WO2013047193A1

WO2013047193A1 - Radiography system

Info

Publication number: WO2013047193A1
Application number: PCT/JP2012/073256
Authority: WO
Inventors: 西納直行; 大田恭義; 岩切直人; 中津川晴康
Original assignee: 富士フイルム株式会社
Priority date: 2011-09-28
Filing date: 2012-09-12
Publication date: 2013-04-04

Abstract

This radiography system has: a radiography device having a radiation radiating system, which has a radiation source, and a radiograph outputting system, which converts the radiation from the radiation source having passed through a subject to a radiograph, and outputs the result; and a system control unit that controls the radiography device in a manner so as to execute radiography at a set imaging timing. The radiograph outputting system has a first imaging unit and a second imaging unit that each have different sensitivity characteristics, and that convert radiation into radiographs. The system control unit has a synchronization unit that synchronizes the imaging timing over a plurality of successive instances by the first imaging unit and the second imaging unit.

Description

Radiation imaging system

The present invention relates to a radiographic imaging system capable of obtaining a moving image and a still image of a radiographic image by executing radiography at a set frame rate using a radiographic imaging device.

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

On the other hand, at the time of surgery, contrast imaging, or treatment of fractures, etc., radiation image information can be read and displayed immediately from the radiation detector after imaging in order to quickly and accurately treat the patient. is necessary. As a radiation detector capable of meeting such demands, a solid-state detection element (referred to as a pixel) that converts radiation directly into an electrical signal, or converts radiation into visible light with a scintillator and then converts it into an electrical signal for reading. A radiation detector referred to as a flat panel detector (FPD) using the above has been developed.

In particular, by performing radiography at a set frame rate, a moving image based on a radiographic image is displayed on a monitor, so that, for example, the state of catheter entry with respect to a subject can be grasped in real time. An X-ray diagnostic imaging apparatus has also been proposed (see Japanese Patent Application Laid-Open Nos. 2011-004966 and 2002-102213).

Conventionally, in radiographic imaging, the same part of the subject is imaged with different tube voltages, and image processing (hereinafter referred to as “difference”) is performed by weighting the radiographic images obtained by imaging with each tube voltage. By performing "subtraction image processing"), a radiographic image in which one of an image portion corresponding to a hard tissue such as a bone portion and an image portion corresponding to a soft tissue in the image is emphasized and the other is removed ( Hereinafter, a technique for obtaining an “energy subtraction image”) is known. For example, when an energy subtraction image corresponding to the soft tissue of the chest is used, it is possible to see a lesion hidden by the ribs, and the diagnostic performance can be improved.

When photographing with changing the tube voltage, since it is continuously exposed twice, there is a high possibility that an image with good diagnostic performance cannot be obtained when there is a body movement of a patient or the like. Therefore, subtraction image processing has been proposed with one exposure (see Japanese Patent Application Laid-Open No. 2010-056396).

However, in the past, it was possible to perform energy-sub shooting by stacking two panels with different characteristics, but for still image use, energy subtraction shooting for moving images (hereinafter referred to as energy-sub moving image shooting) I could not respond. This is because the required specifications differ between still images and moving images, and it is impossible to realize a highly versatile device that satisfies both. Of course, since there is a problem of body movement during moving image shooting, it is desirable to be able to perform subtraction image processing with a single exposure.

In addition, since the radiation imaging apparatus is expensive, it is desired that a large number of procedures can be taken with a more versatile device than introducing a plurality of dedicated machines. This is because the places where radiography can be performed are limited, and there is a problem of restriction of the installation location.

The present invention has been made in consideration of such problems, and can perform still image shooting, moving image shooting, and energy-sub moving image shooting with one system. An object of the present invention is to provide a radiographic imaging system that can perform subtraction image processing and has high versatility.

[1] A radiographic imaging system according to the present invention includes a radiation irradiation system having a radiation source, and a radiation image output system that converts the radiation from the radiation source that has passed through the subject into a radiation image and outputs the radiation image. An image capturing apparatus; and a system control unit that executes and controls radiation imaging at a set imaging timing. The radiation image output systems have different characteristics, and the radiation is converted into a radiation image. The system control unit includes a synchronization unit that synchronizes a plurality of successive imaging timings of the first imaging unit and the second imaging unit. To do.

Here, “characteristics are different” means that at least one or more of the sensitivity, resolution, imaging area size, driving speed, etc. of the first imaging unit and the second imaging unit is different. The driving speed varies depending on the resolution, the imaging region size, and the like, but also varies depending on the structure of the element that transfers the accumulated charge to the output side. Examples of the structure of this element include a thin film transistor made of amorphous silicon, a thin film transistor made of an organic material, a thin film transistor made of an oxide semiconductor (for example, InGaZnOx: IGZO), a CMOS transistor, and the like.

[2] In the present invention, the system control unit may execute and control radiation imaging by switching between still image imaging and moving image imaging as required.

[3] In the present invention, the system control unit performs subtraction based on a plurality of radiographic images obtained by the first imaging unit and the second imaging unit at a plurality of consecutive imaging timings by the synchronization unit. You may have an energy subtraction animation creation part which performs image processing and produces the energy subtraction image of a animation.

[4] In the present invention, the synchronization unit may synchronize the imaging timing so that the charge accumulation period in the first imaging unit and the charge accumulation period in the second imaging unit overlap at least partially. Good.

[5] In the present invention, the synchronization unit synchronizes the imaging timing to synchronize the start of the charge accumulation period in the first imaging unit and the start of the charge accumulation period in the second imaging unit. Also good.

[6] In the present invention, the synchronization unit synchronizes the imaging timing to synchronize the end of the charge accumulation period in the first imaging unit and the end of the charge accumulation period in the second imaging unit. Also good.

[7] In the present invention, the synchronization unit synchronizes the imaging timing to synchronize the start of the charge accumulation period in the first imaging unit and the start of the charge accumulation period in the second imaging unit, In addition, the end of the charge accumulation period in the first imaging unit and the end of the charge accumulation period in the second imaging unit may be synchronized.

[8] In the present invention, the first imaging unit is sensitive to at least a low energy component of the radiation, and the second imaging unit is sensitive to at least a high energy component of the radiation. May be.

[9] In the present invention, a maximum frame rate of the imaging timing corresponding to the first imaging unit may be larger than a frame rate of the imaging timing corresponding to the second imaging unit.

[10] In the present invention, the spatial resolution of the second imaging unit may be higher than that of the first imaging unit.

[11] In the present invention, the number of pixels of the first image pickup unit is n, the number of pixels the second imaging unit may be an n ^2.

[12] In the present invention, the area of the sensitive part of the second imaging unit may be larger than the area of the sensitive part of the first imaging unit.

[13] In the present invention, at least the second imaging unit may perform conversion into a radiation image by thinning or binning according to the setting of the system control unit.

[14] In the present invention, the system control unit may set at least thinning out or binning of the second imaging unit in accordance with the imaging timing synchronized by the synchronization unit.

[15] In the present invention, a light shielding layer may be provided between the first imaging unit and the second imaging unit.

[16] In the present invention, a filter having a characteristic of absorbing a specific wavelength may be provided between the first imaging unit and the second imaging unit.

[17] In the present invention, the first imaging unit may be installed on the radiation incident side.

[18] In the present invention, the second imaging unit may be installed on the radiation incident side.

According to the radiographic image capturing system of the present invention, it is possible to perform still image capturing, moving image capturing, and energy subtraction image capturing with a single system, and subtraction with a single exposure. Image processing can be performed, and a highly versatile radiographic imaging system can be obtained.

