition information. FIG. 15B shows an example of a display unit provided in the casing 54 of the electronic cassette 32 according to the determination result (an example of a display unit suitable for this mode). May be configured to perform processing of switching the display state of the No. are denoted the "220").

  The display unit 220 illustrated in FIG. 15B includes a display unit 220A that can display the appropriateness of radiographic image capturing in a plurality of levels, and a display unit that can display an appropriate orientation of the housing 54 during imaging. 220B. The display unit 220A includes a plurality of lamps composed of LEDs or the like, and can change the number of lamps to be turned on in accordance with the degree of suitability for photographing to display the degree of suitability for photographing in a plurality of levels. . One of the plurality of lamps is used as an imaging prohibition lamp by making the emission color different from that of the other lamps. For example, when the determination result of the suitability of radiographic imaging is “adequate imaging”, Only the photographing prohibition lamp may be turned on, and if photographing is possible, the photographing prohibition lamp may be turned off and the other lamps may be turned on.

  The display unit 220B includes a plurality of lamps for indicating different directions as directions of the casing 54 at the time of photographing, which are composed of LEDs or the like. In radiographic image capturing using the electronic cassette 32, the electronic cassette 32 is often arranged so that the subject (imaging target portion) is positioned at the center of the irradiation surface 56 of the housing 54. Although it is not necessary to display the proper orientation of the housing 54 at the time of photographing by the display unit 220B, for example, in photographing breasts, irradiation is performed by photographing one side of the housing 54 against the body of the subject. A subject is photographed at a position on the surface 56 that is biased toward one side that abuts against the body of the subject.

  For this reason, the cassette control unit 92 captures an image of the subject on one end of the irradiation surface 56 such that the imaging condition represented by the imaging condition information acquired from the console 42 is “imaging site is breast”, for example. If the condition is satisfied, an appropriate orientation of the housing 54 at the time of photographing (direction in which the subject is photographed in an area where the number and area of white defect portions are less than the threshold) is determined based on the inspection result of the electronic cassette 32. Depending on the determination result, any one of the plurality of lamps of the display unit 220B (for example, a lamp that points to one side of the body to be photographed when photographing breasts) is turned on. The proper orientation of the housing 54 at the time of shooting is displayed. Note that, as shown in FIG. 15A, as an example, when the proper orientation of the housing 54 at the time of imaging is displayed in four directions as in the display unit 220B shown in FIG. What is necessary is just to comprise so that the peripheral part area | region of an image may be divided | segmented into four or more partial areas, and the number and size of a white defect part may be determined for each partial area.

  In the above aspect, since the inspection result of the electronic cassette 32 (the result of collating with the imaging conditions) is displayed on the display unit 220 provided in the housing 54 of the electronic cassette 32, there are particularly a plurality of electronic cassettes 32. In the environment, it is possible to prevent the electronic cassette 32 suitable for photographing from being mistaken or photographed in a state where the casing 54 is oriented in an inappropriate direction. The above aspect is an example of the invention described in claims 7 and 8.

  In addition, it is needless to say that the configuration of the electronic cassette 32 as the radiographic image capturing apparatus according to the present invention described in the above embodiment is an example, and can be appropriately changed without departing from the gist of the present invention.

18 Radiation Imaging System 32 Electronic Cassette 34 Radiation Generator 42 Console 60 Radiation Detector 71 Scintillator 71A Columnar Crystal 146 Adhering Member 146A Supports 146B and 146C Adhesive Layer

Claims (10)

