JP2016146513A - Medical image system for diagnosis service - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image system for diagnosis service that can surely prevent occurrence of deterioration of image quality of a generated medical image for diagnosis service and makes a user impervious to such a feeling that a standby time for allowing irradiation of radiation ray in at least a second or subsequent imaging operation is long.SOLUTION: In a medical image system 50 for diagnosis service, control means 22 of FPD 1 continues a charge accumulation state for only an accumulation time τ for imaging. A notifying device 58 or the control means 22 of FPD 1 counts a time T after previous imaging is finished, and at the time point when the time T has elapsed by only a predetermined imaging interval δT, the notifying device 58 is made to notify that irradiation of radiation ray is possible. The predetermined imaging interval δT is set on the basis of the time interval obtained by subtracting the standby time WT1 set according to the accumulation time τ1 in the previous imaging operation and the time required for one imaging operation from the standby time WT2 set according to the accumulation time τ2 in a subsequent imaging operation in FPD 1.SELECTED DRAWING: Figure 17

Description

  The present invention relates to a medical image system for diagnosis providing that generates a medical image for diagnosis providing based on image data read out by a radiographic imaging device.

  In the field of X-ray photography, the shift from the conventional silver salt photography method using screens / films to CR (computed radiography) cassettes using photostimulable phosphor sheets, etc. has enabled digitization from analog photography methods. It is illustrated. In recent years, a radiation image capturing device (Flat Panel Detector, hereinafter) in which radiation detection elements that generate charges (electron-hole pairs) in response to radiation irradiated from a radiation generator and transmitted through a subject are arranged in a two-dimensional manner. Various types of FPDs) have been developed and are used for taking medical images for diagnosis provision in medical sites such as hospitals.

  In recent years, a portable FPD in which a sensor panel or the like on which a radiation detection element or the like is formed is housed in a casing and can be carried has been developed and put into practical use (for example, see Patent Document 1).

  In such an FPD, for example, as shown in FIG. 2 and the like to be described later, usually, a plurality of radiation detection elements 7 are arranged in a two-dimensional form (matrix) on the detection unit P4 of the sensor panel SP, and each radiation detection element is detected. A switch element formed by a thin film transistor (hereinafter referred to as TFT) 8 is connected to each element 7.

  When imaging is performed by irradiating the FPD with radiation from the radiation generator through the subject, all the TFTs 8 are turned off for a predetermined time and generated in each radiation detection element 7 by radiation irradiation. The charged charges are accumulated in each radiation detection element 7.

  Hereinafter, the “predetermined time” set for accumulating charges in each radiation detection element 7 is referred to as an accumulation time τ. A state in which all TFTs 8 are turned off and charges are accumulated in each radiation detection element 7 is referred to as a charge accumulation state. That is, the accumulation time τ means the duration of this charge accumulation state.

  Then, after the accumulation time τ elapses, reading processing of the image data D from each radiation detection element 7 is performed. In the readout process, an ON voltage is sequentially applied from the gate driver 15b to each of the lines L1 to Lx of the scanning line 5 so that each TFT 8 is sequentially turned on, and is generated and accumulated in each radiation detection element 7 by radiation irradiation. The charges are sequentially discharged to the signal lines 6 and read out as image data D by the readout circuits 17, respectively.

  By the way, as described above, in order to accurately accumulate the charges generated by the irradiation of radiation in each of the radiation detection elements 7, at the same time as the irradiation of the radiation to the FPD is started from the radiation generating apparatus, or Before starting, it is necessary that each TFT 8 which is a switching element of the FPD is in an OFF state.

  As one method for realizing this, for example, there is a case where imaging is performed while synchronizing between the radiation generation apparatus and the FPD. Such a photographing method is hereinafter referred to as a synchronous method.

  In the case of this synchronization method, for example, the FPD receives a wake-up signal (also referred to as a wake-up signal or the like) from a console 58 (see FIGS. 3 and 4 described later) or an exposure described later from the radiation generator. When a signal indicating that the first-stage operation of the shooting switch 56 (ie, a so-called half-pressing operation) has been received, etc., reset processing of each radiation detection element 7 for removing the charge remaining in each radiation detection element 7 To start.

  When the reset processing of each radiation detection element 7 is performed, for example, as shown in the left part of FIG. 19, an ON voltage is applied to each line L1 to Lx of the scanning line 5 from the gate driver 15b (see FIG. 2 described later). It may be configured to be applied sequentially, and although not shown, it may be configured to apply the ON voltage to the lines L1 to Lx of the scanning line 5 from the gate driver 15b all at once. Is possible. Further, Tac in FIG. 19 will be described later.

  When an operator such as a radiologist operates the second stage of the exposure switch 56 (that is, a so-called full pressing operation), an irradiation start signal is transmitted from the radiation generating apparatus to the FPD. Then, when the FPD receives the irradiation start signal, as shown in FIG. 19, the reset processing of each radiation detection element 7 is ended, and an interlock release signal is transmitted to the radiation generation apparatus. And a radiation generator irradiates radiation at the time of receiving an interlock release signal.

  Further, when the reset process of each radiation detection element 7 is finished, the FPD transmits the interlock release signal as described above, and at the same time, turns off the TFT 8 and shifts to the charge accumulation state. Then, radiation is irradiated during the accumulation time τ. In addition, the shaded portion in FIG. 19 represents a period during which radiation is emitted from the radiation generation apparatus.

  Then, after the accumulation time τ elapses, the FPD sequentially applies on-voltages to the lines L1 to Lx of the scanning line 5 from the gate driver 15b as described above, so that the image data D from each radiation detection element 7 is transferred. It is configured to perform a read process.

  On the other hand, when the manufacturers of the FPD and the radiation generation apparatus are different from each other, it may not be possible to construct an interface between them. Such an imaging method performed without synchronizing the FPD and the radiation generating apparatus is hereinafter referred to as an asynchronous method.

  Also in this asynchronous system, it is necessary to turn off each TFT 8 that is a switching element of the FPD when radiation irradiation to the FPD is started from the radiation generating device. For this reason, when imaging is performed in an asynchronous manner, normally, the FPD itself detects that radiation has been emitted without exchanging signals with the radiation generator.

  To realize this, for example, as described in Patent Document 2, when X-ray detection means detects the start of radiation irradiation by attaching an X-ray detection means such as an X-ray sensor to the FPD. In addition, it is possible to configure so that the reset process of each radiation detection element 7 is stopped and the charge accumulation state is entered.

  Note that Patent Document 2 discloses a case in which an X-ray detection unit such as an X-ray sensor is provided on the side of the FPD with respect to the radiation irradiation direction. On the other hand, it may be configured to be provided at the center of the back side (downstream side) of the FPD.

  Further, instead of attaching an X-ray sensor or the like to the FPD as described above, for example, as described in Patent Document 3, predetermined radiation among the radiation detection elements 7 arranged in a two-dimensional manner as described above. It is also possible to configure the detection element 7 to be used as a sensor.

  Further, as described in, for example, Patent Document 4, it is possible to provide a current detection means on a bias line 9 (see FIG. 2 and the like described later) connected to each radiation detection element 7. . In this case, when the FPD is irradiated with radiation, electric charge is generated in each radiation detection element 7 and the current flowing through the bias line 9 increases. Therefore, it is possible to detect the start of radiation irradiation based on the current value detected by the current detection means.

  Further, as described in Patent Document 5 and the like, a state in which each TFT 8 is turned off by applying an off voltage to all the scanning lines 5 from the gate driver 15b of the scanning driving means 15 before the start of radiation irradiation. It is also possible to configure the readout circuit 17 to perform a readout operation, and to perform a readout process of the leak data dleak that reads out the charges leaked from the radiation detection element 7 as the leak data dleak through the TFT 8.

  Furthermore, as described in Patent Document 6 and the like, it is also possible to perform a configuration in which image data reading processing is performed before the start of radiation irradiation. In this case, the image data read out in this case is referred to as image data d for irradiation start detection, in distinction from the image data D as the main image read out after photographing as described above.

  If the inventions described in Patent Documents 5 and 6 are employed, when radiation irradiation to the FPD is started, the values of the leak data dleak read out as described above and the image data d for irradiation start detection are as follows: It becomes much larger than before the start of irradiation. For this reason, it is possible to detect the start of radiation irradiation when, for example, the read leak data dleak or image data d for detection of irradiation start is equal to or greater than a threshold value.

  Even if any of the above detection methods in the asynchronous method is employed, when the FPD detects the start of irradiation of radiation from the radiation generator, all the TFTs 8 are turned off and the charge accumulation state is entered. Then, after the accumulation time τ elapses, the image data D is read from each radiation detection element 7 as described above.

JP-A-6-342099 JP 2007-151761 A JP 2011-174908 A JP 2009-219538 A International Publication No. 2011/13517 Pamphlet International Publication No. 2011-152093 Pamphlet

  By the way, in each radiation detection element 7, so-called dark charges (also referred to as dark current) are constantly generated by thermal excitation or the like due to heat (temperature) of the radiation detection element 7 itself. For this reason, when the TFT 8 serving as the switch element is turned off, the dark charge continues to accumulate in the radiation detection element 7.

  Then, for example, when the reading process of the image data D as the main image is performed according to the processing sequence as shown in FIG. 19, the on-voltage is applied during the reset process before the reading process, and then the reading of the image data D is performed. Until the on-voltage is applied during processing, the TFT 8 is in an off state, and thus dark charges generated in each radiation detection element 7 during that time are accumulated in each radiation detection element 7.

Therefore, in the image data D read out by the reading process, as described above, the data resulting from the charge generated by the irradiation of radiation (that is, the so-called true image data D ^* ) is superimposed with the offset o due to the dark charge. It has become.

  More precisely, the image data D has a voltage applied in the read process of the image data D after the voltage applied in the reset process before the read process is switched from the on voltage to the off voltage. An offset o due to dark charges generated in each radiation detection element 7 is superimposed during a time Tac (hereinafter, this time Tac is referred to as an effective accumulation time Tac) until switching from the on voltage to the off voltage.

That is, between the image data D, the true image data D ^*, and the offset o due to the dark charge,
D = D ^* + o (1)
The relationship is established.