It is a block diagram which shows the radiographic imaging system which concerns on this Embodiment. It is a block diagram which mainly shows the structure of the radiation irradiation system of a radiographic imaging system, and a radiation detection apparatus. It is a perspective view which shows the structure of a radiation detection apparatus partially fractured | ruptured. It is a perspective view which shows schematic structure of a radiation detector. 5A to 5C are cross-sectional views showing first to third modes of the radiation detector. 6A and 6B are sectional views showing fourth and fifth modes of the radiation detector. 7A to 7C are cross-sectional views showing sixth to eighth embodiments of the radiation detector. 8A to 8C are sectional views showing ninth to eleventh aspects of the radiation detector. 9A and 9B are sectional views showing twelfth and thirteenth aspects of the radiation detector. 10A to 10C are sectional views showing fourteenth to sixteenth aspects of the radiation detector. 11A and 11B are sectional views showing the seventeenth and eighteenth aspects of the radiation detector. It is a circuit diagram which shows the structure of a radiation detection apparatus, and shows the structure of a radiation detector especially. It is a block diagram which mainly shows the structure of the system control part of a radiographic imaging system. It is a flowchart which shows the processing operation (still image imaging process) of a radiographic imaging system. It is a time chart which shows the processing operation (still image photography processing) of a radiographic imaging system. It is a flowchart which shows the processing operation (moving image imaging process) of a radiographic imaging system. It is a time chart which shows the processing operation (moving image imaging process) of a radiographic image imaging system. It is a flowchart which shows the processing operation (energy sub imaging process) of a radiographic imaging system. It is a time chart which shows the processing operation (energy sub imaging process) of a radiographic imaging system. 20A to 20C are time charts showing examples (first to third cases) in which the charge accumulation period in the first imaging unit and the charge accumulation period in the second imaging unit overlap. 21A and 21B are time charts showing an example (fourth and fifth cases) in which the charge accumulation period in the first imaging unit and the charge accumulation period in the second imaging unit overlap. 22A to 22C are explanatory views showing a radiation irradiation system having a plurality of radiation sources.

Hereinafter, embodiments of the radiation image capturing system according to the present invention will be described with reference to FIGS. 1 to 22C.

First, as shown in FIG. 1, the radiographic imaging system 10 according to the present exemplary embodiment performs system control for performing radiographic imaging on the radiographic imaging apparatus 12 and the radiographic imaging apparatus 12 at a set imaging timing. Part 14. A console 16 is connected to the system control unit 14 so that data communication with the console 16 is possible. Connected to the console 16 are a monitor 18 for image observation and diagnostic imaging, and an input device 20 (keyboard, mouse, etc.) for operation input. Operators (physicians and radiographers) are required to provide radiation irradiation energy (tube voltage, Tube current, irradiation time, etc.) and the frame rate of radiography are set using the input device 20. Data input using the input device 20 and data created and edited by the console 16 are input to the system control unit 14. Furthermore, for example, the display of a moving image energy subtraction image (energy sub moving image) can be instructed via the input device 20. The radiation image from the system control unit 14 is supplied to the console 16 and displayed on the monitor 18.

The radiographic image capturing apparatus 12 converts a radiation irradiation system 28 that irradiates a radiation 26 toward the subject 24 on the photographing table 22 with the set irradiation energy, and converts the radiation 26 that has passed through the subject 24 into a radiation image to perform system control. A radiation image output system 29 for outputting to the unit 14. The radiation image output system 29 transmits and receives data such as a radiation image between the radiation detection device 30 that converts the radiation 26 that has passed through the subject 24 into a radiation image with a set gain and the radiation detection device 30 and the system control unit 14. And a detection device control unit 32 that controls (including movement drive) the radiation detection device 30 based on an instruction from the system control unit 14.

The movement detection of the radiation detection apparatus 30 is performed when a relatively wide range is imaged, for example, a moving image of the spine or a moving image of the catheter entry position. That is, in such imaging, a movement control signal based on an operation input from an operator (doctor or radiographer) is output from the system control unit 14 and input to the detection device control unit 32. Based on the movement control signal from the system control unit 14, the detection device control unit 32 controls the movement drive mechanism (not shown) to move the radiation detection device 30.

As shown in FIG. 2, the radiation irradiation system 28 is based on a radiation source 34, a radiation source controller 36 that controls the radiation source 34 based on an instruction from the system controller 14, and an instruction from the system controller 14. And an automatic collimator unit 38 that widens or narrows the irradiation area of the radiation 26.

As shown in FIG. 3, the radiation detection device 30 includes a housing 40 made of a material that transmits the radiation 26. Inside the housing 40, the radiation detector 42 is disposed opposite to one surface of the radiation detector 42 (a surface near the irradiation surface 40 a of the housing 40), and the radiation 26 scattered by the subject 24 is scattered. It has a grid 44 to be removed, and a lead plate 46 that is disposed opposite to the other surface of the radiation detector 42 and absorbs back scattered radiation of the radiation 26. Note that the irradiation surface 40 a of the housing 40 may be configured as a grid 44.

Further, the radiation detection apparatus 30 further transmits / receives a signal including a radiation image from the radiation detector 42 to / from the battery 48 as a power source, a cassette control unit 50 that drives and controls the radiation detector 42. A transceiver 52 is accommodated. The radiation image output from the transceiver 52 is input to the system control unit 14 and the console 16 via the detection device control unit 32 and is displayed on the monitor 18. That is, when still image shooting is performed, one radiographic image is input to the system control unit 14, and thus the radiographic image is displayed on the monitor 18 as a still image. When shooting for moving images is performed, radiographic images based on the radiographic imaging at the set frame rate are sequentially input to the system control unit 14, so that moving images of the radiographic images are displayed on the monitor 18 in real time. It will be. A moving image is a moving image or CT (computer tomography image) for positioning the imaging region of at least the subject 24, the operation timing of a medical instrument (such as a catheter) on the subject 24, and the like. It includes not only a single shot image but also a plurality of shot images obtained by continuous shooting (continuous shooting).

The cassette control unit 50 and the transceiver 52 are provided with lead plates or the like on the irradiation surface side of the cassette control unit 50 and the transceiver 52 in order to avoid damage due to radiation 26 irradiation. Is preferred.

Here, the structure of the radiation detector 42 will be described with reference to FIGS. 4 to 11B.

As shown in FIG. 4, the radiation detector 42 includes two imaging units (a first imaging unit 54A and a second imaging unit 54B) having different characteristics. Here, “characteristics are different” means that at least one or more of the sensitivity, resolution, imaging area size, driving speed, and the like of the first imaging unit 54A and the second imaging unit 654B are different. The driving speed varies depending on the resolution, the imaging region size, and the like, but also varies depending on the structure of the element that transfers the accumulated charge to the output side. Examples of the structure of this element include a thin film transistor made of amorphous silicon, a thin film transistor made of an organic material, a thin film transistor made of an oxide semiconductor (for example, InGaZnOx: IGZO), a CMOS transistor, and the like.

The first imaging unit 54A is sensitive to at least the low energy component of the radiation 26, and the second imaging unit 54B is sensitive to at least the high energy component of the radiation. Further, the first imaging unit 54A and the second imaging unit 54B are stacked. Thereby, energy subtraction imaging can also be performed by one exposure. The order of lamination is arbitrary, and a specific aspect thereof will be described later.

The first imaging unit 54A is an imaging unit for moving images, and the second imaging unit 54B is an imaging unit for still images. The spatial resolution of the second imaging unit 54B is set higher than that of the first imaging unit 54A. Thereby, a high-definition still image can be obtained.

