JP2010158379A - Portable radiation image photographing apparatus, and radiation image photographing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable radiation image photographing apparatus capable of falsely restoring the data of a subject of a saturated image data part in a case that image data, wherein a data value is saturated, is photographed. <P>SOLUTION: The portable radiation image photographing apparatus 1 is equipped with a detection part P wherein radiation detecting elements 7 producing charges corresponding to the dose of radiation are two-dimensionally arranged, a reading circuit 17 reading the charges from the respective radiation detecting elements 7 to convert the same to image data Fa, a determination means 22 analyzing the image data Fa to determine whether saturated image data FA are present, a feature quantity calculating means 22 allowing the reading circuit 17 to again perform reading processing without performing the reset processing to the respective radiation detecting elements 7 in a case that the saturated image data FA is determined to be present and calculating respective feature quantities C on the basis of reread image data Fb and a correction means 22 correcting the respective saturated image data FA to unsaturated image data Fa<SP>*</SP>on the basis of the respective calculated feature quantities C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a portable radiographic imaging device and a radiographic imaging system.

  For the purpose of disease diagnosis and the like, radiographic images taken using radiation typified by X-ray images are widely used. Conventionally, such medical radiographic images have been taken using a screen film. In order to digitize radiographic images, CR (Computed Radiography) devices using stimulable phosphor sheets have been developed recently. Then, a radiation image capturing apparatus has been developed in which irradiated radiation is detected by a radiation detection element arranged in a two-dimensional form and acquired as digital image data.

  This type of radiographic imaging device is known as an FPD (Flat Panel Detector), and has been conventionally formed integrally with a Bucky device (see, for example, Patent Document 1). In recent years, a portable radiographic imaging apparatus in which a radiation detection element or the like is accommodated in a housing has been developed and put into practical use (see, for example, Patent Document 2).

  However, there are many cases where CR devices are still used for radiographic imaging, and when a radiographic imaging device (FPD) is introduced there, so-called CR devices and radiographic imaging devices are mixed in the imaging room. A state arises. Thus, in the presence of such CR devices and radiographic imaging devices, there has been proposed a radiographic imaging system for constructing an environment in which an operator such as a radiographer has good work efficiency and is easy to work ( (See Patent Document 3).

  By the way, it is known that the radiation image capturing apparatus requires a lower radiation dose than that of the CR apparatus in order to obtain a predetermined level of image data. In other words, in order to obtain a predetermined level of image data, if the radiation imaging device (FPD) is accidentally irradiated with radiation of an irradiation dose to be irradiated to the CR device, the output image data is saturated. (Saturate) occurs. There is a high possibility that this problem will occur particularly in an environment where a CR device and a radiographic image capturing device coexist in a photographing room.

  Therefore, for example, in Patent Document 4, when performing density adjustment processing or contrast adjustment processing of image data captured by a radiographic image capturing apparatus, when there is image data that is determined to be saturated, It has been proposed to perform density adjustment and contrast adjustment by adding a constant to saturated image data.

JP-A-9-73144 JP 7-246199 A JP 2001-149358 A JP 2000-137099 A

  However, if a constant is added to saturated image data, the density relationship and contrast relationship between saturated image data and non-saturated image data are improved, but there is a difference in the data values between the saturated image data. First, in the radiographic image, the saturated portion of the image data eventually appears white (or black).

  As described above, according to the method described in Patent Document 4, information on a subject that should have been captured in the saturated image data portion cannot be displayed on the radiation image, and thus re-imaging is necessary. However, this increases the burden on the patient and increases the exposure dose to the patient, which is not preferable.

  The present invention has been made in view of the above problems, and when image data with a saturated data value is taken, portable radiation that can artificially restore information on the subject of the saturated image data portion. An object of the present invention is to provide an image capturing apparatus and a radiation image capturing system.

In order to solve the above problem, the portable radiographic imaging device of the present invention is:
A detection unit in which a plurality of radiation detection elements that generate an electric charge according to a dose of radiation carrying information on a subject are arranged two-dimensionally;
A readout circuit that performs a readout process of reading out the charge from each radiation detection element and converting the charge into image data for each radiation detection element;
Determining means for analyzing the image data and determining whether there is saturated image data in which a data value is saturated;
When the determination means determines that the saturated image data exists, the read circuit is caused to perform the read process again without performing the reset process for each radiation detection element, and the saturated image data is handled. A feature amount calculating means for calculating a feature amount based on the image data read again,
Correction means for correcting each of the saturated image data to non-saturated image data based on each feature quantity calculated by the feature quantity calculation means,
It is characterized by providing.

Moreover, the radiographic imaging system of the present invention is
A detection unit in which a plurality of radiation detection elements that generate an electric charge according to a dose of radiation carrying information on a subject are arranged two-dimensionally;
A readout circuit that performs a readout process of reading out the charge from each radiation detection element and converting the charge into image data for each radiation detection element;
Determining means for analyzing the image data and determining whether there is saturated image data in which a data value is saturated;
Control means for causing the readout circuit to perform the readout process again without performing a reset process on each of the radiation detection elements when the judgment means determines that the saturated image data is present;
A communication means for transmitting / receiving data to / from an external device;
A portable radiographic imaging device comprising:
Communication means for transmitting and receiving data to and from the portable radiographic imaging device is provided, and the image data including the saturated image data and the image data read again are transmitted from the portable radiographic imaging device. And calculating feature values based on the read image data corresponding to the saturated image data, and correcting the saturated image data to unsaturated image data based on the calculated feature values. Console to
It is characterized by providing.

  According to the radiographic image capturing apparatus and radiographic image capturing system of the present invention, the lag phenomenon (see US Pat. No. 6,621,887) occurs when radiation is irradiated so that the image data is saturated. The phenomenon that the effect of radiation irradiation at the current imaging is superimposed on the radiographic image reading data at the next imaging) occurs, and the lag that is read out by re-reading processing is disclosed. The larger the data value resulting from is, the larger the feature amount is associated with the irradiation of the intense radiation, thereby making it possible to restore the subject information in the saturated image data portion in a pseudo-accurate manner.

  Therefore, for example, even when a radiation image capturing apparatus (FPD) is irradiated with a high dose of radiation that mistakenly irradiates the CR apparatus, and the saturation image data is partially captured, the saturation image data portion Because it is possible to obtain a radiation image in which information on the subject of the subject is restored in a pseudo and accurate manner, there is no need to perform re-imaging, and re-imaging increases the burden on the patient and the dose to the patient. It is possible to prevent the increase.

It is a perspective view which shows the radiographic imaging apparatus which concerns on this embodiment. It is sectional drawing which follows the AA line in FIG. It is a top view which shows the structure of the board | substrate which concerns on this embodiment. FIG. 4 is an enlarged view showing a configuration of an imaging element, a thin film transistor, and the like formed in a small region on the substrate of FIG. 3. It is sectional drawing which follows the XX line in FIG. It is a side view explaining the board | substrate with which COF, a PCB board | substrate, etc. were attached. It is a figure showing the equivalent circuit schematic of the radiographic imaging apparatus which concerns on this embodiment. 6 is a timing chart in a normal case where re-reading processing is not performed. (A) It is a top view explaining the detection part in the radiation entrance plane of a radiographic imaging apparatus, the area | region which a to-be-photographed object, the area | region where radiation is irradiated, etc., (B) is a graph which shows the example of the read image data is there. It is a graph which shows the example of the image data in which saturated image data exists. It is a timing chart in the case of performing read-out processing again. It is a graph which shows the example of the image data read by the read-out process again. It is a graph explaining the unread data value in the graph of FIG. It is a graph which shows the relationship between the dose of a radiation, and the reading efficiency from a radiation detection element. It is a graph which shows the example of the feature-value matched with the lag data value. It is a graph which shows the example of the saturation image data to which the feature-value was added. FIG. 17 is a graph showing an example of image data obtained by data conversion by multiplying each data of FIG. 16 by a predetermined coefficient. FIG. It is a figure which shows the whole structure of the radiographic imaging system which concerns on this embodiment.