  Then, the offset data O reading process for reading the offset o due to the dark charge as offset data O (also referred to as a dark read value or the like) is usually performed after photographing. The amount of dark charge accumulated in each radiation detection element 7, that is, the offset o due to the dark charge superimposed on the image data D changes according to the length of the effective accumulation time Tac. Further, if the length of the effective accumulation time Tac is the same, the value of the offset o due to the dark charge is the same.

  Therefore, in the offset data O reading process, the effective accumulation time Tac for each of the lines L1 to Lx of the scanning line 5 is set to the same time interval as the effective accumulation time Tac (see FIG. 19) in the image data D reading process. The offset data O and the offset o due to the dark charge superimposed on the image data D can be made the same size.

In this case, since O = o, if this is substituted into the above equation (1) and transformed,
D ^* = D-o
= DO (2)
Thus, by subtracting the offset data O read by the offset data O reading process from the image data D read by the image data D reading process, each radiation detecting element 7 is irradiated with radiation. It is possible to easily and accurately calculate true image data D ^* resulting from only the generated charges.

  In order to realize this, as described above, it is necessary to set the effective accumulation time Tac in the reading process of the offset data O to the same time interval as the effective accumulation time Tac in the reading process of the image data D. Become.

  Therefore, as shown in FIG. 20, for example, the offset data O reading process is often configured to repeat the same processing sequence as the processing sequence up to the image data D reading process shown in FIG. By configuring so that the same processing sequence is repeated in this way, the timing of applying the ON voltage to each of the lines L1 to Lx of the scanning line 5 is the case of the reading process of the image data D and the case of the reading process of the offset data O The effective accumulation time Tac becomes the same time interval for each of the lines L1 to Lx of the scanning line 5.

  Note that the reading process of the offset data O is naturally performed in a state where the FPD is not irradiated with radiation. At that time, transmission of an interlock release signal to the radiation generator 55 is not performed. In this case, the accumulation time τ (see FIG. 19), which is the duration of the charge accumulation state before the image data D reading process, and the accumulation time τ before the offset data O reading process (see FIG. 20) are also completely different. Set to the same time interval.

In this way, if the offset data O is read out by repeating the same processing sequence as the processing sequence up to the reading processing of the image data D (see FIG. 19), the reading processing of the image data D is performed. The effective accumulation time Tac and the effective accumulation time Tac at the time of the reading process of the offset data O are the same time interval, and the offset o due to the dark charge superimposed on the image data D and the offset data O have the same size. . Therefore, when the image processing is performed, the offset amount o due to the dark charge superimposed on the image data D and the offset data O are canceled by performing the calculation of the above equation (2), so that the true image data D ^* Can be calculated accurately.

However, in theory, it should be as described above, but actually, the offset data O is read out as described above, and the read offset data O and image data D are substituted into the above equation (2). It has been found that when the image data D ^* is calculated, the offset o due to the dark charge superimposed on the image data D and the offset data O may not be offset.

In such a situation, the reading process of the image data D and the reading process of the offset data O are performed as described above, and a true image is obtained according to the above equation (2) based on the read image data D and the offset data O. When the data D ^* is calculated, the image quality of the diagnostic-provided medical image generated based on the calculated true image data D ^* may be deteriorated.

  As a result of the inventors' researches on the cause of the phenomenon as described above, in particular, the FPD has a photographing mode including at least a control unit 22, a scanning drive unit 15, and a readout IC 16 ( (See FIG. 2 to be described later) etc.) A power is supplied to each functional unit such as a wake up mode in which imaging can be performed, and power is supplied only to necessary functional units such as the communication unit 30 to perform imaging. It has been found that the above phenomenon appears when it is configured to be able to transition to a sleep mode that cannot be performed.

  The present invention has been made in view of the above problems, and even when imaging is performed using an FPD that can change the imaging mode of the radiographic imaging apparatus (FPD) from the sleep mode to the awakening mode, It is an object of the present invention to provide a diagnostic providing medical image system capable of accurately preventing deterioration of the image quality of a generated diagnostic providing medical image.

  In addition, in the present invention, as will be described later, attention is paid to the duration of charge accumulation state described above, that is, the accumulation time τ at the time of imaging, and radiation irradiation after the FPD imaging mode is changed from the sleep mode to the awakening mode. The above-mentioned object is achieved by increasing the waiting time until the image is allowed (see “WT” in FIG. 10 and the like described later) as the shooting in which the accumulation time τ in the shooting becomes longer.

  Therefore, when imaging with a long accumulation time τ is performed, the waiting time becomes long, and an operator such as a radiographer irradiates the radiation from the radiation generating apparatus after changing the FPD imaging mode from the sleep mode to the awakening mode. It may happen that it takes a long time for the

  Therefore, according to the present invention, at least in the second and subsequent imaging, an operator such as a radiographer changes the imaging mode of the radiographic imaging device (FPD) from the sleep mode to the awakening mode and then emits radiation from the radiation generator. It is another object of the present invention to provide a medical image system for providing diagnosis capable of preventing a long time until irradiation is allowed.

In order to solve the above problems, the medical image system for providing diagnosis according to the present invention comprises:
A plurality of scanning lines and a plurality of signal lines;
A plurality of radiation detection elements arranged two-dimensionally;
A switch element connected to each of the scanning lines, and discharging a charge accumulated in the radiation detection element to the signal line when an on-voltage is applied;
A bias power source for applying a reverse bias voltage to each of the radiation detection elements;
A panel portion having
Scanning drive means for switching a voltage applied to each scanning line between an on-voltage and an off-voltage,
A readout circuit for reading out the electric charge emitted to the signal line as image data;
Control means for controlling at least the scanning drive means and the readout circuit to perform the readout processing of the image data;
A radiographic imaging device comprising:
A radiation generator for irradiating the radiation imaging apparatus with radiation through a subject; and
A notification device;
With
The radiographic image capturing apparatus supplies an imaging mode, an awakening mode capable of performing imaging by supplying power to each functional unit including at least the control unit, and supplying power only to necessary functional units to perform imaging. Is configured to be able to transition between sleep modes that cannot be performed,
The control means of the radiographic imaging apparatus applies reset voltage to the scanning lines from the scanning driving means after performing reset processing of the radiation detecting elements during imaging. The charge accumulation state in which charges generated in each radiation detection element due to radiation irradiation in the off state are accumulated in each radiation detection element is continued for a set accumulation time, and then at least the scanning drive Controlling the means and the readout circuit to perform the readout processing of the image data,
The control unit of the notification device or the radiographic imaging device counts the time since the previous imaging was completed in the radiographic imaging device, and when the time has passed a predetermined imaging interval, The notification device is configured to notify that it is possible to perform imaging by irradiating radiation from the radiation generation device,
The predetermined imaging interval ranges from a waiting time set according to the accumulation time at the time of subsequent imaging in the radiographic imaging device to a waiting time set according to the accumulation time at the previous imaging and once It is set based on a time interval obtained by subtracting the time required for shooting.

  According to the medical image system for diagnosis providing of the system as in the present invention, the FPD imaging mode is changed from the sleep mode to the awakening mode, the imaging is performed in a short time, the image data D is read out by the FPD, and the offset is continued. Even when data O is read out, the diagnosis is generated based on the read image data D and offset data O by appropriately switching the waiting time according to the set accumulation time. It is possible to accurately prevent the deterioration of the image quality of the medical image.

  In at least the second and subsequent imaging, a time until an operator such as a radiologist is allowed to irradiate radiation from the radiation generator after the FPD imaging mode is changed from the sleep mode to the awakening mode. Therefore, it is possible to make the diagnosis providing medical image system convenient for the operator.

It is a perspective view which shows the external appearance of FPD. It is a block diagram showing the equivalent circuit of FPD. It is a figure which shows the structural example of the medical image system for diagnosis provision constructed | assembled in the imaging | photography room etc. It is a figure showing the structural example of the medical image system for diagnosis provision constructed | assembled on the round-trip vehicle, and the portable terminal which an operator carries. It is a timing chart explaining the timing etc. which apply an ON voltage to each scanning line, when detecting the irradiation start of radiation based on leak data. 6 is a timing chart showing that offset data reading processing is performed by repeating the processing sequence shown in FIG. 5. It is a graph showing an example of the state which the electric charge amount per unit time which generate | occur | produces in a radiation detection element reduces gradually as time passes. FIG. 8 is a graph for explaining that an offset amount o and offset data O due to dark charges superimposed on image data D in the example of FIG. 7 are respectively expressed as areas of hatched areas. FIG. 8 is a graph for explaining that the amount of charge per unit time generated in each radiation detection element becomes a constant value and the offset amount o and the offset data O become equal after the time has elapsed in the example of FIG. 7. It is a timing chart explaining transmitting a signal to an alarm device etc. when the elapsed time after changing to a wake-up mode passes only waiting time. FIG. 8 is a graph for explaining a difference Δ between an offset amount o due to dark charges superimposed on image data D and offset data O in the example of FIG. FIG. 12 is a graph for explaining that the difference Δ becomes larger than the case of FIG. 11 when the effective accumulation time Tac becomes longer in the example of FIG. 7. 13 is a graph for explaining that the difference Δ is reduced by increasing the waiting time in the case of FIG. 12. It is a figure showing an example of the screen displayed on the display part of a console. It is a figure showing an example of the screen comprised so that the accumulation | storage time can be set simultaneously with setting an imaging | photography site | part and an imaging | photography direction. It is a figure showing an example of the screen at the time of comprising so that accumulation time can be set on the screen shown in FIG. It is a timing chart in an example in which the first shooting is performed after a short waiting time has elapsed since the transition to the awakening mode, and then the second shooting is performed after a long waiting time has elapsed. It is a graph explaining that the voltage Vb applied to each radiation detection element from a bias power supply changes so that it may approach 0 [V] gradually from the time of the transition to an awakening mode. 6 is a timing chart for explaining the timing of applying an ON voltage to each scanning line when shooting is performed in a synchronous manner. 20 is a timing chart showing that offset data read processing is performed by repeating the processing sequence shown in FIG. 19.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a medical image system for diagnosis provision according to the present invention will be described with reference to the drawings.