Specifically, the first imaging unit 54A has a limited number of pixels so that it can capture a moving image at a set frame rate (for example, 15 frames / second to 60 frames / second). The second imaging unit 54B has a larger number of pixels than the first imaging unit 54A so that a high-definition still image can be obtained. In addition, the first imaging unit 54A is set such that the area seen from above (the area of the sensitive portion where the pixels are arranged) is set smaller than that of the second imaging unit 54B, and a relatively small range of moving images at a high frame rate. An image can be taken. Of course, the area of the first imaging unit 54A viewed from the top surface and the area of the second imaging unit 54B viewed from the top surface may be substantially the same.

For example, the number of pixels per unit length in the vertical direction (vertical direction) of the first imaging unit 54A is G1v, the number of pixels in the horizontal direction (horizontal direction) per unit length of the first imaging unit 54A is G1h, 2 When the number of pixels in the vertical direction (vertical direction) per unit length of the imaging unit 54B is G2v, and the number of pixels per unit length in the horizontal direction (horizontal direction) of the second imaging unit 54B is G2h,
G2v = kv × G1v
G2h = kh × G1h
It has the relationship shown in Here, kv and kh are proportional coefficients (integer) of 2 or more.

In particular, in this embodiment, when the number of pixels per unit area of the first image pickup unit 54A is n, as the number of pixels per unit area in the second imaging unit 54B is n ^2, the coefficient kv and kh Is set. As a result, the first image capturing unit 54A can perform moving image shooting at a high frame rate of 30 frames / second or more, and the second image capturing unit 54B can obtain a high-definition still image. . In this case, for example, assuming that the drive clock cycles of the first imaging unit 54A and the second imaging unit 54B are the same and signal charges are read from all pixels per unit area, the first imaging unit 54A and the second imaging unit 54A The time from the reading start time of the second imaging unit 54B to the reading end time is kv × kh (= n) times that of the first imaging unit 54A in the second imaging unit 54B. That is, when considering the case where the second imaging unit 54B also performs moving image shooting, the maximum frame rate of the first imaging unit 54A is larger than the frame rate of the second imaging unit 54B. It becomes more remarkable when the entire area of the second imaging unit 54B is larger than the entire area of the first imaging unit 54A. In the above description, the comparison is made with the drive clock cycle being the same, but in actuality, the drive clock cycle may be different between the first imaging unit 54A and the second imaging unit 54B depending on the specification.

Next, specific examples of the first imaging unit 54A and the second imaging unit 54B will be described with reference to FIGS. 5A to 11B. As specific examples of the first imaging unit 54A and the second imaging unit 54B, for example, there are 18 modes.

As shown in FIG. 5A, the first mode is the sensor substrate 56, the first scintillator 58A installed on one surface of the sensor substrate 56 (the surface on the incident side of the radiation 26), and the other of the sensor substrate 56. And a second scintillator 58B installed on the surface.

The sensor substrate 56 is formed on, for example, the glass substrate 60, the first photodiode portion 62 A formed on one surface of the glass substrate 60 (the surface on the incident side of the radiation 26), and the other surface of the glass substrate 60. And a second photodiode portion 62B. The first photodiode portion 62A and the second photodiode portion 62B can employ a configuration in which a large number of photodiodes each made of amorphous silicon (a-Si) are arranged in accordance with the pixels. In this case, the first imaging unit 54A is configured by the first scintillator 58A and the first photodiode unit 62A, and the second imaging unit 54B is configured by the second scintillator 58B and the second photodiode unit 62B.

In addition, on one surface of the glass substrate 60, a plurality of gate lines and a plurality of signal lines for reading out the charges photoelectrically converted by the first photodiode portion 62A and TFTs (thin film transistors) corresponding to the pixels are formed. Similarly, on the other surface of the glass substrate 60, a plurality of gate lines, a plurality of signal lines, and TFTs (thin film transistors) corresponding to the pixels for reading out the charges photoelectrically converted by the second photodiode portion 62B are formed. Has been.

Instead of the glass substrate 60, a crystalline silicon substrate or a SiC substrate (silicon carbide substrate) may be used. In this case, a CMOS circuit including a TFT may be formed.

As the first scintillator 58A, for example, a BaFBr phosphor (blue emission) having sensitivity to a low energy component is used, and for example, a CaWO ₄ phosphor (blue emission) having sensitivity to a high energy component is used as the second scintillator 58B. be able to. Thereby, of the radiation 26 incident on the radiation detector 42, the low energy component is converted into visible light by the first scintillator 58A and is incident on the first photodiode 62A, and the high energy component is incident on the second scintillator 58B. Then, the light is converted into visible light and is incident on the second photodiode portion 62B. In this case, even if a filter that absorbs a specific wavelength (for example, a filter that absorbs a blue light-emitting component) or a light shielding layer 64 is installed between the glass substrate 60 and the first photodiode portion 62A, crosstalk can be prevented. Good. In addition, a light reflecting layer is installed at each end of the first scintillator 58A and the second scintillator 58B (the end where the first photodiode unit 62A and the second photodiode unit 62B are not installed), and the first photo The light receiving efficiency in the diode part 62A and the second photodiode part 62B may be improved.

As the first scintillator 58A, a columnar crystal CsI: Na phosphor (blue light emission) or CsI: Tl phosphor (green light emission) may be used. A radiographic image (first radiographic image D1) using a low energy component is required to have high image quality because an image of a complex tissue such as a soft tissue is extracted. Since the columnar crystals can suppress the divergence of light emission, the first radiation image D1 can be improved in image quality, and the above-described requirements can be met.

As shown in FIG. 5B, the second mode has substantially the same configuration as the first mode described above, but differs in that an organic photoconductor (OPC) is used instead of the photodiode. . A first organic photoconductor 66A is installed between the sensor substrate 56 and the first scintillator 58A, and a second organic photoconductor 66B is installed between the sensor substrate 56 and the second scintillator 58B. In this case, the first imaging unit 54A is configured by the first scintillator 58A and the first organic photoconductor 66A, and the second imaging unit 54B is configured by the second scintillator 58B and the second organic photoconductor 66B.

The sensor substrate 56 corresponds to, for example, a resin substrate 68, and a plurality of gate lines, a plurality of signal lines, and pixels for reading out charges photoelectrically converted by the first organic photoconductor 66A on one surface of the resin substrate 68. A TFT made of an organic TFT (thin film transistor made of an organic material) or an oxide semiconductor (for example, InGaZnOx: IGZO) is formed, and similarly, the other surface of the resin substrate 68 is photoelectrically converted by the second organic photoconductor 66B. A plurality of gate lines and a plurality of signal lines for reading out electric charges and organic TFTs or oxide semiconductor TFTs corresponding to the pixels are formed.

Instead of the resin substrate 68, a crystalline silicon substrate or a SiC substrate (silicon carbide substrate) may be used. In this case, a CMOS circuit including a TFT may be formed.

For the first organic photoconductor 66A, if the first scintillator 58A is, for example, BaFBr or CsI: Na (columnar crystal) that emits blue light, an organic photoconductor that absorbs blue light is used, and the first scintillator 58A is used. If CsI: Tl (columnar crystal) emits green light, an organic photoconductor that absorbs green light is used.

On the other hand, the second organic photoconductor 66B is an organic photoconductor that absorbs blue light if the second scintillator 58B emits blue light, for example, CaWO ₄ , and the second scintillator 58B is green light, for example, GOS. If present, an organic photoconductor that absorbs green light is used.