  Embodiments of a portable radiographic imaging device and a radiographic imaging system according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following illustrated examples.

  Hereinafter, the portable radiographic imaging device is simply referred to as a radiographic imaging device. In the following, a so-called indirect radiation image capturing apparatus that includes a scintillator or the like as a radiation image capturing apparatus, converts the emitted radiation into electromagnetic waves of other wavelengths such as visible light, and obtains an electrical signal with a radiation detection element. However, the present invention can also be applied to a so-called direct type radiographic imaging apparatus that directly detects radiation with a radiation detection element without using a scintillator or the like.

[Radiation imaging equipment]
First, the radiographic imaging device according to the present embodiment will be described. FIG. 1 is an external perspective view of the radiographic image capturing apparatus according to the present embodiment, and FIG. 2 is a cross-sectional view taken along line AA in FIG. The radiographic imaging apparatus 1 according to the present embodiment is a cassette-type portable radiographic imaging apparatus in which a scintillator 3, a substrate 4, and the like are housed in a housing 2 as shown in FIGS. 1 and 2. It is configured.

  The housing 2 is formed of a material such as a carbon plate or plastic that transmits radiation at least on a surface R (hereinafter referred to as a radiation incident surface R) that receives radiation. 1 and 2 show a case where the housing 2 is a lunch box type formed by the frame plate 2A and the back plate 2B, but the housing 2 is formed integrally, for example, A so-called monocoque type, such as the X-ray imaging apparatus described in Japanese Unexamined Patent Publication No. 2002-31526, can also be used.

  As shown in FIG. 2, a base 31 is disposed on the lower side of the substrate 4 inside the housing 2, and the base 31 includes a PCB substrate 33 on which electronic components 32 and the like are disposed, and a buffer member. 34 etc. are attached. Further, in the present embodiment, the radiation that has entered the lower surface side of the base 31 and the PCB substrate 33 from the radiation incident surface R side of the radiographic imaging apparatus 1 and has passed through the scintillator 3, the substrate 4, the base 31, and the like. A radiation sensor 35 for detection is attached. A glass substrate 36 for protecting the substrate 4 and the scintillator 3 on the radiation incident surface R side is disposed.

  The scintillator 3 is, for example, a phosphor whose main component is converted into an electromagnetic wave having a wavelength of 300 to 800 nm, that is, an electromagnetic wave centered on visible light when it receives radiation, and that is output. The scintillator 3 is attached to a detection unit P, which will be described later, of the substrate 4.

  In the present embodiment, the substrate 4 is formed of a glass substrate. As shown in FIG. 3, a plurality of scanning lines 5 and a plurality of signal lines are provided on a surface 4 a of the substrate 4 facing the scintillator 3. 6 are arranged so as to cross each other. In each of the small regions r defined by the plurality of scanning lines 5 and the plurality of signal lines 6 on the surface 4a of the substrate 4, radiation detection elements 7 that are photoelectric conversion elements in the present embodiment are provided. In this way, the radiation detection elements 7 are two-dimensionally arranged on the substrate 4, and the entire region r in which the plurality of radiation detection elements 7 are provided, that is, the region indicated by the alternate long and short dash line in FIG. P.

  In the present embodiment, as the radiation detection element 7, the radiation incident from the radiation incident surface R is converted by the scintillator 3 and output, according to the amount of electromagnetic waves (increased according to the radiation dose incident on the scintillator 3). For example, a phototransistor or the like can also be used. Each radiation detection element 7 is connected to a source electrode 8s of a TFT (thin film transistor) 8 as a switch element, as shown in the enlarged views of FIGS. The drain electrode 8 d of the TFT 8 is connected to the signal line 6.

  When the TFT 8 is turned on, that is, when a voltage for signal readout is applied to the gate electrode 8g and the gate of the TFT 8 is opened, the charge accumulated in the radiation detection element 7 is applied to the signal line 6. It is supposed to be released. Here, the structure of the radiation detection element 7 and the TFT 8 in this embodiment will be briefly described with reference to the cross-sectional view shown in FIG. FIG. 5 is a sectional view taken along line XX in FIG.

A gate electrode 8g of a TFT 8 made of Al, Cr or the like is formed on the surface 4a of the substrate 4 so as to be integrally laminated with the scanning line 5, and silicon nitride (laminated on the gate electrode 8g and the surface 4a). The first electrode 74 of the radiation detecting element 7 is connected to the upper portion of the gate electrode 8g on the gate insulating layer 81 made of SiN _x ) or the like via the semiconductor layer 82 made of hydrogenated amorphous silicon (a-Si) or the like. The formed source electrode 8s and the drain electrode 8d formed integrally with the signal line 6 are laminated.

The source electrode 8s and the drain electrode 8d are divided by a first passivation layer 83 made of silicon nitride (SiN _x ) or the like, and the first passivation layer 83 covers both the electrodes 8s and 8d from above. In addition, ohmic contact layers 84a and 84b formed in an n-type by doping hydrogenated amorphous silicon with a group VI element are stacked between the semiconductor layer 82 and the source electrode 8s and the drain electrode 8d, respectively. The TFT 8 is formed as described above.

  In the radiation detecting element 7, an auxiliary electrode 72 is formed by laminating Al, Cr, or the like on the insulating layer 71 formed integrally with the gate insulating layer 81 on the surface 4 a of the substrate 4. A first electrode 74 made of Al, Cr, Mo or the like is laminated on the auxiliary electrode 72 with an insulating layer 73 formed integrally with the first passivation layer 83 interposed therebetween. The first electrode 74 is connected to the source electrode 8 s of the TFT 8 through the hole H formed in the first passivation layer 83.

  On the first electrode 74, an n layer 75 formed in an n-type by doping a hydrogenated amorphous silicon with a group VI element, an i layer 76 which is a conversion layer formed of hydrogenated amorphous silicon, and a hydrogenated amorphous A p layer 77 formed by doping a group III element into silicon and forming a p-type layer is formed by laminating sequentially from below. The order of stacking the p layer 77, the i layer 76, and the n layer 75 may be reversed.

  On the p layer 77, a second electrode 78 made of a transparent electrode such as ITO is laminated and formed so that the irradiated electromagnetic wave reaches the i layer 76 and the like. The radiation detection element 7 is formed as described above. In the present embodiment, as described above, a case where a so-called pin type radiation detection element formed by stacking the p layer 77, the i layer 76, and the n layer 75 is used as the radiation detection element 7 has been described. The radiation detection element 7 is not limited to such a pin-type radiation detection element.

A bias line 9 for applying a reverse bias voltage to the radiation detection element 7 is connected to the upper surface of the second electrode 78 of the radiation detection element 7 via the second electrode 78. The second electrode 78 and the bias line 9 of the radiation detection element 7, the first electrode 74 extended to the TFT 8 side, the first passivation layer 83 of the TFT 8, that is, the upper surfaces of the radiation detection element 7 and the TFT 8 are A second passivation layer 79 made of silicon nitride (SiN _x ) or the like is covered from above.