  In the following, the radiographic imaging device is also referred to as FPD. In the following, a so-called indirect FPD that includes a scintillator or the like as an FPD used in a medical image system for diagnosis provision and obtains image data by converting emitted radiation into electromagnetic waves of other wavelengths such as visible light. As will be described, the present invention can also be applied to a so-called direct FPD in which radiation is directly detected by a radiation detection element without using a scintillator or the like.

  Although the case where the FPD is a so-called portable type will be described, the present invention can also be applied to a so-called dedicated type FPD formed integrally with a support base or the like.

[About FPD]
Here, before explaining the medical image system for diagnosis provision according to the present invention, the FPD 1 used in the medical image system for diagnosis provision will be described. FIG. 1 is a perspective view showing the appearance of the FPD.

  In the present embodiment, the FPD 1 is configured by housing a sensor panel (not shown) in a casing 2 formed of a carbon plate or the like. On one side surface of the housing 2, a power switch 25, a changeover switch 26, a connector 27, an indicator 28, and the like are arranged. Although not shown, in the present embodiment, an antenna device 29 (see FIG. 2 to be described later) for performing wireless communication with the outside is provided on, for example, the opposite side surface of the housing 2.

  Note that the FPD 1 uses the antenna device 29 when communicating with the outside in a wireless manner, and communicates by connecting a cable (not shown) to the connector 27 when communicating with the outside in a wired manner. It has become.

  Further, in this embodiment, the FPD 1 can be loaded with a conventional screen / film cassette or a CR device cassette, and a later-described Bucky device 51 (see FIG. 3 described later) already installed in a facility such as a hospital. In order to be able to be loaded, the size conforming to the JIS standard size (JISZ 4905) in the cassette for the screen / film is formed.

  That is, at least the thickness dimension in the radiation incident direction of the housing 2 (that is, the direction orthogonal to the extending direction of the radiation incident surface R of the housing 2 (see FIG. 1)) is within the dimension range of 13 to 16 mm. Is formed. The size of the FPD 1 is formed in various sizes from a commercially available minimum size of 10 × 12 inches to a maximum size of 17 × 17 inches. In addition, this invention is applied also to FPD which is not formed in the size based on such a JIS specification size.

  FIG. 2 is a block diagram showing an equivalent circuit of the FPD. As shown in FIG. 2, in the FPD 1, a plurality of radiation detection elements 7 are arranged in a two-dimensional shape (matrix shape) on a sensor substrate (not shown). Each of the radiation detection elements 7 generates charges in accordance with radiation irradiated from a radiation source 52 (see FIGS. 3 and 4) of a radiation generator 55 (described later) and transmitted through a subject (not shown).

  Each radiation detection element 7 is connected to a bias line 9, and the bias line 9 is connected to a bias power supply 14 through a connection 10. A reverse bias voltage is applied from the bias power source 14 to each radiation detection element 7 via the bias line 9 and the like. Each radiation detection element 7 is connected to a thin film transistor (hereinafter referred to as TFT) 8 as a switching element, and the TFT 8 is connected to the signal line 6.

  In the scanning drive means 15, an ON voltage and an OFF voltage are supplied from the power supply circuit 15a to the gate driver 15b via the wiring 15c, and applied to the lines L1 to Lx of the scanning line 5 by the gate driver 15b. The voltage is switched between an on voltage and an off voltage.

  Each TFT 8 is turned on when an on-voltage is applied via the scanning line 5, and the radiation detection element 7 and the signal line 6 are brought into conduction, and the charge in the radiation detection element 7 is read out. . Further, each TFT 8 is turned off when an off voltage is applied via the scanning line 5, and the conduction between the radiation detection element 7 and the signal line 6 is cut off.

  The control means 22 is a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface, etc., not shown, connected to the bus, an FPGA (Field Programmable Gate Array), or the like. It is configured. It may be configured by a dedicated control circuit.

  The control means 22 is connected to a storage means 23 composed of SRAM (Static RAM), SDRAM (Synchronous DRAM) or the like, and performs an antenna device 29 for wireless communication with the outside or wired communication. A communication unit 30 to which a connector 27 is connected is connected. Further, a battery 24 that supplies necessary power to each functional unit such as the scanning drive unit 15, the readout circuit 17, the storage unit 23, and the bias power supply 14 is connected to the control unit 22.

  In the reading process of the image data D, the control unit 22 sequentially applies on-voltages to the lines L1 to Lx of the scanning line 5 from the gate driver 15b (see FIG. 2), for example, as shown in FIG. Each TFT 8 connected to the scanning line 5 is turned on.

  When each TFT 8 is turned on, each radiation detection element 7 and each signal line 6 are electrically connected, and the electric charge discharged from each radiation detection element 7 to the signal line 6 is read out in each readout IC 16. Read by the circuit 17. Specifically, a voltage value is output from the amplification circuit 17 in accordance with the amount of charge that has flowed from the radiation detection element 7 into the amplification circuit 18 of the readout circuit 17.

  Then, the correlated double sampling circuit (described as “CDS” in FIG. 2) 19 converts the difference between the voltage values output from the amplifier circuit 18 before and after the charge flows from each radiation detection element 7 into an analog value. The image data D is output downstream. The output image data D is sequentially transmitted to the A / D converter 20 via the analog multiplexer 21, and is sequentially converted into digital image data D by the A / D converter 20, and is output to the storage means 23. Are stored sequentially.

  In the present embodiment, the FPD 1 can perform shooting by supplying power to at least the functional units such as the reading IC 16 including the control unit 22, the scanning drive unit 15, and the reading circuit 17 in the shooting mode. A wake up mode (also referred to as a shootable mode) and a sleep mode in which power is supplied only to necessary functional units such as the communication unit 30 that communicates with the outside, and imaging cannot be performed. Can be transitioned between.

  The FPD 1 may be configured such that, for example, the shooting mode is set to the awakening mode when the power switch 25 is turned on, and the shooting mode is set to the sleep mode when the power switch 25 is turned on. It may be configured. Further, for example, when a wake-up signal is received from a console 58 (described later, see FIGS. 3 and 4), the photographing mode is changed from the sleep mode to the wake-up mode.

  In the present embodiment, the FPD 1 changes the shooting mode to the sleep mode when the shooting mode is changed to the awakening mode and no shooting is performed even after a predetermined time has elapsed.

  Each process performed at the time of shooting with the FPD 1 and each process performed thereafter will be described in detail later.

[Medical imaging system for diagnosis provision]
Next, the configuration and the like of the diagnostic providing medical image system 50 according to the present embodiment will be described. FIG. 3 is a diagram illustrating a configuration example of the medical image system 50 for providing diagnosis according to the present embodiment. FIG. 3 shows a case where the diagnostic providing medical image system 50 is constructed in the imaging room R1 or the like.

  A bucky device 51 is installed in the photographing room R1, and the bucky device 51 can be used by loading the FPD 1 in a cassette holding portion (also referred to as a cassette holder) 51a. FIG. 3 shows a case where a bucky device 51A for standing position shooting and a bucky device 51B for standing position shooting are installed as the bucky device 51. For example, only one of the bucky devices 51 is provided. It may be done.

  As shown in FIG. 3, at least one radiation source 52 </ b> A of the radiation generator 55 that irradiates the FPD 1 loaded in the Bucky device 51 via the subject is provided in the imaging room R <b> 1. In the present embodiment, by moving the position of the radiation source 52A or changing the irradiation direction of the radiation, radiation is applied to both the standing-up imaging device 51A and the standing-up imaging device 51B. Can be done.

  The photographing room R1 is provided with a repeater 54 for relaying communication between the devices in the photographing room R1 and the devices outside the photographing room R1. In the present embodiment, the repeater 54 is provided with an access point 53 so that the FPD 1 can transmit and receive image data D, signals, and the like in a wireless manner.

  The repeater 54 is connected to the radiation generator 55 and the console 58. The relay 54 is connected to the local area network (LAN) communication signal transmitted from the FPD 1, the console 58, etc. to the radiation generator 55. Is converted into a signal or the like for the radiation generator 55, and vice versa.

  In the present embodiment, the front room (also referred to as an operation room) R2 is provided with an operation console 57 of the radiation generating device 55. The operation panel 57 is operated by an operator such as a radiation engineer. An exposure switch 56 is provided for instructing the generator 55 to start radiation irradiation.

  The exposure switch 56 is provided with a button (not shown). As described above, when an operator such as a radiologist performs the first-stage operation (that is, so-called half-press operation) on the button of the exposure switch 56, the radiation generator 55 activates the radiation source 52. To be ready for radiation.

  Then, when the operator performs the second-stage operation (that is, so-called full-press operation) on the button of the exposure switch 56, the radiation generator 55 starts from the FPD 1 in the synchronous method as described above. When the interlock release signal is transmitted, the radiation source 52 emits radiation.

  Further, when imaging is performed in an asynchronous manner, the radiation generator 55 irradiates the radiation from the radiation source 52 when the operator performs the second stage operation on the exposure switch 56.

  The radiation generator 55 performs various controls such as setting a tube current and an irradiation time for the radiation source 52 so that an appropriate dose of radiation is emitted from the radiation source 52. .

  As shown in FIG. 3, in the present embodiment, a console 58 formed of a computer or the like is provided in the front chamber R2. The console 58 can be configured to be provided outside the imaging room R1 and the front room R2, in a separate room, and the like, and is installed in an appropriate place.

  Further, the console 58 is provided with a display unit 58a configured to include a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display), and the like, and also includes input means such as a mouse and a keyboard (not shown). Yes. In addition, the console 58 is connected to or has a built-in storage means 59 composed of an HDD (Hard Disk Drive) or the like.

  Although not shown, the console 58 is connected to the console 58 via a network such as a LAN, HIS (Hospital Information System), RIS (Radiology Information System), PACS (Picture Archiving and Communication). System) etc. are connected.

  On the other hand, as shown in FIG. 4, the FPD 1 is not loaded in the bucky device 51, but can be used in a so-called state. FIG. 4 is a diagram illustrating a configuration example of the diagnostic providing medical image system 50 constructed on the round-trip wheel 60.