3rd aspect has the structure which combined the 1st aspect and 2nd aspect which were mentioned above, as shown to FIG. 5C. That is, the sensor substrate 56 having the first photodiode portion 62A, the first scintillator 58A installed on one surface of the sensor substrate 56, and the second organic installed between the sensor substrate 56 and the second scintillator 58B. A photoconductor 66B. The second photodiode portion 62B is not installed on the sensor substrate 56. In this case, the first imaging unit 54A is configured by the first scintillator 58A and the first photodiode unit 62A, and the second imaging unit 54B is configured by the second scintillator 58B and the second organic photoconductor 66B.

For example, BaFBr is used as the first scintillator 58A, GOS is used as the second scintillator 58B, and an organic photoconductor that absorbs green light, for example, is used as the second organic photoconductor 66B. Since GOS emits blue light slightly, it is preferable to interpose a filter 70 that absorbs blue light on the sensor substrate 56 in order to prevent crosstalk.

As shown in FIG. 6A, the fourth aspect is different from the second aspect in that BaFBr / GOS obtained by blending BaFBr and GOS is used as the first scintillator 58A and the second scintillator 58B.

As shown in FIG. 6B, the fifth aspect is different from the third aspect in that BaFBr / GOS obtained by blending BaFBr and GOS is used as the first scintillator 58A and the second scintillator 58B.

In these fourth and fifth aspects, the first scintillator 58A and the second scintillator 58B emit blue light in response to the low energy component of the radiation 26, and green light in response to the high energy component of the radiation 26. Exit. Therefore, in the first organic photoconductor 66A and the first photodiode portion 62A, blue light from the first scintillator 58A is mainly incident and absorbed, but leakage light (blue light) from the second scintillator 58B is also incident. Is absorbed. On the other hand, in the second organic photoconductor 66B, green light from the second scintillator 58B is mainly incident and absorbed, but leakage light (green light) from the first scintillator 58A is also incident and absorbed. Thereby, since the first scintillator 58A and the second scintillator 58B can be effectively used in the first organic photoconductor 66A and the second organic photoconductor 66B, the thicknesses of the first scintillator 58A and the second scintillator 58B are reduced. The thickness can be reduced, which is advantageous for reducing the height of the radiation detector 42. It is not necessary to install the filter 70 that absorbs blue light on the sensor substrate 56.

As shown in FIG. 7A, the sixth mode includes a first sensor substrate 56A installed on the incident side of the radiation 26, a second sensor substrate 56B installed facing the first sensor substrate 56A, and a first sensor board 56A. A light reflecting layer 72 disposed between the sensor substrate 56A and the second sensor substrate 56B, a first scintillator 58A disposed between the first sensor substrate 56A and the light reflecting layer 72, and a second sensor substrate 56B. And a second scintillator 58 B installed between the light reflection layer 72.

A first photodiode portion 62A is installed in a portion of the first sensor substrate 56A that faces the first scintillator 58A, and a second photodiode portion 62B is placed in a portion of the second sensor substrate 56B that faces the second scintillator 58B. Is installed.

As the first scintillator 58A, for example, a BaFBr phosphor (blue light emission) having sensitivity to a low energy component is used, and for example, a CaWO ₄ phosphor (blue light emission) having sensitivity to a high energy component is used as the second scintillator 58B. be able to. Thereby, of the radiation 26 incident on the radiation detector 42, the low energy component is converted into visible light by the first scintillator 58A and is incident on the first photodiode 62A, and the high energy component is incident on the second scintillator 58B. Then, the light is converted into visible light and is incident on the second photodiode portion 62B. In this case, since the light reflecting layer 72 is provided between the first scintillator 58A and the second scintillator 58B, crosstalk can be effectively prevented, and the first photodiode portion 62A and the second photo diode are separated. The light receiving efficiency in the diode part 62B is improved.

As the first scintillator 58A, a columnar crystal CsI: Na phosphor (blue light emission) or CsI: Tl phosphor (green light emission) may be used.

As shown in FIG. 7B, the seventh aspect has substantially the same configuration as the sixth aspect described above, but the first sensor board 56A (the first photodiode portion 62A is not installed) and the first scintillator. 58A, the first organic photoconductor 66A is installed, and the second organic photoconductor 66B is provided between the second sensor substrate 56B (the second photodiode portion 62B is not installed) and the second scintillator 58B. It is different in that is installed.

As shown in FIG. 7C, the eighth aspect has substantially the same configuration as the sixth aspect described above, but the second sensor substrate 56B (the second photodiode portion 62B is not installed) and the second scintillator. 58B is different in that a second organic photoconductor 66B is installed. If the second scintillator 58B is, for example, GOS that emits green light, an organic photoconductor that absorbs green light is used as the second organic photoconductor 66B.

As shown in FIG. 8A, in the ninth mode, a scintillator 58 in which two kinds of phosphors are blended is installed between the first sensor substrate 56A and the second sensor substrate 56B, and among the first sensor substrates 56A, The first photodiode portion 62A is installed at a portion facing the scintillator 58, and the second photodiode portion 62B is installed at a portion facing the scintillator 58 in the second sensor substrate 56B.

In this case, since the so-called surface reading method (ISS (Irradiation Side Sampling) method) can be adopted for the low energy component, it is possible to suppress the diffusion and attenuation of light, and to increase the resolution of the first radiation image D1. Can do.

As the scintillator, BaFBr / CaWO ₄ in which BaFBr and CaWO ₄ are blended, BaFBr / GOS in which BaFBr and GOS are blended, or the like can be used. In this case, it is preferable to distribute the blend of the two types of phosphors. The ratio of BaFBr may be increased toward one surface of the scintillator so that the incident side of the radiation 26 is sensitive to low energy components.

As shown in FIG. 8B, the tenth aspect has substantially the same configuration as the ninth aspect, but between the first sensor board 56A (the first photodiode portion 62A is not installed) and the scintillator 58. The first organic photoconductor 66A is installed, and the second organic photoconductor 66B is installed between the second sensor substrate 56B (the second photodiode portion 62B is not installed) and the scintillator 58. It is different. In this case, the first organic photoconductor 66A is an organic photoconductor that absorbs blue light. The second organic photoconductor 66B uses an organic photoconductor that absorbs blue light if the scintillator 58 is, for example, BaFBr / CaWO ₄ , and absorbs green light if the scintillator 58 is, for example, BaFBr / GOS. An organic photoconductor is used.

As shown in FIG. 8C, the eleventh aspect has substantially the same configuration as the ninth aspect, but between the second sensor substrate 56B (the second photodiode portion 62B is not installed) and the scintillator 58. Is different in that the second organic photoconductor 66B is installed. For the second organic photoconductor 66B, if the scintillator 58 is, for example, BaFBr / GOS, an organic photoconductor that absorbs green light is used. In this case, by increasing the ratio of BaFBr toward one surface of the scintillator 58 so that the incident side of the radiation 26 is sensitive to low energy components, crosstalk due to slight blue light emission from the GOS is suppressed. Can do.

In the twelfth aspect, as shown in FIG. 9A, the first organic photoconductor 66A and the second organic photoconductor 66B are arranged alternately on one surface of the sensor substrate 56, for example. The first scintillator 58A is installed on one surface side of the body 66A and the second organic photoconductor 66B, and the second scintillator 58B is installed on the other surface of the sensor substrate 56.

In this case, the first scintillator 58A uses, for example, a BaFBr phosphor (blue light emission) having sensitivity to a low energy component, and the second scintillator 58B uses, for example, a GOS phosphor (green light emission) having sensitivity to a high energy component. be able to. Alternatively, BaFBr / GOS obtained by blending BaFBr and GOS can be used as the first scintillator 58A and the second scintillator 58B.

The thirteenth aspect has substantially the same configuration as the twelfth aspect as shown in FIG. 9B, but differs in that the first scintillator 58A is not installed. In this case, BaFBr / GOS obtained by blending BaFBr and GOS can be used as the second scintillator 58B.