  As shown in FIGS. 3 and 4, in this embodiment, one bias line 9 is connected to a plurality of radiation detection elements 7 arranged in rows, and each bias line 9 is connected to a signal line 6. Are arranged in parallel with each other. In addition, each bias line 9 is bound to one connection 10 at a position outside the detection portion P of the substrate 4. The bias line 9 and the connection 10 are formed of a metal wire having a small electric resistance.

  In the present embodiment, the connection lines 10 of the scanning lines 5, the signal lines 6, and the bias lines 9 are respectively connected to input / output terminals (also referred to as pads) 11 provided near the edge of the substrate 4. As shown in FIG. 6, a COF (Chip On Film) 12 in which a chip such as an IC 12a is incorporated in each input / output terminal 11 is an anisotropic conductive adhesive film (Anisotropic Conductive Film) or anisotropic conductive paste (Anisotropic paste). It is connected via an anisotropic conductive adhesive material 13 such as Conductive Paste).

  The COF 12 is routed to the back surface 4b side of the substrate 4 and connected to the PCB substrate 33 described above on the back surface 4b side. Thus, the board | substrate 4 part of the radiographic imaging apparatus 1 is formed.

  On the other hand, as shown in FIG. 1, a power switch 37 of the radiographic imaging apparatus 1, an indicator 38 for displaying various operation statuses, and the like are provided on one side of the short side of the housing 2. Further, a cover member 39 for replacing an internal battery (not shown) is provided on the side surface portion, and the radiographic image capturing apparatus 1 transmits and receives data, signals, and the like to and from an external device in a wireless manner on the cover member 39. An antenna device 40 for performing is embedded and provided.

  The location where the antenna device 40 is provided is not limited to one short side surface portion of the housing 2 as in the present embodiment, and may be provided at another position. Further, the number of antenna devices 40 is not necessarily limited to one, and a necessary number is provided as appropriate.

  Here, the circuit configuration of the radiation image capturing apparatus 1 will be described. FIG. 7 is an equivalent circuit diagram of the radiation image capturing apparatus 1 according to the present embodiment.

  As described above, each radiation detection element 7 of the detection unit P of the substrate 4 has the second electrode 78 connected to the bias line 9 and the connection 10, respectively, and the connection 10 is connected to the reverse bias power supply 14. . The reverse bias power supply 14 supplies a reverse bias voltage to be applied to each radiation detection element 7 via the connection 10 and each bias line 9. The reverse bias power supply 14 is connected to the control means 22, and the control means 22 controls the reverse bias voltage applied to each radiation detection element 7 from the reverse bias power supply 14.

  The first electrode 74 of each radiation detection element 7 is connected to the source electrode 8s (denoted as S in FIG. 7) of the TFT 8, and the gate electrode 8g of each TFT 8 (denoted as G in FIG. 7). Is connected to each scanning line 5 extending from the scanning drive circuit 15. Further, the drain electrode 8 d (denoted as D in FIG. 7) of each TFT 8 is connected to each signal line 6.

  When a signal readout voltage is applied from the scanning drive circuit 15 to the gate electrode 8g of the TFT 8 via the scanning line 5, the gate of the TFT 8 is turned on, and the charge accumulated in the radiation detection element 7 is supplied to the source of the TFT 8. The signal is read out from the drain electrode 8d to the signal line 6 through the electrode 8s.

  Each signal line 6 is connected to each readout circuit 17 formed in the readout IC 16. Note that a predetermined number of readout circuits 17 are provided in the readout IC 16, and by providing a plurality of readout ICs 16, readout circuits 17 corresponding to the number of signal lines 6 are provided.

  The readout circuit 17 includes an amplifier circuit 18, a correlated double sampling circuit 19, and an A / D converter 20, and one circuit is provided for each signal line 6. However, in the present embodiment, the A / D converter 20 is common to a plurality of circuits, and each electric signal output from each correlated double sampling circuit 19 is sequentially supplied to the A / D converter 21 via the analog multiplexer 21. The data is transmitted to the D converter 20 and is sequentially converted into digital values (0 to 4095 in this embodiment) by the A / D converter 20.

  In the readout circuit 17, charges are read from the radiation detection elements 7 through the signal lines 6, and the charges are converted into electric signals by performing charge-voltage conversion and amplification for each radiation detection element 7. ing. The correlated double sampling circuit 19 is represented as CDS in FIG.

  The control means 22 is composed of a microcomputer equipped with a CPU (Central Processing Unit) or the like or a dedicated control circuit, and controls the operation of each member of the radiographic image capturing apparatus 1. The control means 22 is connected to a storage means 23 composed of a RAM (Random Access Memory) or the like.

  As described above, the control means 22 controls the reverse bias power supply 14 to control the reverse bias voltage applied to each radiation detection element 7 or the scanning line 5 for applying a signal readout voltage from the scanning drive circuit 15. Or by controlling the amplification circuit 18 and the correlated double sampling circuit 19 in each readout circuit 17 to read out the electrical signal from each radiation detection element 7.

  The control unit 22 is connected to the antenna device 40 described above, and is further connected to a battery 41 for supplying power to each member such as each radiation detection element 7. As described above, the battery 41 is built in the housing 2 of the radiographic imaging apparatus 1, and the battery 41 has a connection terminal 42 for supplying power from the external device to the battery 41 to charge the battery 41. It is attached. The control unit 22 is connected to the radiation sensor 35 described above.

  In the present embodiment, as described above, the start and end of radiation irradiation to the radiographic imaging device 1 are detected based on the radiation dose detected by the radiation sensor 35, as will be described later. When the radiation imaging apparatus 1 is irradiated with radiation, charges flow out from the radiation detection elements 7 to the bias line 9 and the connection 10, so that the outflow of the charges, that is, the current is detected to irradiate the radiation imaging apparatus 1 with radiation. It is also possible to configure so as to detect the start and end. Moreover, it is also possible to notify the radiation imaging apparatus 1 of the start or end of radiation irradiation via an antenna device 40 from an external device such as a radiation generator.

  The control unit 22 functions as a determination unit, a feature amount calculation unit, and a correction unit in the present invention. Hereinafter, this point will be described, and the operation of the radiation image capturing apparatus 1 according to the present embodiment will be described.

  In the present embodiment, the control means 22 is configured such that the operator manually operates the power switch 37 (see FIG. 1) or the like, or externally such as a console 58 of the radiographic imaging system 50 to be described later via the antenna device 40. When the signal transmitted from the apparatus is received, the radiation detection element 7 and the readout circuit 17 are reset.

  In the reset process, as shown in the timing chart of FIG. 8, the control unit 22 causes the scanning drive circuit 15 to supply voltage for signal readout to all the lines L1 to Ln of the scanning line 5, and to the scanning line 5. A voltage for signal readout is applied to the gate electrode 8g of each TFT 8 connected (time T1), each TFT 8 is turned on, and a predetermined signal is transmitted also to the readout circuit 17, whereby the radiation detection element 7 and the TFT 8 are transmitted. Then, excess charges accumulated in the amplifier circuit 18 and the like of the readout circuit 17 are released to the downstream side.

  When the reset process is completed, the control unit 22 stops supplying the signal reading voltage to all the scanning lines 5 from the scanning drive circuit 15 (time T2), and reads the signal to the gate electrode 8g of each TFT 8. The application of the voltage is stopped and each TFT 8 is turned off to stand by. Then, radiographic imaging is performed.