  For example, when the patient H cannot get up from the bed B of the patient room R3 and cannot go to the radiographing room R1 as shown in FIG. 3, the FPD 1 and the round-trip car 60 are moved to the patient room R3 as shown in FIG. It can be brought in and inserted between the bed B and the body of the patient H or applied to the body of the patient H.

  Further, when the FPD 1 is used in the hospital room R3 or the like, the radiation generator 55 is mounted on the round-trip wheel 60 and installed in the hospital room R3 as shown in FIG. 4 instead of the radiation generator 55 installed in the imaging room R1 described above. Brought in. Further, in this case, the roundabout wheel 60 is equipped with a portable radiation 52P that can appropriately change the radiation direction and the like.

  The roundabout wheel 60 is also equipped with a console 58 and the like. Although not shown in FIG. 4, the roundabout wheel 60 is configured to include the access point 53, the repeater 54, and the like shown in FIG. 3.

  The same applies to the case where the photographing is performed in the photographing room R1 shown in FIG. 3. For example, as shown in FIG. 4, the operator E such as a radiologist carries the portable terminal 70 having the display unit 71 and the console. The image displayed on the 58 display units 58 a can also be configured to be displayed on the display unit 71 of the mobile terminal 70.

  If comprised in this way, it will become possible for operators, such as a radiographer, to confirm an image on the display part 71 of the portable terminal 70 which he carries, without going to the console 58 one by one. Therefore, it is convenient for the operator.

[Regarding normal processing during shooting]
Next, normal processing of the FPD 1 control means 22 and console 58 during shooting will be described.

  For example, when an instruction is input by an operator such as a radiologist before imaging, the console 58 transmits an awakening signal to the FPD 1 used for imaging, and changes the imaging mode of the FPD 1 to the awakening mode. When the imaging mode is changed to the awakening mode, the FPD 1 starts a reset process for each radiation detection element 7 that removes the charge remaining in each radiation detection element 7 as a pre-process for imaging.

  Then, when the operator such as a radiologist completes positioning of the FPD 1 and the patient H as the subject, the operator moves to the exposure switch 56 of the radiation generator 55 and operates the exposure switch 56 to generate radiation. Radiation is emitted from the radiation source 52 of the device 55.

  When imaging is performed in a synchronous manner, when the second-stage operation of the exposure switch 56 (that is, a so-called full-press operation) is performed, as described above, irradiation from the radiation generator 55 to the FPD 1 is performed. A start signal is transmitted. Then, as shown in FIG. 19, an interlock release signal is transmitted to the radiation generation device 55 from the FPD 1 that has completed the reset processing of each radiation detection element 7. And the radiation generator 55 irradiates radiation at the time of receiving the interlock release signal.

  Further, as shown in FIG. 19, the FPD 1 transmits the interlock release signal as described above, and at the same time, the TFT 8 is turned off to shift to the charge accumulation state. Then, radiation is irradiated during the accumulation time τ. Then, after the accumulation time τ has elapsed, the FPD 1 sequentially applies on-voltages to the lines L1 to Lx of the scanning line 5 from the gate driver 15b, and performs a process of reading the image data D from each radiation detection element 7. Configured as follows.

  When imaging is performed in an asynchronous manner, the FPD 1 resets each radiation detection element 7 as imaging pre-processing as described above when the imaging mode is changed to the awakening mode as described above. After performing the above, as described above, in order to detect the start of the radiation irradiation by itself, it is configured to perform a radiation irradiation start detection process.

  For example, as described in Patent Document 5 described above, the leak data dleak is read before radiation irradiation, and the radiation irradiation start is detected based on the read leak data dleak. Is possible.

  In addition, when reading the leak data dleak, as described above, the off-voltage is applied to all the scanning lines 5 from the gate driver 15b (see FIG. 2) of the FPD 1 so that each TFT 8 is turned off. Leak data dleak is read by performing a read operation.

  However, if the TFTs 8 are kept in the OFF state, dark charges are continuously accumulated in the respective radiation detection elements 7 as described above. Therefore, as shown on the left side of FIG. The dleak read process (see “L” in FIG. 5) and the reset process of each radiation detection element 7 (see “R” in FIG. 5) are alternately performed.

  When an operator such as a radiologist operates the exposure switch 56 to irradiate radiation from the radiation source 52P as described above, the FPD 1 sets, for example, the leak data dleak read in a certain read process. The start of radiation irradiation is detected when the threshold value is exceeded (see “Detection” in FIG. 5).

  Then, when the start of radiation irradiation is detected in this way, the control means 22 of the FPD 1 applies an off voltage to each scanning line 5 from the gate driver 15b, and keeps all the TFTs 8 for a predetermined time, that is, the accumulation time τ described above. In the meantime, the electric charge generated in each radiation detection element 7 by irradiation of radiation is accumulated in each radiation detection element 7.

  As in the case of the synchronous method, after the accumulation time τ elapses, the image data D is read out from each radiation detection element 7.

  In FIG. 5, in order to make the effective accumulation time Tac in each of the lines L1 to Lx of the scanning line 5 the same time, in the reading process of the image data D, the time when the start of radiation irradiation is detected or From the scanning line 5 to which the ON voltage is to be applied next (the line L5 of the scanning line 5 in the case of FIG. 5) to the scanning line 5 to which the ON voltage is applied immediately before (the line L4 of the scanning line 5 in the case of FIG. 5). The case where the application of the on-voltage is started and the readout process is performed by sequentially applying the on-voltage to each of the lines L5 to Lx and L1 to L4 of the scanning line 5 from the gate driver 15b is shown.

  However, for example, as shown in FIG. 19, the application of the on-voltage is started from the first line L1 of the scanning line 5, and the on-voltage is sequentially applied to the lines L1 to Lx of the scanning line 5 from the gate driver 15b for reading. It is also possible to configure to perform processing.

  Further, when the image data D is read out as described above, for example, the control means 22 of the FPD 1 extracts the preview image data Dp from the read image data D and transmits it to the console 58. In 58, the preview image p_pre may be generated based on the preview image data Dp or the like and displayed on the display unit 58a or the display unit 71 of the mobile terminal 70.

  On the other hand, when the control means 22 of the FPD 1 completes the reading process of the image data D (see FIGS. 5 and 19) as described above, the control means 22 performs the offset data O reading process as shown in FIGS. The reset process of each radiation detection element 7 is started.

  Then, as described above, in order to set the effective accumulation time Tac (see FIG. 5) for each scanning line 5 to the same time interval between the reading process of the image data D and the reading process of the offset data O, FIG. As shown in FIG. 20 and FIG. 20, the same processing sequence as the processing up to the reading process of the image data D shown in FIG. 5 and FIG. 19 is repeated, and the reading process of the offset data O is performed.

  When the control unit 22 of the FPD 1 performs the offset data O reading process as described above, the read image data D and the offset data O are transmitted to the console 58 (see FIGS. 3 and 4).

The console 58 calculates true image data D ^* according to the above equation (2) based on the transmitted image data D and offset data O, and performs gain correction and defective pixels based on the true image data D ^*. The medical image p for diagnosis provision is generated by performing precise image processing such as correction and gradation processing according to the imaging region.

  When the generated diagnostic providing medical image p is approved by an operator such as a radiographer, the console 58 determines the generated diagnostic providing medical image p, and information on the confirmed diagnostic providing medical image p is displayed. Etc. are configured to be transmitted to a necessary location such as the PACS described above.

[Phenomenon that can occur in normal processing]
As shown in FIG. 6 and FIG. 20, if the offset data O read process is configured to repeat the same process sequence as the process sequence up to the image data D read process (see FIG. 5 and FIG. 19). In the image processing, by performing the calculation of the above equation (2) as described above, the offset o due to the dark charge superimposed on the image data D and the offset data O are offset, and the true image data D ^* should be calculated accurately.

However, actually, as described above, even if the true image data D ^* is calculated as described above, the offset o due to the dark charge superimposed on the image data D and the offset data O are not offset. There is a case. When the diagnosis providing medical image p is generated based on the true image data D ^* calculated in a state where the offset o due to the dark charge and the offset data O are not canceled out, the image quality of the generated diagnosis providing medical image p May deteriorate.

  As a result of repeated researches on the cause of the occurrence of such a phenomenon by the present inventors, in particular, as described above, immediately after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode, the imaging and reading of the offset data O are performed. It has been found that the above phenomenon appears when done.

  The major cause of such a phenomenon is that the charge amount dQ per unit time generated in the radiation detection element 7 immediately after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode as follows. It is thought to be a major change.

  For example, when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode, as shown in FIG. 7, it occurs in the radiation detection element 7 at the time of the transition to the awakening mode (see the time point t = 0 in FIG. 7). The charge amount dQ per unit time becomes a large value, and from this point, the charge amount dQ per unit time generated in the radiation detection element 7 gradually decreases as time t elapses.

FIG. 7 is a graph showing the relationship between the elapsed time t from when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode and the charge amount dQ per unit time generated in each radiation detection element 7. It is. Note that FIG. 7 does not include charges generated in each radiation detection element 7 by irradiation of radiation (that is, charges corresponding to true image data D ^* (see the above equation (1))).

  Further, as time t elapses, the amount of charge dQ per unit time generated in each radiation detection element 7 gradually decreases, and finally becomes constant equal to the amount of dark charge generated per unit time described above. Settling down in value.

  In such a situation, as shown in FIG. 5 and FIG. 19, reset processing of each radiation detection element 7 before imaging is performed (in the case of FIG. 5, leak data dleak reading processing is performed alternately with reset processing). ) Each TFT 8 is turned off to be in a charge accumulation state (radiation is irradiated during this period), and after the accumulation time τ has elapsed, the reading process of the image data D is performed.

  Then, after the image data D reading process, as shown in FIG. 6 and FIG. 20, the same processing sequence as the image data D reading process shown in FIG. 5 and FIG. O reading processing is performed.