A scintillator that has a flat plate shape as a whole, has a columnar crystal structure, absorbs irradiated radiation, and emits light;
A light detection unit that is arranged in a flat plate shape so as to face the columnar crystal structure part of the scintillator, and detects light emitted from the scintillator as a radiation image;
Arranged between the scintillator and the light detection part, and is in close contact with the columnar crystal structure part of the scintillator on the first contact surface and in close contact with the light detection unit and the second contact surface, and is associated with deterioration over time. The adhesion force of the first adhesion surface and the adhesion force of the second adhesion surface are such that the generation of voids in the adhesion surface proceeds in the second adhesion surface rather than in the first adhesion surface. Each set contact member,
A radiographic imaging apparatus including: With respect to the radiographic image detected by the light detection unit, white defects appearing in the radiographic image due to voids generated in the first contact surface, and voids generated in the second contact surface Due to the black defect portion appearing in the radiological image, a defect detection means for detecting at least the black defect portion,
Determination means for determining whether at least one of the number and area of the black defect portions detected by the defect detection means is equal to or greater than a preset threshold;
The radiographic imaging apparatus according to claim 1, further comprising:   The radiographic image capturing apparatus according to claim 2, further comprising a notification unit that notifies when the determination unit determines that at least one of the number and area of the black defect portions is equal to or greater than a preset threshold value. The determination unit determines whether at least one of the number and area of the black defect portions detected by the defect detection unit is equal to or greater than a first threshold value set in advance, and the black defect portion It is also determined whether at least one of the number and the area is equal to or greater than a second threshold value that is greater than the first threshold value,
The image processing apparatus further includes a prohibition processing unit that performs an imaging prohibition process for prohibiting radiographic image capturing when the determination unit determines that at least one of the number and area of the black defect portions is equal to or greater than the second threshold. The radiographic imaging device of Claim 2 or Claim 3. The defect detection means also detects the white defect,
5. The method according to claim 1, wherein the determination unit also determines whether at least one of the number and area of the white defect portions detected by the defect portion detection unit is equal to or greater than a preset threshold value. The radiographic imaging device described in the item. The defect detection means distinguishes and detects the black defect portion and the white defect portion,
When the determination unit divides the radiographic image into a plurality of regions as to whether or not at least one of the number and area of the white defect portions detected by the defect portion detection unit is equal to or greater than a preset threshold value. For each individual area,
The prohibition processing unit uses, as the photographing prohibition processing, an area in which at least one of the number and area of the white defect portions is determined to be equal to or more than a preset threshold by the determination unit among the plurality of areas. The radiographic image capturing apparatus according to claim 4, wherein processing for prohibiting radiographic image capturing is performed. Storage means for storing a determination result by the determination means;
An acquisition means for acquiring imaging condition information representing at least one of an imaging region and a diagnostic use of the radiographic image to be acquired as an imaging condition of the radiographic image;
Display means capable of switching to a plurality of display states;
By comparing the imaging condition information acquired by the acquisition unit with the determination result stored in the storage unit, it is determined whether or not radiographic images are captured under the imaging condition represented by the imaging condition information, and determination is made. Display control means for switching the display state of the display means according to a result;
The radiographic imaging device according to any one of claims 2 to 6, further comprising: Among the plurality of display states of the display means includes a display state that instructs an appropriate orientation of the housing of the radiographic image capturing apparatus at the time of radiographic image capturing,
The defect detection means distinguishes and detects the black defect portion and the white defect portion,
When the determination unit divides the radiographic image into a plurality of regions as to whether or not at least one of the number and area of the white defect portions detected by the defect portion detection unit is equal to or greater than a preset threshold value. For each individual area,
The display control means is stored in the storage means when the imaging condition represented by the imaging condition information is an imaging condition in which the subject is imaged on one end side of the radiation irradiation surface of the housing. The radiographic imaging according to claim 7, wherein an appropriate orientation of the housing at the time of radiographic imaging is determined based on the determination result, and the display state of the display unit is switched to a display state instructing the determined appropriate orientation. apparatus.   The adhesion member is provided with a first adhesive layer for closely adhering to the scintillator on one surface of a support, and a second adhesive for closely adhering to the light detection unit on the other surface of the support. A layer is provided, and the adhesive force of the first adhesive layer and the adhesive force of the second adhesive surface are adjusted by adjusting the adhesive force of the first adhesive layer and the second adhesive layer. The radiographic imaging apparatus of any one of Claims 1-8 in which each force is set.   The radiation according to any one of claims 1 to 9, wherein radiation is incident from the light detection unit side of the scintillator and the light detection unit, and the scintillator is irradiated with radiation that has passed through the light detection unit. Radiation imaging device.

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