  In radiographic imaging, the affected part of a patient as a subject is placed on or close to the radiation incident surface R side of the radiographic imaging apparatus 1, and radiation is emitted from a radiation generator (not shown) to the radiographic imaging apparatus 1. Irradiated. In this embodiment, at this time, the start of radiation irradiation to the radiographic imaging apparatus 1 is detected based on the radiation dose information output from the radiation sensor 35, but the current flowing through the bias line 9 and the connection line 10 is detected. As described above, the start of radiation irradiation may be detected and the start of radiation irradiation may be notified via an antenna device 40 from an external device such as a radiation generator.

  When radiation that passes through the subject and carries information about the subject is irradiated onto the radiation incident surface R of the radiation imaging apparatus 1, the radiation that has passed through the radiation incident surface R enters the scintillator 3. Then, it is converted into an electromagnetic wave by the scintillator 3, and the electromagnetic wave is incident on the radiation detecting element 7 below the electromagnetic wave.

  Then, when the incident electromagnetic wave reaches the i layer 76 (see FIG. 5) of the radiation detection element 7, an electron-hole pair is generated according to the amount of the electromagnetic wave incident in the i layer 76 (that is, the radiation dose), One of the generated electrons and holes (in this embodiment, a hole) moves to the second electrode 78 side in accordance with a predetermined potential gradient formed in the radiation detection element 7 by the application of the reverse bias voltage. The other electric charge (electrons in this embodiment) moves to the first electrode 74 side and is accumulated near the first electrode 74.

When the irradiation of radiation is completed, the control unit 22 performs a process of reading out charges from each radiation detection element 7. In the reading process, the control means 22 supplies a signal reading voltage from the scanning drive circuit 15 to the predetermined line L1 of the scanning line 5, and the gate electrode 8g of each TFT 8 connected to the scanning line 5 (L1). A voltage for signal readout is applied to (T3 _{1 in} FIG. 8), each TFT 8 is turned on, and the charge accumulated from each radiation detection element 7 is read out to the signal line 6 via the TFT 8.

  The electric charges emitted from the radiation detection elements 7 to the signal lines 6 are converted into image data Fa by being subjected to charge-voltage conversion and amplification in the readout circuit 17, and sequentially A / D converters via the analog multiplexer 21. 20, converted into a digital value, and output to the storage means 23. The control unit 22 sequentially stores the output image data Fa in the storage unit 23 while associating it with the radiation detection element 7.

When the control unit 22 completes the reading process for the line L1 of the scanning line 5, the scanning line 5 to which a signal reading voltage is supplied from the scanning drive circuit 15 is sequentially switched to the lines L2, L3,. That is, by repeating the above-described reading process (while scanning) (time T3 _{2 to} T3 _n ), the charges are discharged from all the radiation detection elements 7 and converted into image data Fa, respectively, and the image data Fa is detected by radiation. The information is sequentially stored in the storage unit 23 while being associated with the element 7. In this way, the reading process is performed.

  Subsequently, as a determination unit, the control unit 22 analyzes each read image data Fa, and image data FA (hereinafter, referred to as saturated image data FA) in which the data value is considered to be saturated in each image data Fa. .) Is present.

  In the present embodiment, as described above, the image eater Fa can take 0 to 4095 as a digital data value, but the control means 22 does not only have the data value of the upper limit value 4095 but also the data value has a predetermined threshold value. When the value is (for example, 4000) or more, it is determined that the image data Fa is saturated image data FA, and it is determined that the saturated image data FA exists.

  However, normally, in radiographic imaging, as shown in FIG. 9A, the subject O is an area corresponding to the detector P on the radiation incident surface R of the radiographic imaging apparatus 1 (that is, a radiographable area). Radiation is applied to the area Ri including the occupied area Ro, and at that time, the radiation reaches directly without passing through the subject O (or is irradiated with an electromagnetic wave converted by the scintillator 3 where the radiation reaches directly). In the detection element 7, the data value of the image data Fa increases.

  That is, in FIG. 9A, among the plurality of radiation detection elements 7 arranged two-dimensionally in the detection unit P, for example, each radiation detection in each column j of one row i indicated by a one-dot chain line in the figure. When attention is paid to the elements 7 and a data profile is created for the image data Fa of the radiation detection elements 7, the data profile reaches directly without passing through the subject O as shown in FIG. 9B, for example. The data value of the image data Fa of the radiation detection element 7 (the data value of the Ri portion in the profile) is the data value of the image data Fa of the radiation detection element 7 that has reached the radiation transmitted through the subject O (the value of Ro in the profile). (Relative data value).

  In some cases, the data value of the image data Fa in the area Ri takes a value equal to or greater than the threshold value set to 4000 or the like, but the image data Fa in the area Ri does not pass through the subject O. In this case, the information about the subject O is not included in the image data Fa of the area Ri, and therefore the image data Fa of the area Ri is saturated. No problem. The saturation of the image data Fa becomes a problem with respect to the image data Fa of the radiation detection element 7 existing in the region Ro where the radiation transmitted through the subject O has arrived.

  Therefore, in this embodiment, the control means 22 which is a determination means is provided for each radiation detection element 7 for each row i (or for each column j) of a plurality of radiation detection elements arranged two-dimensionally in the detection unit P. A data profile as shown in FIG. 9B is created for each of the image data Fa. In the data profile, the image data Fa of the radiation detection element 7 in which the radiation directly reaches the portion where the data value existing at the end of the profile is large (the portion close to the output upper limit 4095) without passing through the subject O. The radiation detection element that the radiation that has passed through the subject O reaches the area Ri inside the area Ri and the area inside the area where the data value of the image data Fa is smaller than the data value of the image data Fa of the area Ri 7 is estimated to be the region Ro of the image data Fa.

  Then, the image data Fa in the region Ro in the estimated profile is analyzed, and based on the above criteria, it is determined whether or not the saturated image data FA exists in each image data Fa. .

  When the profile created for the image data Fa of each radiation detection element 7 in a predetermined row i of a plurality of radiation detection elements arranged two-dimensionally in the detection unit P is a profile as shown in FIG. It is determined that the saturated image data FA does not exist in the region Ro. In such a case, in this embodiment, as shown in the timing chart of FIG. 8, the control unit 22 subsequently performs a dark reading process after performing a reset process on each radiation detection element 7.

  In the case where there is no saturated image data portion and the image data value is generally higher or lower, by adjusting the LUT (Look Up Table) etc. at the stage of digital image processing (tone processing), Needless to say, it is possible to display even image data of an appropriate density range and contrast.

  In the reset process after the readout process, the charges remaining in the radiation detection elements 7 without being read out in the readout process are removed from the charges generated in the radiation detection elements 7 by radiation irradiation in radiographic imaging. Therefore, one or more reset processes are performed as necessary (time T4 to T5). In the reset process, as in the reset process before radiographic image capturing described above, a signal for reading a signal is applied from the scan drive circuit 15 to the gate electrode 8g of each TFT 8 via all the lines L1 to Ln of the scan line 5. When applied, each TFT 8 is turned on to release excess charge, and when the reset process is completed, the application of the signal reading voltage is stopped and each TFT 8 is turned off. This is done once or multiple times.

In the dark reading process, while the TFTs 8 are turned off for radiographic imaging (that is, between times T2 and T3 _x (x = 1 to n)), the dark reading process is performed separately from the charges generated by the irradiated radiation. This process is performed to acquire the offset of the image data Fa due to the so-called dark charge generated by excitation or the like, and the true value is obtained by subtracting this offset from each image data Fa read out in the readout process described above. Image data Fa is obtained.