  In this case, the offset amount o due to the dark charge superimposed on the image data D and the offset data O are respectively during the effective accumulation time Tac (see FIGS. 5 and 19) before the reading processing of the image data D, and Calculated as an integral value of the charge amount dQ (see FIG. 7) per unit time generated in each radiation detection element 7 during the effective accumulation time Tac (see FIGS. 6 and 20) before the offset data O reading process. Is done.

  Therefore, the offset o due to the dark charge superimposed on the image data D and the offset data O are values represented as the area of the region indicated by hatching, as shown in FIG.

  After a lapse of time after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode, the charge amount dQ per unit time generated in each radiation detection element 7 is reduced as described above, and the above-described Since the constant value is equal to the amount of dark charge generated per unit time, the offset amount o and the offset data O due to the dark charge superimposed on the image data D are equal to each other as shown in FIG.

Therefore, as described above, when the calculation process for subtracting the offset data O from the image data D is performed as shown in the above equation (2), the offset o and offset data due to the dark charge superimposed on the image data D are obtained. It is possible to calculate true image data D ^* resulting from only the electric charges generated in each radiation detection element 7 due to irradiation with the radiation offset by O.

Therefore, in normal image processing, as described above, the medical image p for diagnosis provision is generated based on the true image data D ^* calculated by subtracting the offset data O from the image data D according to the above equation (2). Configured to be.

  However, as shown in FIG. 8, immediately after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode, the charge amount dQ per unit time generated in each radiation detection element 7 increases as the time t elapses. It is in a state of decreasing. Therefore, when the reading process of the image data D and the reading process of the offset data O are performed as described above in this state, the offset o due to the dark charge superimposed on the image data D is displayed as shown in FIG. Is larger than the offset data O.

That is, if the difference between the offset o due to the dark charge superimposed on the image data D and the offset data O is Δ, the offset o due to the dark charge superimposed on the image data D and the offset data O In between
o = O + Δ (3)
However, in the case of FIG. 8, that is, in a state immediately after the photographing mode of the FPD 1 is changed from the sleep mode to the awakening mode, the difference Δ takes a positive value that is not zero.

And D ^* = D−o (4) obtained by modifying the above equation (1)
If the above equation (3) is substituted,
D ^* = D−O−Δ (5)
Is obtained.

This and the above equation (2), that is,
D ^* = DO (2)
As can be seen from the above, when the offset data O is subtracted from the image data D according to the above equation (2) in the image processing for generating the medical image p for providing diagnosis, the true image data D ^* calculated is calculated ^. is a large value only original true image data D ^* that is, the equation (4) (i.e., (5)) true image data to be calculated by D ^* difference Δ than.

That is, when the true image data D ^* is calculated according to the above equation (2) as in normal image processing, the calculated true image data D ^* is the above equation (4) (ie, the equation (5). ), The original true image data D ^* to be calculated is a value in which the offset due to the dark charge is superimposed by the difference Δ.

  As described above, when the reading process of the image data D or the reading process of the offset data O is performed immediately after the photographing mode of the FPD 1 is changed from the sleep mode to the awakening mode (see FIG. 8), the image data D is superimposed on the image data D. A positive difference Δ significantly different from 0 is generated between the offset o due to the dark charge and the offset data O.

Then, during the subsequent image processing, (2) calculating the true image data D ^* in accordance with equation was calculated true image data D ^*, i.e. dark charge true that should not contain any offset by The image data D ^* has a value in which the offset due to the dark charge is superimposed by the difference Δ.

Therefore, when the diagnostic-providing medical image p is generated based on such true image data D ^* , the image quality of the generated diagnostic-providing medical image p is dark charge by a difference Δ from the true image data D ^*. Therefore, the amount of offset due to the superimposition deteriorates.

[About switching the waiting time according to the accumulation time]
Next, one characteristic aspect of the medical image system for diagnosis providing 50 according to the present embodiment will be described.

  As described above, in the state immediately after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode, the amount of charge dQ per unit time generated in each radiation detection element 7 changes with time. A non-zero positive difference Δ between the offset o and the offset data O due to the dark charge superimposed on D causes the image quality of the generated diagnostic-provided medical image p to deteriorate. ing.

  As the difference Δ increases, the degree of deterioration of the image quality of the generated diagnostic providing medical image p increases. Conversely, if the difference Δ decreases, the generated diagnostic providing use If the degree of deterioration of the image quality of the medical image p is reduced and the difference Δ is made sufficiently small, it is possible to prevent the image quality of the generated medical image p for diagnosis providing from being deteriorated.

  That is, as shown in FIG. 9, the offset o and offset data due to the dark charge superimposed on the image data D after a sufficient amount of time has elapsed since the shooting mode of the FPD 1 was changed from the sleep mode to the awakening mode. When the medical image p for diagnosis providing is generated based on the image data D and the offset data O read out in a state equal to O, the high quality diagnostic providing medical image p is generated. If it can be made smaller, it is possible to generate a medical image p for diagnosis providing with a picture quality as high as this.

  Therefore, in the diagnostic providing medical image system 50 according to the present embodiment, a predetermined time (hereinafter, this time is referred to as a waiting time WT) has elapsed since the imaging mode of the FPD 1 was changed from the sleep mode to the awakening mode. Shooting is allowed after the difference Δ is sufficiently small.

  Specifically, in the present embodiment, as shown in FIG. 10, the control means 22 of the FPD 1 counts the elapsed time t after the shooting mode is changed from the sleep mode to the awake mode, and the elapsed time t is When the waiting time WT of elapses, a signal is transmitted to the notification device. The notification device is configured to notify an operator such as a radiologist that radiation can be emitted from the radiation generation device 55 when receiving the above signal from the FPD 1. Yes.

  In the present embodiment, the console 58 (see FIG. 3 and FIG. 4) functions as the above notification device. When the console 58 (hereinafter referred to as the notification device 58) as the notification device receives the above signal from the FPD 1, for example, the console 58 displays a message such as “I can shoot” on the display unit 58a, or utters a voice. For example, it can be configured to notify that it is possible to perform imaging by irradiating radiation from the radiation generating device 55.

  Further, as the notification device, for example, the portable terminal 70 shown in FIG. 4 may be used, and the notification device may be configured as a separate device from the console 58. In addition, a plurality of devices including the console 58 can be configured to function as a notification device.

  As described above, the “detection process” in FIG. 10 is as described above after the FPD 1 transitions to the awake mode and performs the reset process of each radiation detection element 7 when imaging is performed in an asynchronous manner. This represents a transition to detection processing of the start of irradiation with various radiations.

  In addition, when the imaging is performed in a synchronous manner, the reset process of each radiation detection element 7 is repeatedly performed after the FPD 1 transitions to the awakening mode. For example, a predetermined number of times for power saving or the like. It is also possible to configure such that the reset process is temporarily stopped after the reset process is performed and the reset process is restarted before the waiting time WT elapses.

  If comprised as mentioned above, the control means 22 of FPD1 will transmit a signal to the alerting | reporting apparatus 58, and only the said waiting time WT will pass after imaging | photography mode is changed from sleep mode to awakening mode, and the alerting | reporting apparatus 58 However, it is notified that it is possible to perform imaging by irradiating radiation from the radiation generating device 55. Then, an operator such as a radiologist who has confirmed the notification by the notification device 58 operates the exposure switch 56 to irradiate radiation from the radiation generation device 55 and performs imaging.

  Therefore, as shown in FIG. 11, the offset o due to the dark charge superimposed on the image data D read out in this way, and the offset read out in the subsequent read-out process It is possible to make the difference Δ with the data O sufficiently small. Then, by reducing the difference Δ, the degree of deterioration of the image quality of the diagnostic providing medical image p generated by the subsequent image processing is sufficiently reduced, and the generated diagnostic providing medical image p is actually reduced. It is possible to prevent the image quality from deteriorating.

  In other words, in the waiting time WT, the difference Δ is sufficiently small, and the diagnostic providing medical image p generated based on the read image data D and offset data O is the same as the waiting time WT. The time is set such that the image quality is practically invisible.

  On the other hand, the difference Δ, that is, the difference Δ between the offset o due to the dark charge superimposed on the image data D and the offset data O increases as the effective accumulation time Tac (see FIGS. 5 and 19) changes. Changes.

  Therefore, as shown in FIG. 12, for example, the notification device 58 can take a picture when the same waiting time WT as the waiting time WT shown in FIG. 11 has elapsed after the shooting mode of the FPD 1 is changed from the sleep mode to the awakening mode. Even if it is notified that, as shown in FIG. 12, if the effective accumulation time Tac becomes longer, the difference Δ becomes larger than the case shown in FIG. Therefore, if the diagnostic providing medical image p is generated based on the image data D and the offset data O read in such a state, the image quality of the diagnostic providing medical image p may be deteriorated.

  That is, in order not to deteriorate the image quality of the medical image p for diagnosis providing, it is necessary to change the waiting time WT according to the effective accumulation time Tac. That is, when the effective accumulation time Tac is long, it is necessary to lengthen the waiting time WT as shown in FIG. 13, for example, in order to sufficiently reduce the difference Δ.

  As described above, when the FPD 1 is configured such that the irradiation of radiation to the FPD 1 is allowed after the waiting time WT has elapsed since the imaging mode of the FPD 1 has been changed from the sleep mode to the awakening mode, the image on the FPD 1 It is necessary to switch the waiting time WT according to the effective accumulation time Tac in the data D reading process or the offset data O reading process.

  Therefore, the waiting time WT is set to be different according to the effective accumulation time Tac in the FPD 1, and the waiting time WT is switched according to the set effective accumulation time Tac. Yes.

  However, in actual control in the FPD 1, the effective storage time Tac is often set by the storage time τ (see FIGS. 5 and 19) that is the duration of the charge storage state.

  That is, for example, in the case of the synchronization method shown in FIG. 19, the timing for sequentially applying the ON voltage to each scanning line 5 in the reset processing of each radiation detecting element 7 before the charge accumulation state (that is, applying the ON voltage to a certain scanning line 5 The time interval from the application to the application of the ON voltage to the next scanning line 5 (the same applies hereinafter) is determined in advance.