As shown in FIG. 10A, the fourteenth aspect has substantially the same configuration as the first aspect described above, but instead of the first scintillator 58A and the first photodiode portion 62A, the radiation 26 is directly converted into an electrical signal. The difference is that the solid detection element 74 is made of a substance such as amorphous selenium (a-Se) to be converted. As the second scintillator 58B, for example, a CaWO ₄ phosphor (blue light emission) or a GOS phosphor (green light emission) having sensitivity to high energy components can be used. A bias voltage Vb is applied to the solid state detection element 74.

Since the a-Se solid-state detection element 74 is sensitive to blue light, when the CaWO ₄ phosphor (blue light emission) is used as the second scintillator 58B, blue light is emitted between the sensor substrate 56 and the solid-state detection element 74. In order to prevent crosstalk, it is preferable to interpose a filter that absorbs.

As shown in FIG. 10B, the fifteenth aspect has substantially the same configuration as the sixth aspect described above, but instead of the first scintillator 58A and the first photodiode portion 62A, the radiation 26 is directly converted into an electrical signal. The difference is that the solid detection element 74 is made of a substance such as amorphous selenium (a-Se) to be converted. As the second scintillator 58B, for example, a CaWO ₄ phosphor (blue light emission) or a GOS phosphor (green light emission) having sensitivity to high energy components can be used.

In this case, since the so-called surface reading method (ISS method) can be adopted for the low energy component, the image quality of the first radiation image D1 by the low energy component can be improved.

Since the a-Se solid-state detection element 74 has sensitivity to blue light, when the GOS that emits green light is used as the second scintillator 58B, the light reflection layer 72 is not necessarily installed, but the second scintillator 58B In order to receive the light emitted by the second photodiode portion 62B as much as possible, the light reflecting layer 72 is preferably provided.

The sixteenth aspect has a configuration opposite to the fifteenth aspect described above, as shown in FIG. 10C. That is, the second sensor substrate 56B having the second photodiode portion 62B and the second scintillator 58B are installed on the incident side of the radiation 26, and the first sensor substrate 56A and the a− are opposite to the incident side of the radiation 26. A Se solid detection element 74 is installed.

Normally, the a-Se solid state detection element 74 deteriorates (crystallizes) by repeated irradiation of the radiation 26. In this embodiment, the a-Se solid state detection element 74 is moved away from the incident side of the radiation 26. Therefore, deterioration can be suppressed. Further, the a-Se solid state detection element 74 is crystallized at a high temperature and its function is deteriorated. However, since the cooling plate 76 can be installed on the solid state detection element 74 side, the crystallization is further suppressed. Can do.

As shown in FIG. 11A, the seventeenth aspect has substantially the same configuration as the first aspect described above, but differs in that the first scintillator 58A is used as the second scintillator 58B. That is, the first scintillator 58A is installed on the incident side of the radiation 26 and on the opposite side. In this case, it is preferable to install a light reflection layer 72 on the sensor substrate 56 in order to suppress crosstalk.

As shown in FIG. 11B, the eighteenth aspect has substantially the same configuration as the sixth aspect described above, but differs in that the first scintillator 58A is installed on the radiation 26 incident side and the opposite side, respectively. . Also in this case, in order to suppress crosstalk, it is preferable to install the light reflecting layer 72 between the first scintillators 58A.

In the seventeenth and eighteenth aspects, BaFBr (blue light emission), CsI: Tl phosphor (green light emission), or the like can be used as the first scintillator 58A.

In the seventeenth and eighteenth aspects, the lower energy component is absorbed more on the incident side of the radiation 26, and the absorption ratio of the remaining high energy component is increased on the opposite side of the incident side of the radiation 26. The first radiation image D1 with a low energy component is taken out through the first photodiode portion 62A on the incident side of the light, and the radiation image with the high energy component (second radiation image) through the second photodiode portion 62B on the opposite side. D2) will be taken out.

Usually, as the columnar crystal such as CsI: Tl phosphor becomes thicker, fusion between the columnar shapes is more likely to occur, so it is necessary to lower the filling rate in the initial stage of vapor deposition. In this case, the light emission amount is reduced. However, since the seventeenth and eighteenth aspects are divided and configured, it is not necessary to lower the filling rate in advance. Accordingly, it is possible to avoid a decrease in the light emission amount.

Next, as an example, FIG. 12 relates to the circuit configuration of the radiation detection apparatus 30 when the indirect conversion type radiation detector 42 is employed, for example, the configuration of the readout circuit (first readout circuit 78A) of the first imaging unit 54A. Details will be described with reference to FIG.

The first imaging unit 54A includes, for example, an array of thin film transistors (hereinafter referred to as TFTs 84) in a matrix form, in which the photoelectric conversion layer 82 in which each pixel 80 made of a material such as a-Si that converts visible light into an electrical signal is formed. It has a structure arranged on the top. In this case, since charges generated by converting visible light into electrical signals (analog signals) are accumulated in each pixel 80, for example, by sequentially turning on the TFT 84 for each row, the charges are used as image signals. Can be read.

The first readout circuit includes a TFT 84 connected to each pixel 80, a gate line 86 connected to the TFT 84 and extending parallel to the row direction, and a signal line 88 connected to the TFT 84 and extending parallel to the column direction. Each gate line 86 is connected to a line scan driver 90, and each signal line 88 is connected to a multiplexer 92. Control signals Von and Voff for controlling on / off of the TFTs 84 arranged in the row direction are supplied from the line scanning drive unit 90 to the gate line 86. In this case, the line scan driving unit 90 includes a plurality of switches SW1 for switching the gate lines 86, and a first address decoder 94 for outputting a selection signal for selecting the switches SW1. An address signal is supplied from the cassette control unit 50 to the first address decoder 94.

Further, the charge held in each pixel 80 flows out to the signal line 88 through the TFTs 84 arranged in the column direction. This electric charge is amplified by the charge amplifier 96. A multiplexer 92 is connected to the charge amplifier 96 via a sample and hold circuit 98.

That is, the read charge of each column is input to the charge amplifier 96 of each column via each signal line 88. Each charge amplifier 96 includes an operational amplifier 100, a capacitor 102, and a switch 104. When the switch 104 is off, the charge amplifier 96 converts the charge signal input to one input terminal of the operational amplifier 100 into a voltage signal and outputs the voltage signal. The charge amplifier 96 amplifies and outputs the electrical signal with the gain set by the cassette control unit 50. Information relating to the gain of the charge amplifier 96 (gain setting information) is supplied from the system control unit 14 to the cassette control unit 50 via the detection device control unit 32. The cassette control unit 50 sets the gain of the charge amplifier 96 based on the supplied gain setting information.

The other input terminal of the operational amplifier 100 is connected to GND (ground potential) (ground). When all the TFTs 84 are turned on and the switch 104 is turned on, the charge accumulated in the capacitor 102 is discharged by the closed circuit of the capacitor 102 and the switch 104 and the charge accumulated in the pixel 80 is closed. It is swept out to GND (ground potential) via the switch 104 and the operational amplifier 100. The operation of turning on the switch 104 of the charge amplifier 96 to discharge the charge stored in the capacitor 102 and sweeping out the charge stored in the pixel 80 to GND (ground potential) is a reset operation (empty reading operation). Call it. In particular, the operation of sweeping out charges of all pixels to GND is referred to as an all-pixel reset operation. That is, in the reset operation, the voltage signal corresponding to the charge signal stored in the pixel 80 is discarded without being output to the multiplexer 92.