The dark reading process, as each TFT8 time T5 is turned off, without irradiating the radiation image capturing apparatus 1, the time for each line L1~Ln scanning lines 5 T5~T6 _{x (x} = 1 to n), the radiation image capturing apparatus 1 is left for the same period ΔT _{1 to} ΔT _n as in the case of capturing a radiation image, and dark charges are accumulated in each radiation detection element 7.

Then, after each period ΔT _{1 to} ΔT _n has passed, the lines L _{1 to} Ln of the scanning line 5 that supplies the signal reading voltage from the scanning driving unit 15 are sequentially switched at the same timing as the above-described reading process. The dark charge accumulated in the radiation detecting element 7 is read out, and the read dark charge is converted into a charge voltage by the read circuit 17 and amplified in the same manner as in the above read processing, and stored as dark read values, respectively. 23.

  The dark reading value obtained in this way can be used as it is for the above-mentioned offset, and for example, the above-described dark reading processing is performed a plurality of times to obtain each radiation detection element 7. It is also possible to configure such that the average value of the dark reading values obtained for a plurality of times is used as an offset amount. Note that the dark reading process may be performed before radiographic image capturing.

  In the region Ro that has been estimated to be the region Ro of the image data Fa of the radiation detection element 7 to which the radiation that has passed through the subject O has arrived in the data profile of the image data Fa as shown in FIG. 9B. This processing is performed when it is determined that the saturated image data FA does not exist in each image data Fa. However, if the saturated image data FA exists in each image data Fa in the region Ro, The processing when the determination is made will be described below.

  When the image data Fa is saturated (that is, when it is saturated image data FA), for example, an image of each radiation detection element 7 in each column j of one row i indicated by a one-dot chain line in FIG. 9A. When a data profile is created for the data Fa, the data profile becomes, for example, a profile shown in FIG. The data value Flost lost because the image data FA is saturated cannot normally be restored by processing the saturated image data FA itself, that is, the data value itself near the upper limit 4095.

  Therefore, the present inventors read out charges from each radiation detection element 7 again without performing a reset process on each radiation detection element 7 immediately after the readout process when saturated image data FA exists, and image It was considered that the read processing for converting to the data Fb is performed, and the saturated image data FA is corrected by the image data Fb read by the second read processing.

In this case, as shown in the timing chart of FIG. 11, the first read processing (time T3 _{1) is performed} while sequentially switching the scanning line 5 for supplying the signal read voltage from the scan drive circuit 15 to the lines L1, L2,. After repeating ~ T3 _n ), a profile is created for the image data Fa of each radiation detection element 7 in each row i of a plurality of radiation detection elements arranged two-dimensionally in the detection unit P.

Then, the region Ro of the image data Fa of the radiation detection element 7 to which the radiation transmitted through the subject O has arrived is estimated, the image data Fa in the region Ro is analyzed, and the saturated image data FA exists in each image data Fa. It is determined whether or not to do. If it is determined that the saturated image data FA exists in each image data Fa, unlike the timing chart shown in FIG. 8, each radiation detection element 7 is again reset without performing the reset process of each radiation detection element 7. 7 performs a read process (time T7 _{1 to} T7 _n ) for reading out the charges from 7 and converting them into image data Fb.

  In this way, for example, when the readout process is performed again for each radiation detection element 7 in each column j of the row i of the detection unit P in which the profile of the image data Fa illustrated in FIG. 10 is obtained in the first readout process, In this re-reading process, it has been found that a profile substantially similar to the lost data is obtained, such as the profile of the image data Fb as shown in FIG.

  When the profile of the image data Fb obtained by this re-reading process is analyzed, first, the data of the image data Fb of each radiation detection element 7 is shown as hatched in FIG. 13, which is the same profile as FIG. It can be seen that the value is not 0, and some positive value is output.

This is data resulting from dark charges accumulated in each radiation detection element 7 during the period from the first readout process (time T3 _{1 to} T3 _{n in} FIG. 11) to the second readout process (time T7 _{1 to} T7 _n ). Since the reading efficiency of the value and the charge read out in one reading process from each radiation detection element 7 is not 100%, the unread portion that was not read out in the first reading process is read out in the re-reading process. This is considered to be a data value or the like resulting from this. Hereinafter, this data value including the dark charge will be referred to as unread data value Dr.

  For example, as shown in FIG. 14, the reading efficiency from the radiation detection element 7 varies depending on the dose of radiation applied to the radiation detection element 7, but usually from the radiation detection element 7 in one reading process. Is not 100%. For example, when the radiation dose is 10 [mR], the reading efficiency in one reading process is only about 90%, and the remaining unread about 10% is read out by a second reading process.

  However, as shown in FIG. 13, the radiation directly reaches the subject O without passing through the subject O, and the image data Fb of the radiation detecting element 7 irradiated with a strong dose of radiation, that is, the image data Fb of the Ri portion in the profile. Becomes a large data value that is significantly different from such unread data value Dr. This is considered to be a data value caused by so-called lag, which is different from the dark charge and the unread portion as described above. Hereinafter, this data value is referred to as a lag data value Dl.

  The lag is a phenomenon in which afterimages are repeatedly read from the radiation detection element 7 for each readout process every time the readout process is repeated when the radiation detection element 7 is irradiated with strong radiation (the above-mentioned US). Patent 6,621,887 specification etc.). Then, as shown in FIG. 13, the inventors, in the re-reading process, the lag data value D1 considered to be caused by this lag is not only the Ri portion in the profile but also the Ro portion in the profile. In addition, it has been found that the saturation image data FA also appears in the portion of the radiation detection element 7s (see FIGS. 10 and 13) from which the saturated image data FA has been read out in the first readout process.

  Therefore, in the present invention, attention is paid to the lag data value Dl read out by the re-reading process from the radiation detection element 7s from which the saturated image data FA has been read out by the first read-out process, and the first read-out process is performed using them. The saturated image data FA read out in step 1 is restored.

  Specifically, when the profile of the image data Fa of each radiation detection element 7 read out in the first readout process is a profile as shown in FIG. 10, as described above, the control means as the determination means 22 analyzes the image data Fa in the region Ro estimated to be the region Ro of the image data Fa of the radiation detection element 7 to which the radiation that has passed through the subject O has arrived, and includes in each image data Fa. It is determined whether or not the saturated image data FA exists.

  If it is determined that the saturated image data FA exists, the readout process is performed again. Then, when the profile of the image data Fb as shown in FIG. 13 is obtained, the control unit 22 re-reads the radiation detection element 7s from which the saturated image data FA has been read out from the radiation detection element 7s by the re-reading process. The unread data value Dr is subtracted from the actually read image data Fb to calculate the lag data value Dl as the image data read again.

  At this time, it is determined how many unread data values Dr are included in the image data Fb actually read out by the re-reading process from the radiation detecting element 7s from which the saturated image data FA has been read out. It is not always easy to calculate directly from Fb itself. Therefore, in this embodiment, the unread data value for the radiation detection element 7s based on the unread data value Dr read from the radiation detection element 7 in the vicinity of the radiation detection element 7s from which the saturated image data FA has been read. Dr is calculated.

  In this embodiment, the unread data value Dr read from the nearby radiation detection element 7 is used as it is as the unread data value Dr for the radiation detection element 7s. It is also possible to perform a predetermined calculation process on the unread data value Dr read from the detection element 7 and calculate the unread data value Dr for the radiation detection element 7s.

  In this way, the calculated unread data value Dr is subtracted from the image data Fb actually read from the radiation detection element 7s in the re-reading process, and the lag data value as the re-read image data is obtained. Although Dl is calculated, for example, simply adding this lag data value Dl to the saturated image data FA read in the first reading process does not necessarily restore the image data FA.