  In addition, the timing at which the ON voltage is sequentially applied to each scanning line 5 in the reading process of the image data D performed after the charge accumulation state is also determined in advance. Therefore, if the accumulation time τ is set, the effective accumulation time Tac is automatically determined.

  Also, for example, in the case of the asynchronous method shown in FIG. 5, the on-voltage is sequentially applied to each scanning line 5 in the reset processing of each radiation detection element 7 that is alternately performed with the reading processing of the leak data dleak before the charge accumulation state. The application timing is determined in advance.

  In addition, the timing at which the ON voltage is sequentially applied to each scanning line 5 in the reading process of the image data D performed after the charge accumulation state is also determined in advance. Therefore, even in the case of the asynchronous method, the effective accumulation time Tac is automatically determined by setting the accumulation time τ. Thus, setting the accumulation time τ is synonymous with determining the length of the effective accumulation time Tac. In this embodiment, as described above, in the actual control in the FPD 1, the accumulation time τ is set to The effective accumulation time Tac is determined by setting.

  Therefore, in the present embodiment, the waiting time WT is set to a different time according to the accumulation time τ in the FPD 1. Specifically, as shown in FIG. 11 and FIG. The waiting time WT is set so that the waiting time WT becomes longer as the set accumulation time τ (that is, the effective accumulation time Tac) is longer. The waiting time WT is switched according to the set accumulation time τ.

  It should be noted that the accumulation time τ can be set at any time interval, and what waiting time WT is associated with each set accumulation time τ is the performance of the FPD 1, that is, FIG. The charge amount dQ per unit time generated in the radiation detection element 7 shown in FIG.

  Further, for example, when the radiation source 52 of the radiation generating device 55 irradiates radiation, the dose rate of the irradiated radiation (that is, the dose per unit time) instantaneously rises to a prescribed dose rate, and when the irradiation ends. In some cases, there is an irradiation characteristic such that the dose rate of irradiated radiation falls instantaneously.

  In the case of such a radiation source 52, it is not necessary to set the accumulation time τ to a time longer than necessary. For example, when the radiation source 52 emits radiation, the dose rate of the irradiated radiation is It may take a long time to rise slowly and reach a prescribed dose rate, and may have an irradiation characteristic that the dose rate of the irradiated radiation gradually falls at the end of irradiation. In such a case, it is necessary to set the accumulation time τ to be long so as not to waste the radiation emitted from the radiation source 52.

  In this way, the accumulation time τ can be set at any time interval, and what waiting time WT is associated with each set accumulation time τ is determined by irradiating the FPD 1 with radiation. It can also vary depending on the irradiation characteristics of the radiation source 52 of the radiation generator 55.

  Further, depending on the imaging region of the patient as the subject, the imaging method for the subject, and the like, it may be necessary to perform imaging by irradiating the radiation from the radiation generating device 55 for a longer time than usual. Therefore, when imaging is performed with such an imaging region or imaging method, it is necessary to set the accumulation time τ to be long.

  Therefore, based on the specifications of the FPD 1, the specifications of the diagnostic providing medical image system 50 in which the FPD 1 is used, the imaging conditions including the imaging region and the imaging method, etc., the settable accumulation time τ and each accumulation time τ The length of the waiting time WT associated with each is determined in advance as appropriate.

  In this case, the accumulation time τ can be set as a discrete time interval, or can be set as a time interval that can be continuously changed. For example, when the accumulation time τ is set as a time interval that can be continuously changed, the waiting time WT may be set in advance as a function of the accumulation time τ.

[effect]
As described above, according to the diagnostic providing medical image system 50 according to the present embodiment, the waiting time WT is set in advance according to the accumulation time τ as described above. The waiting time WT is configured to be switched according to the accumulation time τ.

  At that time, the waiting time WT is a time from when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode until irradiation of the radiation to the FPD 1 is permitted. When shooting is performed with irradiation, the difference Δ between the offset o due to the dark charge superimposed on the image data D and the offset data O becomes sufficiently small, and based on such image data D and offset data O. The time is set so that the image quality of the medical image p for diagnosis providing generated in this way can be prevented from deteriorating.

  Then, when the imaging mode is changed from the sleep mode to the awakening mode, for example, by receiving an awakening signal from the console 58, the control means 22 of the FPD 1 counts an elapsed time t after the transition to the awakening mode. Then, when the elapsed time t has elapsed by the waiting time WT, a signal is transmitted to the notification device 58 (console 58 in the present embodiment), and the notification device 58 notifies the operator such as a radiologist to the radiation generation device 55. It is informed that it is possible to shoot with radiation.

  Then, an operator such as a radiologist who has confirmed the notification by the notification device 58 operates the exposure switch 56 to irradiate the FPD 1 with radiation from the radiation source 52 of the radiation generation device 55 through the subject to perform imaging.

  Therefore, when the operator irradiates the FPD 1 with radiation through the subject, imaging is performed in this way, the image data D is read out, and then the processing sequence until the reading processing of the image data D is repeated to offset. When the data O is read to read the offset data O, and the medical image p for diagnosis providing is generated based on the read image data D or the offset data O, the offset o due to the dark charge superimposed on the image data D is generated. And the offset data O are sufficiently small, the deterioration of the image quality of the generated diagnostic-provided medical image p is accurately prevented.

  In the present embodiment, in this way, after the shooting mode of the FPD 1 is changed from the sleep mode to the awakening mode, shooting is performed in a short time, the image data D is read by the FPD 1, and the offset data O reading process is subsequently performed. Even in this case, it is possible to accurately prevent the image quality of the medical image p for diagnosis providing generated based on the image data D and the offset data O read out in this way from being deteriorated. .

[How to set storage time etc. in FPD]
Next, how to set the accumulation time τ in the FPD 1 will be described.

  In the present embodiment, as described above, for example, as illustrated in FIG. 6, the offset data O reading process repeats the same processing sequence up to the image data D reading process illustrated in FIG. 5. Done. Therefore, the accumulation time τ is set to the same time interval in the charge accumulation state before the image data D reading process (see FIG. 5) and the charge accumulation state before the offset data O reading process (see FIG. 6).

  Therefore, in this embodiment, by setting the accumulation time τ (see FIGS. 5 and 19) in the charge accumulation state before the reading process of the image data D, the charge accumulation before the offset data O reading process is automatically performed. The accumulation time τ (see FIG. 6 and FIG. 20) in the state is set.

  As a method of setting the accumulation time τ to the FPD 1, for example, an operator such as a radiographer can input the accumulation time τ to the console 58 and transmit it from the console 58 to the FPD 1 to set it. It is.

  In this case, for example, a screen H1 as shown in FIG. 14 is displayed on the display unit 58a of the console 58. A display space S in which a preview image p_pre generated by the console 58, a medical image p for diagnosis provision, and the like are displayed is provided at the center of the screen H1, and the console 58 has an RIS or the like on the left side of the screen H1. An icon I corresponding to the imaging order information selected by the operator such as a radiographer from the imaging order information obtained from the above is displayed. FIG. 14 shows a state in which a plurality of icons I corresponding to each imaging order information regarding the patient A are displayed side by side in the vertical direction.

  Further, below the screen H1, for example, a button icon or the like for instructing to display a plurality of medical images p for diagnosis providing by frame advance or frame return is displayed. Further, on the right side of the screen H1, A button icon BI or the like for designating the size of the FPD 1 to be used or designating how to display the preview image p_pre or the medical image p for diagnosis provision on the display space S is displayed. .

  For example, when a predetermined icon on the screen H1 is clicked or a mouse is right-clicked on the screen H1, a screen H2 as shown in FIG. 15 is displayed on the display unit 58a of the console 58. It has become. Note that the user can return to the screen H1 shown in FIG. 14 by clicking a predetermined icon on the screen H2 or by right-clicking the mouse on the screen H2.

  For example, on the screen H <b> 2, “AP (front)”, “PA (back)”, “LAT (side)”, etc. are taken with respect to an imaging region such as “Chest” or “Abdomen”. The direction can be specified. In the example shown in FIG. 15, for each imaging direction of each imaging region, either a normal accumulation time τ such as 1 second or a long accumulation time τ such as 10 seconds can be set. .

  In the example shown in FIG. 15, the button icon BI without “LONG” is a button icon for setting the normal accumulation time τ simultaneously with the imaging region and imaging direction, and “LONG” is added. The button icon BI is a button icon for setting an accumulation time τ of a longer time simultaneously with an imaging region and an imaging direction.

Further, as described above, instead of switching from the screen H1 (see FIG. 14) to the screen H2 (see FIG. 15) and setting the accumulation time τ, as shown in FIG. 16, for example, a button icon shown on the right side of the screen H1 Each button icon BI ^* representing a normal accumulation time τ and a long accumulation time τ may be displayed in the BI group or the like, and the accumulation time τ may be set on the screen H1.

  Further, in the examples shown in FIG. 15 and FIG. 16, a case is shown in which only one of a normal accumulation time and a longer accumulation time can be set as the accumulation time τ. However, when the button icons BI to be displayed are further increased to increase the number of accumulation times τ that can be set to three or more, or as described above, the accumulation time τ is set as a time interval that can be continuously changed. Can be configured such that an operator such as a radiologist inputs and sets the accumulation time τ on the screen H1 or the screen H2 using a keyboard or the like.

  Although not shown in the drawings, an operator such as a radiographer can be configured by displaying information on the set accumulation time τ on the display space S in the center of the screen H1 shown in FIGS. Is preferable because it is possible to easily check the length of the set accumulation time τ by looking at the display space S of the screen H1.

  Further, as described above, the waiting time WT elapses after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode, and a signal is transmitted from the FPD 1 to the console 58 that is a notification device. To notify the operator that radiation can be performed from the radiation generation device 55, for example, as described above, on the display space S of the screen H1 "can be photographed." It is possible to make a notification such as by displaying “

  Also, until the above-described waiting time WT elapses, for example, “Starting” or “Preparing” is displayed on the display space S of the screen H1, and the FPD 1 is starting or preparing. It is also possible to configure so as to notify an operator such as a radiologist that the imaging is not yet possible.

  As described above, when the accumulation time τ is set, the console 58 is configured to transmit and set information on the set accumulation time τ to the FPD 1.