The multiplexer 92 includes a plurality of switches SW2 for switching the signal line 88 and a second address decoder 106 for outputting a selection signal for selecting the switch SW2. An address signal is supplied from the cassette control unit 50 to the second address decoder 106. An A / D converter 108 is connected to the multiplexer 92, and a radiation image converted into a digital signal by the A / D converter 108 is supplied to the cassette control unit 50.

The configurations of the second imaging unit 54B and the second readout circuit 78B are substantially the same as the configurations of the first imaging unit 54A and the first readout circuit 78A described above, and a duplicate description thereof will be omitted.

Note that the TFT 84 functioning as a switching element may be realized in combination with another imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. Furthermore, it can be replaced with a CCD (Charge-Coupled Device) image sensor that transfers charges while shifting the charges with a shift pulse corresponding to a gate signal referred to as a TFT.

As shown in FIG. 2, the cassette controller 50 of the radiation detector 30 includes a first address signal generator 110A for the first readout circuit 78A and a second address signal generator 110B for the second readout circuit 78B. A first image memory 112A, a second image memory 112B, and a cassette ID memory 114.

The first address signal generation unit 110A, for example, read control information for moving images (first read control information Sb1 described later) from the system control unit 14 and read control information (hereinafter referred to as energy sub) for energy subtraction (described later). Based on the third read control information Sb3), the address signal is supplied to the first address decoder 94 of the line scan driver 90 and the second address decoder 106 of the multiplexer 92 in the first read circuit 78A shown in FIG. . The first read control information Sb1 and the third read control information Sb3 include, for example, a progressive mode, an interlace mode (odd row read mode, even row read mode, second row read mode, third row read mode, etc.), binning mode (1 Information on the readout mode indicating the pixel / 4 pixel readout mode, 1 pixel / 6 pixel readout mode, 1 pixel / 9 pixel readout mode, etc.). For example, in the 1-pixel / 4-pixel readout mode, two adjacent gate lines are simultaneously activated (set to Von), and two adjacent signal lines are selected at the same time. In this mode, charges for pixels are mixed and read as one pixel. The first address signal generator 110A creates an address signal corresponding to the mode indicated by the first read control information Sb1 or the third read control information Sb3, and the first address decoder 94 and the multiplexer 92 of the line scan driver 90 Output to the second address decoder 106. The first read control information Sb1 and the third read control information Sb3 are created by the system control unit 14 based on, for example, an operation input from an operator, and are input to the cassette control unit 50 of the radiation detection apparatus 30.

The first readout control information Sb1 and the third readout control information Sb3 supplied from the system control unit 14 include imaging range information for designating an imaging range in addition to the information related to the above-described readout mode (readout mode information). . The imaging range information includes, for example, the address of the gate line 86 and the address of the signal line 88 included in the set imaging range when the operator sets the imaging range of a moving image, for example, using the input device 20 and the monitor 18. It is done. By using “0” as the first address of the first gate line 86 and the first signal line 88, operations such as address conversion are facilitated. Of course, the start address (number) and end address (number) of the gate line 86 included in the imaging range and the start address (number) and end address (number) of the signal line 88 may be used. If the readout mode information is, for example, an odd-numbered row readout mode (decimation), odd-numbered gate lines 86 are sequentially selected from among the gate lines 86 included in the imaging range of the first imaging unit 54A, and the first imaging unit is selected. The signal charges from the signal line 88 included in the imaging range of 54A are sequentially transferred toward the A / D converter 108 without being synthesized. If the readout mode information is, for example, a 1-pixel / 4-pixel readout mode (binning), for example, two gate lines 86 included in the imaging range are sequentially selected, and signal charges from the signal lines 88 included in the imaging range are combined. (In this case, signal charges from two adjacent signal lines 88 are combined), that is, signal charges for four pixels are combined and sequentially transferred to the A / D converter 108. Become.

The same applies to the second address signal generator 110B. For example, still image read control information (second read control information Sb2 described later) and energy sub read control information (described later) from the system control unit 14 are used. Based on the fourth read control information Sb4), an address signal is supplied to the first address decoder 94 of the line scan driver 90 and the second address decoder 106 of the multiplexer 92 in the second read circuit 78B shown in FIG.

The first image memory 112A stores the first radiation image D1 from the first readout circuit 78A of the radiation detector 42, and the second image memory 112B stores the second radiation image D2 from the second readout circuit 78B. . The cassette ID memory 114 stores cassette ID information for specifying the radiation detection apparatus 30. The transceiver 52 transmits the cassette ID information stored in the cassette ID memory 114 and the first radiation image D1 and the second radiation image D2 stored in the first image memory 112A and the second image memory 112B by wired communication or wireless communication. The data is transmitted to the system control unit 14 via the detection device control unit 32.

As shown in FIG. 13, the detection device control unit 32 includes a first image input / output control unit 116 A that controls input and output of the first radiation image D 1 from the radiation detection device 30, and a second image from the radiation detection device 30. And a second image input / output control unit 116B that controls input and output of the radiation image D2.

And the system control part 14 of this radiographic imaging system 10 has the moving image imaging | photography process part 118, the still image imaging | photography process part 120, the energy sub imaging | photography process part 122, and the synchronizer 124, as shown in FIG. .

For example, the moving image shooting processing unit 118 sets the irradiation energy for moving image shooting corresponding to the imaging region based on the operation input of the moving image shooting request by the operator or the input of the moving image shooting request from another device, and the moving image is set. The radiation imaging for obtaining is controlled.

The moving image shooting processing unit 118 includes a first parameter setting unit 126A for moving images, a first parameter history storage unit 128A, and a moving image transfer unit 130.

The first parameter setting unit 126A stores the first parameter history for moving images when new parameters (radiation irradiation energy, frame rate, etc.) are set by an operation input from the operator during moving image shooting. The irradiation energy and frame rate newly set in the unit 128A are stored as the latest parameters. In particular, when the irradiation energy is newly set, the first irradiation energy setting information Sa1 including information on the newly set irradiation energy (information such as tube voltage, tube current, irradiation time) is supplied to the radiation irradiation system 28. If the readout mode and the imaging range are newly set, the first readout control information Sb1 including the newly set readout mode information and imaging range information is detected via the detection device control unit 32. Output to device 30.

The first parameter history storage unit 128A stores the irradiation energy and the frame rate set over the predetermined period from the present time among the irradiation energy and the frame rate set so far.

The moving image transfer unit 130 receives the first radiation images D1 sequentially supplied from the radiation detection device 30 (the first imaging unit 54A and the first readout circuit 78A of the radiation detector 42) via the detection device control unit 32, Transfer to console 16. The console 16 displays the first radiation image D1 sequentially transferred on the monitor 18. Thereby, the moving image of the first radiation image D1 is displayed on the monitor 18.

The still image capturing processing unit 120 sets irradiation energy for still image capturing corresponding to, for example, an imaging region based on, for example, an operation input of a still image capturing request by an operator or an input of a still image capturing request from another device ( Radiation imaging for obtaining a still image is executed and controlled with higher energy than for moving images).

The still image shooting processing unit 120 includes a second parameter setting unit 126B for still images, a second parameter history storage unit 128B, and a still image transfer unit 132. The second parameter history storage unit 128B has the same configuration as the first parameter history storage unit 128A described above.

Similar to the first parameter setting unit 126A described above, the second parameter setting unit 126B sets new parameters (irradiation energy of the radiation 26, frame rate, etc.) in response to an operation input from the operator or the like during still image shooting. If there is, the irradiation energy and frame rate newly set in the second parameter history storage unit 128B for still images are stored as the latest parameters. In particular, when the irradiation energy is newly set, the second irradiation energy setting information Sa2 including information on the newly set irradiation energy (information such as tube voltage, tube current, and irradiation time) is input to the radiation irradiation system 28. When the read mode and the imaging range are newly set, the radiation detection device receives the second readout control information Sb2 including the newly set readout mode information, imaging range information, and the like via the detection device control unit 32. Output to 30.