  However, the lag data value Dl is considered to have some information for restoring the saturated image data FA, and the value to be added to the saturated image data FA read in the first reading process is the lag data value. It is considered that the larger the value of Dl, the larger the characteristic.

  Therefore, in the present embodiment, a feature amount C associated with the lag data value Dl is set in advance as a value to be added to the saturated image data FA read in the first reading process. In the present embodiment, the feature amount C is set as three types of values according to the size of the lag data value D1, as shown in FIG. 15, for example. It is also possible to set or classify into more types and to define it as a function of the lag data value Dl.

  And the control means 22 as a feature-value calculation means calculates | requires the feature-value C from the matching shown in FIG. 15 based on the calculated lag data value Dl. Then, the feature amount C is determined for each of the radiation detection elements 7s (see FIGS. 10 and 13) from which the saturated image data FA has been read in the first reading process.

  Subsequently, as shown in FIG. 16, the control unit 22 adds each calculated feature amount C to the corresponding saturated image data FA as a correction unit. Then, the above processing is performed for all the rows i (see FIG. 9A) of the radiation detection elements 7 arranged two-dimensionally in the detection unit P, or for each row i in the set range, and the calculated features. The amount C is added to the corresponding saturated image data FA.

  Then, the control unit 22 temporarily stores each saturated image data FA added with the feature amount C in the storage unit 23. Then, as described above (see the timing chart of FIG. 8 and the like), the control means 22 performs a reset process for each radiation detection element 7 and then performs a dark reading process to each radiation detection element 7. A dark reading value is acquired for each time, and an offset amount of the image data is calculated based on the dark reading value.

  Then, all the image data Fa including the saturated image data FA added with the feature amount C shown in FIG. 16 or the image data Fa including only the region Ro including the saturated image data FA added with the feature amount C, etc. The values obtained by subtracting the dark read values from the predetermined image data Fa are converted into non-saturated image data.

As a data conversion method at that time, for example, as shown in FIG. 17, the image data Fa is multiplied by a predetermined coefficient so that all the image data Fa ^* subjected to the data conversion are corrected to be less than the upper limit value 4095. Alternatively, for example, an LUT is created in advance, and the image data Fa is converted based on the LUT, and all the converted image data Fa ^* are corrected to be less than the upper limit value 4095. It is also possible to configure.

  As described above, according to the radiographic image capturing apparatus 1 according to the present embodiment, when the saturated image data FA exists in the image data Fa read in the first read process, the reset process is not performed. The readout process is performed again, the feature amount C is calculated based on the image data read again corresponding to the saturated image data FA, that is, the lag data value D1, and the feature amount C is added to the saturated image data FA. Then, it is corrected to the unsaturated image data.

  For this reason, the larger the data value (lag data value Dl) resulting from the lag in the re-reading process, utilizing the fact that the lag phenomenon occurs when the radiation is strong enough to saturate the image data FA. By associating a large feature amount C as if it was irradiated with intense radiation, the information on the subject O in the saturated image data FA part can be restored in a pseudo-realistic manner.

  For example, even if the radiation image capturing apparatus (FPD) 1 is irradiated with a high dose of radiation that mistakenly irradiates the CR apparatus and the saturated image data FA is partially captured, the saturated image is captured. It is possible to obtain a radiation image in which the information of the subject O in the data FA part is restored in a pseudo and accurate manner. Therefore, it is not necessary to perform re-imaging, and it is possible to prevent the burden on the patient and the exposure dose to the patient from increasing by performing the re-imaging.

[Radiation imaging system]
In the above embodiment, the control unit 22 of the radiographic image capturing apparatus 1 (portable radiographic image capturing apparatus 1) functions as a determination unit, a feature amount calculating unit, and a correcting unit. The case where it is configured to perform arithmetic processing has been described.

  However, when the radiographic image capturing apparatus 1 includes the battery 41 (see FIG. 7) as in the above-described embodiment, the radiographic image capturing apparatus 1 performs image data Fa and Fb read processing and dark read processing. If arithmetic processing such as feature amount calculation processing and correction processing is configured to be performed by an external device, power consumption of the battery 41 of the radiographic image capturing device 1 is suppressed correspondingly, and the battery 41 is charged per one charge. The number of times the radiographic image capturing apparatus 1 is used for radiographic image capturing can be increased, and the radiographic image capturing apparatus 1 can be used efficiently. Hereinafter, an embodiment of the radiographic imaging system configured as described above will be described.

  FIG. 18 is a diagram showing an overall configuration of the radiographic image capturing system according to the present embodiment. The radiographic imaging system 50 of this embodiment is a system that assumes radiographic imaging performed in, for example, a hospital or clinic, and can be employed as a system that captures medical diagnostic images as radiographic images.

  As shown in FIG. 18, the radiographic imaging system 50 includes, for example, an imaging room R1 that irradiates radiation and images a subject (part of the patient to be imaged) that is a part of a patient (not shown), and a radiographer or doctor. The operator is arranged in the anterior chamber R2 for performing various operations such as control of radiation applied to the subject and image processing of acquired radiographic images. The imaging room R1 is often shielded with lead or the like so that radiation does not leak outside.

  In the present embodiment, the radiographing room R1 includes a bucky device 51 that can be loaded with the above-described radiographic imaging device 1, a radiation generating device 52 that includes an X-ray tube (not shown) that generates radiation to be irradiated on the subject, and a radiographic image. A wireless access point (base station) 54 provided with a wireless antenna 53 that relays the communication when the photographing apparatus 1 and the console 58 perform wireless communication is provided.

  In the present embodiment, the wireless antenna 53 and the wireless access point 54 are communication means on the console 58 side that transmits and receives image data and the like with the radiation image capturing apparatus 1.

  In the anterior chamber R2, an operation console 56 for controlling radiation irradiation, which is provided with a switch means 55 for instructing the start of radiation irradiation from the radiation generating device 52, and a radiation image capturing apparatus 1 described later. A tag reader 57 that detects tags and a console 58 that controls the entire radiographic imaging system 50 are provided. The console 58 is connected to storage means 59 composed of a hard disk or the like.

  Although the configuration of the radiographic image capturing apparatus 1 is as described above, in the present embodiment, the radiographic image capturing apparatus 1 preferably further has the following configuration.

  Specifically, a tag (not shown) is incorporated in the radiation image capturing apparatus 1. In this embodiment, a tag called a so-called RFID (Radio Frequency IDentification) tag is used as the tag, and the tag stores a control circuit that controls each part of the tag and a storage that stores unique information of the radiographic imaging apparatus 1. The part is built in compactly. The unique information includes, for example, a cassette ID, scintillator type information, size information, resolution, and the like as identification information assigned to the radiation image capturing apparatus 1.

  Moreover, in this embodiment, the radiographic imaging device 1 is comprised by the dimension based on JISZ4905 (corresponding international standard is IEC 60406) in the cassette for conventional screens / films. That is, the thickness in the radiation incident direction is within a range of 15 mm + 1 mm to 15 mm-2 mm, and is 8 inches × 10 inches, 10 inches × 12 inches, 11 inches × 14 inches, 14 inches × 14 inches, 14 inches × 17 inches. (Half cut size) etc. are prepared.

  Thus, in this embodiment, since the radiographic imaging device 1 is formed in accordance with the JIS standard relating to the screen / film cassette, a CR cassette that is similarly formed in accordance with the JIS standard can be loaded. The radiographic imaging device 1 can be used by being mounted on a bucky device 51 for a CR cassette.