  At that time, if the wake-up signal is not yet transmitted to the FPD 1, the console 58 transmits the wake-up signal to the FPD 1 as described above to change the photographing mode of the FPD 1 from the sleep mode to the wake-up mode. It is possible to configure the storage time τ to be transmitted to the FPD 1.

  If the wake-up signal is already transmitted to the FPD 1, the console 58 transmits the information on the accumulation time τ set to the FPD 1 when the accumulation time τ is set as described above. Configured to set.

  When configured as described above, the FPD 1 is configured in advance to include a table that associates the accumulation time τ and the waiting time WT, a function that associates the waiting time WT as a function of the accumulation time τ, and the like. .

  When the wake-up signal is received and the photographing mode of the FPD 1 is changed from the sleep mode to the wake-up mode, the control means 22 of the FPD 1 starts counting the elapsed time t. Further, the control means 22 of the FPD 1 calculates the waiting time WT from the above table, function, etc. based on the information of the accumulation time τ obtained from the console 58.

  A signal is transmitted to the notification device 58 when the elapsed time t has elapsed by the determined waiting time WT. When an operator such as a radiologist operates the exposure switch 56 to irradiate the radiation generating device 55 with radiation, the control means 22 of the FPD 1 stores the accumulated time τ transmitted from the console 58. Only the charge accumulation state is continued, and the image data D is read or the offset data O is read.

  In this way, by configuring the console 58 to transmit the information on the accumulation time τ to the FPD 1, it is possible to accurately exhibit the beneficial effects in the above embodiment.

  As described above, instead of configuring the console 58 to transmit the storage time τ information to the FPD 1, it is possible to configure the console 58 to transmit the waiting time WT information to the FPD 1.

  In the case of such a configuration, for example, the console 58 is input by an operator such as a radiographer or specified in the imaging order information obtained from the RIS or the like. The waiting time WT is determined based on information such as the generation device 55 and the imaging conditions such as the imaging region and imaging method, and the information of the determined waiting time WT is transmitted to the FPD 1 and set.

  Then, when information on the waiting time WT is transmitted from the console 58, the control means 22 of the FPD 1 calculates the accumulation time τ from a table or function (or its inverse function) provided in advance based on the information. Thus, even if it is configured to transmit the waiting time WT information from the console 58 to the FPD 1, it is possible to accurately exhibit the beneficial effects described above in the present embodiment.

[Configurations Specific to the Present Invention]
By the way, based on the above configuration, the diagnostic providing medical image system 50 according to the present embodiment is configured as follows. The operation of the medical image system for diagnosis providing 50 according to the present invention will also be described.

  In the diagnostic providing medical image system 50 configured as described above, for example, as shown in FIG. 17, the first time immediately after the short waiting time WT1 has elapsed since the imaging mode of the FPD 1 was changed from the sleep mode to the awakening mode. Let us consider a case in which the second shooting is performed under the long accumulation time τ2 after the long waiting time WT2 elapses.

  In FIG. 17, “D” is a process for reading image data D, “O” is a process for reading offset data O, and “R” is a reset process for each radiation detection element 7 (in the case of the asynchronous method, radiation irradiation start is performed). Including detection processing). Further, δT in FIG. 17 will be described later.

In such a case, as shown in FIG. 17, at the time t ^* when the reading process of the image data D is performed in the first shooting and the reading process of the offset data O is subsequently performed, the second process is still performed. There is a case where the long waiting time WT2 corresponding to the long accumulation time τ2 in photographing has not elapsed.

  As described above, after the shooting mode of the FPD 1 is changed from the sleep mode to the awakening mode, when the second and subsequent shootings are performed following the first shooting, the shooting mode is changed from the sleep mode in the second and subsequent shootings. If the elapsed time t since the transition to the wake-up mode has not elapsed by the waiting time WT2 that is switched according to the accumulation time τ2 in the second and subsequent imaging, the control means 22 of the FPD 1 As shown in FIG. 17, the signal is transmitted to the notification device 58 when the waiting time WT2 for the second and subsequent shootings has elapsed as shown in FIG. 58 is informed that shooting is possible.

  Therefore, the diagnosis providing medical image system 50 according to the present invention is configured as follows by further extending this point.

That is, as described above, the control means 22 (see FIG. 2) of the FPD 1 does not have to be configured to count the elapsed time t after the shooting mode is changed from the sleep mode to the awakening mode, or in parallel therewith. The FPD 1 is configured to count the time T from the end of the previous shooting (see time t ^{* in} FIG. 17), and this time T is only a predetermined shooting interval δT as shown in FIG. When the time has elapsed, a signal is transmitted to the notification device 58.

  When the notification device 58 receives the above signal from the FPD 1, the notification device 58 notifies the operator such as a radiologist that radiation can be emitted from the radiation generation device 55 as in the above case. Configured to do.

  In the case of FIG. 17, the predetermined shooting interval δT is changed from the waiting time WT2 set according to the storage time τ2 at the time of subsequent shooting in the FPD 1 as described above to the storage time τ1 at the time of previous shooting. Is set as a time interval obtained by subtracting the waiting time WT1 set in accordance with and the time required for one shooting. As shown in FIG. 17, the time required for one imaging is the accumulation time τ, the time required for the reading process of the image data D (see D in the figure), and the radiation detecting element 7 after the reading process. The time required for the reset process (see R in the figure), the accumulation time τ before the offset data O reading process, and the time required for the offset data O reading process (see O in the figure). .

Further, the notification device 58 itself can be configured to count the time T described above. In this case, when the notification device 58 receives a signal from the FPD 1 indicating that photographing has been completed (not shown in FIG. 17; see time t ^{* in} FIG. 17), the notification device 58 starts counting time T from that point in time. Is configured to notify that it is possible to perform imaging by irradiating radiation from the radiation generating device 55 when a predetermined imaging interval δT has elapsed.

[effect]
With this configuration, in the diagnostic providing medical image system 50 configured as described above, when imaging with a long accumulation time τ is performed, an operator such as a radiologist wakes up the imaging mode of the FPD 1 from the sleep mode. After transition to the mode, it is necessary to wait for a long waiting time WT such as 1 minute until radiation irradiation is allowed. However, as shown in FIG. When short imaging is performed, after the imaging with a short accumulation time τ1, the radiation time is irradiated after waiting for a shorter imaging interval δT without waiting for a long time such as 1 minute as described above, and the accumulation time τ2 It is possible to perform long shooting. That is, it is possible to set a shorter time until irradiation with radiation is allowed in the second imaging than in the first imaging.

  Therefore, the operator does not have to feel that it takes a long time until radiation is permitted from the radiation generating device 55, and the diagnostic providing medical image system 50 is easy to use for the operator. It becomes possible.

  Further, even if the diagnosis providing medical image system 50 adopts the configuration unique to the present invention, as described above, the waiting time WT is originally switched according to the accumulation time τ. Therefore, as described above, even when the FPD 1 performs imaging with a long accumulation time τ, it is possible to accurately prevent deterioration in the image quality of the generated diagnostic providing medical image.

  Note that FIG. 17 shows a case where the accumulation time τ1 of the previous photographing is short and the accumulation time τ2 of the subsequent photographing is long, but the present invention has a long accumulation time τ1 of the previous photographing and the accumulation of the subsequent photographing. The present invention can also be applied when the time τ2 is short, when the previous shooting accumulation time τ1 and the subsequent shooting accumulation time τ2 are both short, and when the previous shooting accumulation time τ1 and the subsequent shooting accumulation time τ2 are both long. it can.

  In the above three cases other than the case where the previous shooting accumulation time τ1 shown in FIG. 17 is short and the subsequent shooting accumulation time τ2 is long, as described above, the predetermined shooting interval δT is set to the FPD1. A time interval obtained by subtracting the waiting time WT1 set according to the accumulation time τ1 at the previous shooting and the time required for one shooting from the waiting time WT2 set according to the accumulation time τ2 at the subsequent shooting. When calculated, the calculated shooting interval becomes a negative value.

  For this reason, in such a case, 0 is set as the predetermined shooting interval δT. That is, in this case, the control means 22 and the notification device 58 of the FPD 1 can immediately perform shooting by irradiating the notification device 58 with radiation from the radiation generating device 55 when the previous shooting is completed in the FPD 1. This will be notified.

[Configuration for Reducing Charge Quantity dQ per Unit Time Generated in Radiation Detecting Element 7]
By the way, the reason why the waiting time WT is switched according to the accumulation time τ in the medical image system for diagnosis providing 50 according to the present embodiment is that the imaging mode of the FPD 1 is changed from the sleep mode as shown in FIG. At the time of transition to the awakening mode (see the time t = 0 in FIG. 7), the charge amount dQ per unit time generated in the radiation detection element 7 becomes a large value, and as time t elapses from there. This is because the charge amount dQ per unit time generated in the radiation detection element 7 gradually decreases.

  Therefore, if the charge amount dQ per unit time generated in the radiation detection element 7 can be further reduced, the waiting time WT set according to the accumulation time τ can be further shortened.

  As a result of repeated studies by the present inventors, when the photographing mode of the FPD 1 is the sleep mode, the scanning line 5, the signal line 6, the radiation detection element 7, and the TFT 8 described above are set at certain time intervals. Is generated in the radiation detection element 7 when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode (refer to the time t = 0 in FIG. 7). It has been found that the charge amount dQ per unit time can be made smaller.

  The reason why such a phenomenon occurs is considered as follows. That is, when the imaging mode of the FPD 1 is the awakening mode, as described above, for example, −5 [V] or the like is supplied to each radiation detection element 7 from the bias power source 14 (see FIG. 2 etc.) via the bias line 9. A reverse bias voltage is applied.

  When the imaging mode of the FPD 1 transitions from the awakening mode to the sleep mode, the application of the reverse bias voltage to each radiation detection element 7 is stopped. However, at that time, as shown in FIG. 18, the voltage Vb applied from the bias power supply 14 to each radiation detection element 7 is actually 0 [V] instantaneously from the reverse bias voltage of the predetermined voltage value Vbias. However, it changes so as to gradually approach 0 [V] in a state having a predetermined time constant. In FIG. 18, Mw represents the period of the awakening mode, and Ms represents the period of the sleep mode.