The still image transfer unit 132 receives the second radiation image D2 supplied from the radiation detection device 30 (the second imaging unit 54B and the second readout circuit 78B of the radiation detector 42) via the detection device control unit 32, and Transfer to console 16. The console 16 displays the transferred second radiation image D2 on the monitor 18. As a result, a still image of the radiation image is displayed on the monitor 18.

The energy sub imaging processing unit 122 sets the irradiation energy for subtraction imaging corresponding to the imaging region, for example, based on the operation input of the energy sub imaging request by the operator or the input of the energy sub imaging request from another device (from the moving image). (High energy) and control the execution of radiography to obtain an energy sub-image.

The energy sub imaging processing unit 122 includes an energy sub third parameter setting unit 126C, a third parameter history storage unit 128C, an energy sub moving image creating unit 134 (energy subtraction moving image generating unit), and an energy sub moving image transfer unit 136. Have The third parameter history storage unit 128C has the same configuration as the first parameter history storage unit 128A described above.

Similar to the first parameter setting unit 126A described above, the third parameter setting unit 126C newly sets parameters (radiation irradiation energy, frame rate, etc.) by an operation input from the operator or the like at the time of energy sub imaging. In this case, the irradiation energy and frame rate newly set in the third parameter history storage unit 128C are stored as the latest parameters. In particular, when the irradiation energy is newly set, the third irradiation energy setting information Sa3 including information on the newly set irradiation energy (information such as tube voltage, tube current, irradiation time) is supplied to the radiation irradiation system 28. If the readout mode and the imaging range are newly set, the radiation detection device receives the third readout control information Sb3 including the newly set readout mode information and imaging range information through the detection device control unit 32. Output to 30.

Based on the third readout control information Sb3 from the energy sub imaging processing unit 122, the synchronization unit 124 sets the continuous imaging timing in the second imaging unit 54B to the continuous imaging times in the first imaging unit 54A. Information (fourth readout control information Sb4) for synchronizing with the imaging timing is created, and the fourth readout control information Sb4 is output to the radiation detection apparatus 30 via the detection apparatus control unit 32.

The synchronization unit 124 includes an information table 138 in which information on the spatial resolution of the first imaging unit 54A and the second imaging unit 54B, for example, information such as the coefficients kv and kh described above, and a compression of the gate line 86 set in advance. A read control information creating unit 140 that creates the fourth read control information Sb4 based on the method information (information indicating decimation and binning), the third read control information Sb3, the above spatial resolution information, the compression method information, and the like. And have.

The readout control information creation unit 140 creates imaging range information corresponding to the second imaging unit 54B based on the imaging range information included in the third readout control information Sb3. Specifically, the coefficient (kv) is multiplied by the address (or start address, end address) of the gate line 86 included in the imaging range, and the coefficient is calculated for the address (or start address, end address) of the signal line 88 included in the imaging range. By multiplying kh, imaging range information corresponding to the second imaging unit 54B can be obtained. Further, the read control information creating unit 140 creates read mode information based on information on a preset compression method. For example, when the compression method indicates thinning, information indicating the thinning out coefficient kv-1 for the gate line 86 and the binning of coefficient kh for the signal line 88 is created. For example, when the compression technique indicates binning, information indicating kv bins for the gate line 86 and kh bins for the signal line 88 is generated.

The synchronization unit 124 outputs the fourth readout control information Sb4 including the imaging range information, readout mode information, and the like created by the readout control information creation unit 140 to the radiation detection device 30 via the detection device control unit 32.

On the other hand, the energy sub moving image creation unit 134 in the energy sub imaging processing unit 122 is sequentially supplied from the radiation detection device 30 (the first imaging unit 54A and the first readout circuit 78A of the radiation detector 42) via the detection device control unit 32. Weighting of the first radiation image D1 and the second radiation image D2 sequentially supplied from the radiation detection device 30 (the second imaging unit 54B and the second readout circuit 78B of the radiation detector 42) via the detection device control unit 32 A subtraction process is performed to create a radiation image (energy sub image Ds) for energy sub moving image capturing. The energy sub moving image transfer unit 136 transfers the energy sub images Ds that are sequentially generated to the console 16. The console 16 displays the energy sub-image Ds sequentially transferred on the monitor 18. As a result, the moving image of the energy sub-image Ds is displayed on the monitor 18.

Next, the processing operation of the radiation image capturing system 10 will be described with reference to FIGS.

First, still image shooting will be described with reference to FIGS. First, in step S1 of FIG. 14, the second parameter setting unit 126B of the still image capturing processing unit 120 determines whether or not new parameters (irradiation energy of radiation 26, gain, readout mode, etc.) are set. . For example, when the operator newly sets a parameter, the process proceeds to step S2, and the irradiation energy newly set in the second parameter history storage unit 128B is stored as the latest parameter.

In step S3, the second irradiation energy setting information Sa2 including the latest irradiation energy information (tube voltage, tube current, irradiation time, etc.) is output to the radiation irradiation system 28. The radiation source control unit 36 of the radiation irradiation system 28 sets the irradiation energy output from the radiation source 34 to a new irradiation energy based on the second irradiation energy setting information Sa2 from the system control unit 14.

In step S4, the second reading control information Sb2 including the latest imaging range information and reading mode information is output to the radiation detecting device 30 via the detecting device control unit 32. The cassette control unit 50 of the radiation detection apparatus 30 supplies the input second read control information Sb2 to the second address signal generation unit 110B.

In step S5, the system control unit 14 determines whether or not the exposure switch has been operated. When the exposure switch is operated, the process proceeds to step S6, and the system control unit 14 outputs an exposure start signal Sc (see FIG. 15) to the radiation irradiation system 28. The radiation source control unit 36 of the radiation irradiation system 28 controls the radiation source 34 based on the input of the exposure start signal Sc from the system control unit 14, and emits radiation with the irradiation energy set from the radiation source 34. Irradiate.

In step S 7, the system control unit 14 outputs an exposure notification Sd (see FIG. 15) indicating that the radiation irradiation system 28 has started exposure to the detection device control unit 32.

In step S8, the detection device controller 32 outputs an operation start signal Se (see FIG. 15) indicating charge accumulation and charge reading to the radiation detection device 30 based on the input of the exposure notification Sd.

In step S9, the radiation detection apparatus 30 performs charge accumulation and charge read based on the input of the operation start signal Se from the detection apparatus control unit 32. That is, the radiation 26 that has passed through the subject 24 is temporarily converted into visible light, for example, by the scintillator of the second imaging unit 54B, and the visible light is photoelectrically converted in each pixel 80 of the second imaging unit 54B according to the amount of light. An amount of charge is accumulated. Then, a second synchronization signal Sf2 (for example, vertical synchronization signal: see FIG. 15) is output at the start of the reading period of the second reading circuit 78B, and is input to the second image input / output control unit 116B of the detection device control unit 32. The The second image input / output control unit 116B synchronizes the reception timing of the second radiation image D2 with the output timing of the second radiation image D2 from the radiation detection device 30 based on the input of the second synchronization signal Sf2.