  In addition, this invention is not limited to the case where the radiographic imaging device 1 is formed in conformity with the JIS standard as described above, or the case where the bucky device 51 for CR cassette is used as the bucky device 51. However, if the bucky device 51 for CR cassette is used as the bucky device 51, it is possible to carry out radiographic imaging by loading both the radiographic imaging device 1 as FPD and the conventional CR cassette into the bucky device 51. It becomes.

  On the other hand, the radiographic image capturing apparatus 1 can be used in a so-called independent state that is not loaded in the bucky apparatus 51. That is, the radiographic image capturing apparatus 1 is disposed in a single state, for example, on a support stand provided in the radiographing room R1 or a bucky apparatus 51B for lying position imaging, and a subject is placed on the radiation incident surface R (see FIG. 1). The patient's hand or the like can be placed, or inserted between the patient's waist or legs lying on the bed and the bed, for example. In this case, for example, radiation image capturing is performed by irradiating the radiation image capturing apparatus 1 with radiation from the portable radiation generating apparatus 52B (see FIG. 18) or the like through the subject.

  The bucky device 51 is provided with a cassette holding portion 51a for holding the radiographic image capturing device 1 in a predetermined position, and the radiographic image capturing device 1 can be loaded into the cassette holding portion 51a. Further, in the present embodiment, as the bucky device 51, there are provided a bucky device 51A for standing position shooting and a bucky device 51B for standing position shooting.

  It should be noted that in the bucky device 51A for standing position photography and the bucky device 51B for standing position photography, for example, it is possible to appropriately adjust the position of the device itself or the height of the cassette holding portion 51a with respect to the bucky device body. It is the same as that of a known Bucky device.

  The imaging room R1 is provided with at least one radiation generating device 52 that includes an X-ray tube that irradiates the radiation imaging apparatus 1 with radiation via a subject. In the present embodiment, one radiation generating device 52A is shared by the bucky devices 51A and 51B for standing position shooting and lying position shooting. It should be noted that it is also possible to configure each of the bucky devices 51A and 51B in association with a separate radiation generating device.

  The radiation generating device 52A is arranged suspended from the ceiling of the photographing room R1, for example, and is set up based on an instruction from an operation console 56 (to be described later) at the time of photographing. It is moved to a position, and its direction is adjusted so that the radiation direction of the radiation faces a predetermined direction.

  In the present embodiment, a portable radiation generation device 52B that is not associated with the standing-up imaging device 51A and the standing-up imaging device 51B is also provided. It can be carried to any place in the photographing room R1, and can be irradiated with radiation in any direction.

  In the present embodiment, the portable radiation generation device 52B is also set up based on an instruction from the console 56. In addition to this, for example, an operator can manually set up, It is also possible to set up by transmitting a radio signal from the radiation imaging apparatus 1 to the portable radiation generation apparatus 52B.

  A radio antenna 53, which is a communication means on the console 58 side, relays these communications when the radiographic imaging apparatus 1 communicates with the console 58, the switch means 55, etc. in a corner of the imaging room R1. A wireless access point 54 is provided.

  FIG. 18 shows the case where the wireless access point 54 is provided near the entrance of the imaging room R1, but the present invention is not limited to this, and wireless communication with the antenna device 40 of the radiographic image capturing apparatus 1 is possible. It is installed at an appropriate position where possible. In the present embodiment, the wireless access point 54 is connected to each of the bucky devices 51A and 51B via a cable or the like, and communicates with the bucky devices 51A and 51B or the radiographic imaging device 1 loaded therein and the console 58 or the like. It can also be performed by a wired system.

  On the other hand, the front room R2 is provided with an operation console 56 provided with a switch means 55 for instructing the start of radiation irradiation from the radiation generator 52. The console 56 includes a computer having a general-purpose CPU (Central Processing Unit), a computer having a dedicated processor, or the like. In the present embodiment, the console 56 is connected to the switch means 55 and the radiation generator 52 and also to the console 58.

  In the present embodiment, the switch means 55 is provided with stroke detecting means 60 for detecting that a button part (not shown) of the switch means 55 is pressed by an operator such as a radiographer. Is pressed and a signal for instructing the start of radiation irradiation is transmitted from the console 56 to the radiation generating device 52, at the same time, the stroke detecting means 60 releases the button part of the switch means 55 and the pressing is released. This is detected, and a radiation irradiation start signal and an end signal are transmitted to the radiation image capturing apparatus 1 via the wireless access point 54.

  Therefore, with respect to the radiographic imaging apparatus 1 used in the radiographic imaging system 50 of the present embodiment, the radiation imaging apparatus 1 itself starts and ends radiation irradiation by providing the radiation sensor 35 as described above. There is no need to detect.

  In the vicinity of the entrance of the front chamber R2, a tag reader 57 for exchanging information with the radiographic imaging apparatus 1 using the RFID technology described above is installed. The tag reader 57 transmits predetermined instruction information on radio waves or the like via a built-in antenna (not shown), and detects the radiographic imaging apparatus 1 that enters or leaves the front room R2 or the imaging room R1. Yes. The tag reader 57 reads the unique information stored in the detected RFID tag of the radiographic imaging device 1 and transmits the read unique information to the console 58.

  The console 58 is composed of a computer in which a CPU, a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface and the like (not shown) are connected to the bus, and reads a predetermined program stored in the ROM. It expands in the work area of the RAM and executes various processes according to the program to control the entire radiographic imaging system 50 as described above.

  In FIG. 18, the case where the console 58 is installed outside the photographing room R1 or the front room R2 is described, but for example, the console 58 may be configured to be installed in the front room R2 or the like. It is.

  The console 58 is connected to the above-described console 56, tag reader 57, and the like, and is connected to the wireless access point 54 via the console 56 and the like. The console 58 is connected to a storage means 59 composed of an HDD (Hard Disk Drive) or the like. Further, the console 58 is provided with a display screen 58a made up of a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display) or the like, and other input means such as a keyboard and a mouse are connected thereto.

  When the console 58 receives the unique information including the cassette ID of the radiographic imaging apparatus 1 detected by the tag reader 57 as described above, the radiation existing in the imaging room R1 and the like registered in the storage unit 59 is transmitted to the console 58. A list of the image capturing device 1 is referred to. If the transmitted unique information is not registered in the storage means 59, the console 58 assumes that the radiographic imaging device 1 is newly brought into the radiographic room R1 or the front room R2, and the radiographic imaging thereof is performed. The cassette ID or the like of the device 1 is added to the above list and registered in the storage unit 59.

  If the transmitted unique information is already registered in the storage means 59, the radiographic image capturing apparatus 1 is assumed to have been taken out of the radiographing room R1 or the front room R2. Delete the cassette ID etc. from the above list. In this way, the console 58 grasps the radiation image photographing apparatus 1 brought into or taken out from the photographing room R1 or the like and manages it on the storage means 59.

  Also in the radiographic image capturing system 50 according to the present embodiment, as shown in the timing chart of FIG. 8, the control means 22 of the radiographic image capturing apparatus 1 is manually operated by the operator using the power switch 37 (see FIG. 1) or the like. When the operation or the signal transmitted from the console 58 is received via the antenna device 40, the radiation detection element 7 and the readout circuit 17 are reset.

  Then, the control means 22 detects the start and end of radiation irradiation based on the signal from the radiation sensor 35 and the signal transmitted from the stroke detection means 60, and when it is determined that radiographic imaging has been performed, as described above. The image data Fa is read from each radiation detection element 7 of the detection unit P, and each image data Fa is stored in the storage unit 23.