  While the above phenomenon occurs in the sleep mode, as described above, the panel unit is energized for a predetermined time at certain time intervals, and the reverse bias voltage is applied from the bias power source 14 to each radiation detection element 7. When Vbias is applied, the voltage Vb that gradually increases toward 0 [V] as shown in FIG. 18 decreases to a reverse bias Vbias such as −5 [V].

  When the application of the reverse bias voltage Vbias from the bias power supply 14 to each radiation detection element 7 is stopped after a predetermined time has elapsed, the voltage Vb applied from the bias power supply 14 to each radiation detection element 7 is gradually increased. Change to approach 0 [V]. Therefore, as described above, the voltage Vb applied to each radiation detection element 7 from the bias power supply 14 is returned to 0 [V] by repeatedly energizing the panel unit for a predetermined time at certain time intervals. Instead, the state of taking a negative voltage value between the reverse bias voltage Vbias and a predetermined negative voltage is maintained.

  On the other hand, in a state where the voltage Vb applied to each radiation detection element 7 from the bias power supply 14 of the FPD 1 in the sleep mode is in the above-described state, an operator such as a radiographer takes an image from the console 58 for imaging. Consider a case where the shooting mode of the FPD 1 is changed from the sleep mode to the awake mode by transmitting a wake-up signal to the FPD 1.

  Then, when the operation as described above in the sleep mode is not performed, the voltage Vb applied to each radiation detection element 7 from the bias power supply 14 during the sleep mode returns to 0 [V]. At the time of transition, the voltage Vb applied to each radiation detection element 7 decreases from 0 [V] to a predetermined reverse bias voltage Vbias such as −5 [V]. That is, the change amount of the voltage Vb applied to each radiation detection element 7 in this case is, for example, 5 [V].

  On the other hand, in the sleep mode, when the operation of energizing the panel portion of the FPD 1 for a predetermined time is performed at certain time intervals as described above, each radiation detection is performed from the bias power source 14 during the sleep mode. The voltage Vb applied to the element 7 does not return to 0 [V], and takes a negative voltage value between the reverse bias voltage Vbias and a predetermined negative voltage as described above.

  Therefore, the change amount of the voltage Vb applied to each radiation detection element 7 at the time of transition to the awakening mode is a change amount smaller than the above 5 [V]. The magnitude of the charge amount dQ per unit time generated in the radiation detection element 7 at the time when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode (see the time t = 0 in FIG. 7) is This is determined depending on the amount of change in the voltage Vb applied to each radiation detection element 7 at the time of transition to the awakening mode.

  That is, the magnitude of the charge amount dQ per unit time generated in the radiation detection element 7 at the time when the imaging mode of the FPD 1 is changed from the sleep mode to the awake mode is the detection of each radiation at the transition to the awake mode. If the change amount of the voltage Vb applied to the element 7 is large, the charge amount dQ increases, and if the change amount of the voltage Vb is small, the charge amount dQ also decreases.

  Therefore, as described above, when the shooting mode of the FPD 1 is the sleep mode, the FPD 1 shooting mode is awakened from the sleep mode by energizing the panel unit for a predetermined time at certain time intervals. The amount of charge dQ per unit time generated in the radiation detection element 7 at the time of transition to the mode (refer to the time t = 0 in FIG. 7) can be made smaller.

  Therefore, in the FPD 1, the control means 22 can be configured to energize the panel unit for a predetermined time at predetermined time intervals when the photographing mode of the FPD 1 is in the sleep mode.

  With this configuration, as described above, the amount of charge dQ per unit time generated in the radiation detection element 7 is changed to the time when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode (t in FIG. 7). It is possible to reduce the size at = 0). Then, by reducing the size at the time of transition to the awakening mode, the subsequent charge amount dQ per unit time can be reduced.

  That is, it is possible to further reduce the amount of charge dQ per unit time generated in the radiation detection element 7 at each time t as compared with FIG. 7 or the like when not configured as described above. With this configuration, the charge amount dQ per unit time generated in the radiation detection element 7 can be reduced as a whole.

  Therefore, for example, compared with the case shown in FIG. 13 in which the waiting time WT is set based on the graph of FIG. 7, even if the waiting time WT is made shorter, the offset o due to the dark charge superimposed on the image data D is obtained. And the difference Δ between the offset data O and the offset data O can be sufficiently reduced. Therefore, by configuring as described above and further reducing the charge amount dQ per unit time generated in the radiation detection element 7, the waiting time WT set according to the above-described accumulation time τ is further shortened. It becomes possible.

  Needless to say, the present invention is not limited to the above-described embodiment and the like, and can be appropriately changed without departing from the gist of the present invention.

  For example, in order to save energy (longer life) of the battery 24 (see FIG. 2 etc.) built in the FPD 1, the imaging mode is set to the sleep mode when the patient who is the subject is positioned, and the stage where the positioning is completed (ie, radiation) At the stage when the irradiation of the FPD 1 becomes possible, a method of changing the photographing mode of the FPD 1 from the sleep mode to the awakening mode is effective.

  Therefore, after the positioning of the FPD 1 and the patient H is completed, a wake-up signal is transmitted from the console 58 to the FPD 1 to change the imaging mode of the FPD 1 from the sleep mode to the wake-up mode. Aiming at effect, triggering first button operation of exposure switch 56 as trigger, sending wake-up signal from radiation generator 55 to FPD1 via console 58, wakes up FPD1 shooting mode from sleep mode It may be configured to transition to a mode.

  In the above configuration, since the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode immediately before actual radiation irradiation, the FPD 1 is irradiated with radiation after the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode. Elapsed time t is likely to be shortened. At this time, when the FPD 1 is controlled in an asynchronous manner, the radiation generating device 55 is operated in the same manner as in the synchronous manner when the second stage operation of the exposure switch 56 is performed by an operator such as a radiation technician. Rather than irradiating the radiation for the first time after receiving the interlock release signal from the FPD 1, radiation irradiation can be started immediately when the second stage operation is performed.

  Therefore, the elapsed time t from when the imaging mode of the FPD 1 is changed from the sleep mode to the awakening mode until the radiation is applied to the FPD 1 is likely to be shorter, and the above-described problem of deterioration in the image quality of the medical image p for diagnosis provision Is more likely to occur.

  On the other hand, when the FPD 1 is controlled in a synchronous manner, the waiting time until the interlock release signal is transmitted after the operator performs the second-stage operation on the button of the exposure switch 56 becomes longer. (That is, it becomes longer by the waiting time WT set in accordance with the accumulation time τ), and irradiation of radiation is not started until the interlock release signal is transmitted, so that the imaging mode of the FPD 1 is awakened from the sleep mode. The elapsed time t from when the mode is changed to when the FPD 1 is irradiated with radiation can be made sufficiently long, and there is no problem of deterioration of the image quality of the medical image p for diagnosis provision.

  Therefore, when the asynchronous FPD 1 is used, in order to prevent an operator such as a radiologist from performing the second button operation immediately after the first button operation, in other words, the operator waits. In order to perform the button operation of the second stage after the time WT has elapsed, as described in the above embodiment, the notification device is configured to accurately notify an operator such as a radiologist. It is preferable to do.

  At this time, an operator such as a radiologist is present in the vicinity of the exposure switch 56, and it is assumed that the screen displayed on the display unit 58a of the console 58 cannot be visually recognized. The display unit 58a displays that it is possible to shoot and informs that it is possible to shoot with sound such as a beep sound (that is, the second-stage button operation on the exposure switch 56 is possible). It is preferable to configure.

1 FPD (radiological imaging equipment)
5 Scanning line 6 Signal line 7 Radiation detection element 8 TFT (switch element)
14 Bias power supply 15 Scan driving means 17 Reading circuit 22 Control means 50 Medical image system 55 for providing diagnosis Radiation generator 58 Console (console, notification device)
D Image data H Subject T Time WT Wait time Vbias Reverse bias voltage δT Predetermined shooting interval τ Accumulation time

Claims (2)

A plurality of scanning lines and a plurality of signal lines;
A plurality of radiation detection elements arranged two-dimensionally;
A switch element connected to each of the scanning lines, and discharging a charge accumulated in the radiation detection element to the signal line when an on-voltage is applied;
A bias power source for applying a reverse bias voltage to each of the radiation detection elements;
A panel portion having
Scanning drive means for switching a voltage applied to each scanning line between an on-voltage and an off-voltage,
A readout circuit for reading out the electric charge emitted to the signal line as image data;
Control means for controlling at least the scanning drive means and the readout circuit to perform the readout processing of the image data;
A radiographic imaging device comprising:
A radiation generator for irradiating the radiation imaging apparatus with radiation through a subject; and
A notification device;
With
The radiographic image capturing apparatus supplies an imaging mode, an awakening mode capable of performing imaging by supplying power to each functional unit including at least the control unit, and supplying power only to necessary functional units to perform imaging. Is configured to be able to transition between sleep modes that cannot be performed,
The control means of the radiographic imaging apparatus applies reset voltage to the scanning lines from the scanning driving means after performing reset processing of the radiation detecting elements during imaging. The charge accumulation state in which charges generated in each radiation detection element due to radiation irradiation in the off state are accumulated in each radiation detection element is continued for a set accumulation time, and then at least the scanning drive Controlling the means and the readout circuit to perform the readout processing of the image data,
The control unit of the notification device or the radiographic imaging device counts the time since the previous imaging was completed in the radiographic imaging device, and when the time has passed a predetermined imaging interval, The notification device is configured to notify that it is possible to perform imaging by irradiating radiation from the radiation generation device,
The predetermined imaging interval ranges from a waiting time set according to the accumulation time at the time of subsequent imaging in the radiographic imaging device to a waiting time set according to the accumulation time at the previous imaging and once A medical image system for providing diagnosis, which is set based on a time interval obtained by subtracting the time required for imaging.   The control unit of the radiographic image capturing apparatus energizes the panel unit for a predetermined time at predetermined time intervals when the imaging mode is the sleep mode. The medical image system for providing diagnosis as described.

Images