  Subsequently, as a determination unit, the control unit 22 analyzes the profile of each read image data Fa to determine whether or not the saturated image data FA exists in each image data Fa. If it is determined that the saturated image data FA does not exist in the region Ro described above, then, as shown in the timing chart of FIG. 8, after performing reset processing for each radiation detection element 7, dark reading processing is performed. Then, each dark reading value is stored in the storage means 23.

  On the other hand, if it is determined that the saturated image data FA is present in each image data Fa, the control means 22 reads the charge from each radiation detection element 7 again without performing the reset process for each radiation detection element 7 to read the image data. Read processing for conversion to Fb is performed, and each image data Fb is stored in the storage means 23. Then, after performing reset processing on each radiation detection element 7, dark reading processing is performed, and each dark reading value is stored in the storage unit 23.

  When the above-described series of processing ends, the control unit 22 transmits the image data Fa, the dark read value, and the image data Fb from the storage unit 23 from the antenna device 40 if the image data Fb is stored.

  When the console 58 receives the image data Fa or the like transmitted from the antenna device 40 of the radiographic imaging apparatus 1 via the wireless access point 54, the console 58 stores the data in the storage unit 59.

  When the data transmitted from the radiation image capturing apparatus 1 is only the image data Fa, that is, the image data Fa read by the first reading process and the dark reading value, the console 58 is dark as described above. Image processing for obtaining a radiographic image is performed by calculating an offset of each image data Fa from the read value and subtracting each offset from each image data Fa to calculate each true image data Fa.

  On the other hand, when the data transmitted from the radiation image capturing apparatus 1 is the image data Fa, the image data Fb read by the re-reading process, and the dark read value, the console 58 is the same as that of the above embodiment. As described above, the feature amount C is calculated based on the image data Fb corresponding to the saturated image data FA, and the offset calculated from the dark read value is subtracted from each saturated image data FA obtained by adding the calculated feature amounts C. After that, the image data is corrected to non-saturated image data by multiplying by a predetermined coefficient, for example. In this way, a radiographic image is obtained.

  As described above, according to the radiographic image capturing system 50 according to the present embodiment, the saturation image data is obtained by using the phenomenon that a lag phenomenon occurs when the radiation is so strong that the image data FA is saturated. The effect of the radiographic image capturing apparatus 1 according to the above-described embodiment, such that the information of the subject O in the FA portion can be restored in a pseudo-realistic manner, can be exhibited accurately.

  At the same time, since the radiographic imaging apparatus 1 does not perform arithmetic processing such as feature amount calculation processing and correction processing, the power consumption of the battery 41 of the radiographic imaging apparatus 1 can be reduced accordingly. Therefore, it is possible to increase the number of times the radiographic imaging apparatus 1 is used for radiographic imaging per charge of the battery 41, and the radiographic imaging apparatus 1 can be used efficiently.

  Needless to say, the present invention is not limited to the above-described embodiments and modifications, and can be changed as appropriate.

1 Radiographic imaging device (portable radiographic imaging device)
7 Radiation detection element 17 Reading circuit 22 Control means (determination means, feature amount calculation means, correction means)
40 Antenna device (communication means)
50 Radiographic imaging system 54 Wireless access point (communication means)
58 Console C Feature value Dr. Unread data value (unread portion of image data read out first)
Fa Image data Fa ^* Unsaturated image data FA Saturated image data Fb Re-read image data i Row O Subject P Detection unit Ro Area

Claims (10)

A detection unit in which a plurality of radiation detection elements that generate an electric charge according to a dose of radiation carrying information on a subject are arranged two-dimensionally;
A readout circuit that performs a readout process of reading out the charge from each radiation detection element and converting the charge into image data for each radiation detection element;
Determining means for analyzing the image data and determining whether there is saturated image data in which a data value is saturated;
When the determination means determines that the saturated image data exists, the read circuit is caused to perform the read process again without performing the reset process for each radiation detection element, and the saturated image data is handled. A feature amount calculating means for calculating a feature amount based on the image data read again,
Correction means for correcting each of the saturated image data to non-saturated image data based on each feature quantity calculated by the feature quantity calculation means,
A portable radiographic imaging device comprising:   The determination unit creates a data profile for each of the image data of each radiation detection element for each row or each column of the plurality of radiation detection elements arranged in a two-dimensional manner, and the subject is included in the data profile. 2. The image data in a region estimated to be image data of the radiation detecting element that has passed through transmitted radiation is analyzed to determine whether or not the saturated image data exists. The portable radiographic image capturing apparatus according to 1. The feature value is set in advance in the data value of the image data read again,
When the feature amount calculation unit causes the image data to be read again, the feature amount calculation unit assigns the feature amount to the re-read image data corresponding to the saturated image data,
The correction unit adds the feature amounts allocated by the feature amount calculation unit to the saturated image data, and adds to all or predetermined image data including the saturated image data to which the feature amount is added. The portable radiographic image capturing apparatus according to claim 1 or 2, wherein each of the images is corrected to unsaturated image data by multiplication by a predetermined coefficient.   The feature amount calculating means calculates a value obtained by subtracting an unread portion of the image data read out first from the image data actually read out in the re-reading process as the re-read image data. The portable radiographic imaging device according to any one of claims 1 to 3, wherein   The unread portion of the image data read out first is calculated from the unread portion of the image data read from the radiation detection element near the radiation detection element from which the saturated image data was read. The portable radiographic imaging device according to claim 4, wherein A detection unit in which a plurality of radiation detection elements that generate an electric charge according to a dose of radiation carrying information on a subject are arranged two-dimensionally;
A readout circuit that performs a readout process of reading out the charge from each radiation detection element and converting the charge into image data for each radiation detection element;
Determining means for analyzing the image data and determining whether there is saturated image data in which a data value is saturated;
Control means for causing the readout circuit to perform the readout process again without performing a reset process on each of the radiation detection elements when the judgment means determines that the saturated image data is present;
A communication means for transmitting / receiving data to / from an external device;
A portable radiographic imaging device comprising:
Communication means for transmitting and receiving data to and from the portable radiographic imaging device is provided, and the image data including the saturated image data and the image data read again are transmitted from the portable radiographic imaging device. And calculating feature values based on the read image data corresponding to the saturated image data, and correcting the saturated image data to unsaturated image data based on the calculated feature values. Console to
A radiographic imaging system comprising:   The determination unit of the portable radiographic imaging device creates a data profile for each image data of each radiation detection element for each row or each column of the plurality of radiation detection elements arranged in a two-dimensional manner, In the data profile, the image data in an area estimated to be image data of the radiation detecting element that has reached the radiation that has passed through the subject is analyzed to determine whether the saturated image data exists. The radiographic image capturing system according to claim 6. The feature value is set in advance in the data value of the image data read again,
The console assigns the feature amount to the image data read again corresponding to the saturated image data transmitted from the portable radiographic image capturing device, and assigns the feature amount to the assigned feature amount, The sum of each saturated image data is added, and all or predetermined image data including the saturated image data added with the feature amount is multiplied by a predetermined coefficient to be respectively corrected to unsaturated image data. The radiographic imaging system of Claim 6 or Claim 7.   The console reads out again a value obtained by subtracting the unread portion of the image data read out first from the image data actually read out in the re-reading process in the portable radiographic imaging device. The radiation image capturing system according to claim 6, wherein the radiation image capturing system is calculated as image data.   The unread portion of the image data read out first is calculated from the unread portion of the image data read from the radiation detection element near the radiation detection element from which the saturated image data was read. The radiographic image capturing system according to claim 9.

Images