In the subsequent readout period, the second address signal generator 110B creates an address signal corresponding to the supplied second readout control information Sb2 (imaging range information, readout mode information, etc.), and the line in the second readout circuit 78B. The data is output to the first address decoder 94 of the scan driver 90 and the second address decoder 106 of the multiplexer 92. The second readout circuit 78B reads out charges in accordance with the second readout control information Sb2, and outputs the second radiation image D2 for a still image by using, for example, the FIFO method using the second image memory 112B. The second radiation image D2 from the radiation detection device 30 is supplied to the system control unit 14 via the second image input / output control unit 116B of the detection device control unit 32.

In step S10, the still image transfer unit 132 of the still image capturing processing unit 120 transfers the supplied second radiographic image D2 for still images to the console 16. The console 16 stores the transferred second radiation image D2 in the frame memory and displays it on the monitor 18 as a still image.

In step S11, the system control unit 14 determines whether or not there is a still image shooting end request (for example, a moving image shooting request or an energy sub moving image shooting request). If there is no request for termination of still image shooting, the process returns to step S1, and the processes in and after step S1 are repeated. On the other hand, when it is determined in step S11 that there is a request to end still image shooting, still image shooting ends.

In the example of FIG. 15, for example, when the irradiation energy, the readout mode, the imaging range, and the like are changed, for example, by an operation input by an operator, for example, before the radiation imaging start time t0, the second parameter setting unit 126B The second irradiation energy setting information Sa2 including the information of the newly set irradiation energy is output to the radiation irradiation system 28, and the second reading control information Sb2 including the newly set photographing range information, reading mode information, and the like is output. The data is output to the radiation detection device 30 via the detection device control unit 32. The cassette control unit 50 of the radiation detection apparatus 30 supplies the input second read control information Sb2 to the second address signal generation unit 110B. Thereby, the radiation irradiation system 28 is set to a new irradiation energy, and the second readout circuit 78B is set to a new imaging range, a readout mode, and the like.

After that, at the radiation imaging start time t0, the system control unit 14 outputs an exposure start signal Sc to the radiation irradiation system 28, and performs an exposure notification Sd to the detection device control unit 32, whereby the system control unit 14 is notified. Then, the second radiation image D2 obtained by still image shooting is supplied. The system control unit 14 transfers the supplied second radiation image D2 to the console 16 and displays it on the monitor 18 as a still image.

Next, movie shooting will be described with reference to FIGS. First, in step S101 of FIG. 16, the system control unit 14 stores an initial value (= 1) in the counter k of the number of photographing times.

In step S102, the first parameter setting unit 126A determines whether or not parameters (irradiation energy of the radiation 26, frame rate, imaging range, readout mode, etc.) are newly set. For example, when the operator newly sets a parameter, the process proceeds to step S103, and the irradiation energy, frame rate, and the like newly set in the first parameter history storage unit 128A are stored as the latest parameters.

When the irradiation energy is newly set, in the next step S104, the first irradiation energy setting information Sa1 including information of the newly set irradiation energy (information such as tube voltage, tube current, irradiation time) is radiated. Output to the irradiation system 28. The radiation source control unit 36 of the radiation irradiation system 28 sets the irradiation energy output from the radiation source 34 to a new irradiation energy based on the first irradiation energy setting information Sa1 from the system control unit 14.

When the shooting range, the reading mode, and the like are newly set, in the next step S105, the first reading control information Sb1 including the newly set shooting range information and reading mode information is sent via the detection device control unit 32. Output to the radiation detector 30. The cassette control unit of the radiation detection apparatus 30 supplies the input first read control information Sb1 to the first address signal generation unit 110A.

In step S106, the system control unit 14 determines whether or not a time corresponding to the latest frame rate Fr has elapsed since the start of the previous radiation imaging. When the value of the counter k is an initial value or when the time corresponding to the latest frame rate Fr has elapsed since the start of the previous radiation imaging, the system control unit 14 proceeds to the next step S107, and the system control unit 14 At the start of imaging, an exposure start signal Sc (see FIG. 17) is output to the radiation irradiation system 28. The radiation source control unit 36 of the radiation irradiation system 28 controls the radiation source 34 based on the input of the exposure start signal Sc from the system control unit 14, and emits radiation with the irradiation energy set from the radiation source 34. Irradiate.

In step S108, the system control unit 14 outputs to the detection device control unit 32 an exposure notification Sd (see FIG. 17) indicating that the radiation irradiation system 28 has started exposure.

In step S109, the detection device controller 32 outputs an operation start signal Se (see FIG. 17) indicating charge accumulation and charge reading to the radiation detection device 30 based on the input of the exposure notification Sd.

In step S110, the radiation detection apparatus 30 performs charge accumulation and charge read based on the input of the operation start signal Se from the detection apparatus control unit 32. That is, the radiation 26 transmitted through the subject 24 is temporarily converted into visible light, for example, by the scintillator of the first imaging unit 54A, and the visible light is photoelectrically converted in each pixel 80 of the first imaging unit 54A according to the amount of light. An amount of charge is accumulated. Then, a first synchronization signal Sf1 (for example, a vertical synchronization signal: see FIG. 17) is output at the start of the reading period in the first reading circuit 78A, and is input to the first image input / output control unit 116A of the detection device control unit 32. The The first image input / output control unit 116A synchronizes the reception timing of the first radiation image D1 with the output timing of the first radiation image D1 from the radiation detection device 30 based on the input of the first synchronization signal Sf1.

In the subsequent readout period, the first address signal generator 110A creates an address signal corresponding to the supplied first readout control information (imaging range information, readout mode information, etc.), and performs line scanning in the first readout circuit 78A. The data is output to the first address decoder 94 of the driving unit 90 and the second address decoder 106 of the multiplexer 92. The first readout circuit 78A reads out charges in accordance with the first readout control information Sb1, and outputs the first radiation image D1 for moving image using, for example, the FIFO method using the first image memory 112A. The first radiation image D1 from the radiation detection device 30 is supplied to the system control unit 14 via the detection device control unit 32.

In step S111, the system control unit 14 transfers the supplied first radiation image D1 for moving image to the console 16. The console 16 stores the transferred first radiation image D1 in the frame memory and displays it on the monitor 18 as a radiation image obtained by the k-th radiation imaging, that is, a k-th radiation image.

In step S112, the value of the counter k is updated by +1.

In step S113, the system control unit 14 determines whether or not there is a moving image shooting end request (for example, a still image shooting request or an energy sub moving image shooting request). If there is no moving image shooting end request, the process returns to step S102, and the processes in and after step S102 are repeated. Thereby, the moving image of the radiation image at the set frame rate is displayed on the monitor 18. On the other hand, when it is determined in step S113 that there is an end request for moving image shooting, the moving image shooting ends.

In the example of FIG. 17, for example, the irradiation energy and readout are performed, for example, by an operation input of an operator, for example, before the start time tn−1 of the N−1 (N = 2, 3,...) Radiation imaging. When the mode is changed, the first parameter setting unit 126A outputs the first irradiation energy setting information Sa1 including information on the newly set irradiation energy to the radiation irradiation system 28, and the newly set imaging range information. The first readout control information Sb1 including the readout mode information is output to the radiation detection apparatus 30 via the detection apparatus control unit 32. The cassette control unit 50 of the radiation detection apparatus 30 supplies the input first read control information Sb1 to the first address signal generation unit 110A. Thereby, the radiation irradiation system 28 is set to a new irradiation energy, and the first readout circuit 78A is set to a new imaging range, a readout mode, and the like.

Thereafter, at the start time tn−1 of the (N−1) th radiography, the system control unit 14 outputs the exposure start signal Sc to the radiation irradiation system 28 and performs the exposure notification Sd to the detection device control unit 32. Thus, the first radiographic image D1 obtained by the (N-1) th radiography is supplied to the system control unit 14. The system control unit 14 transfers the supplied first radiation image D1 to the console 16 and displays it on the monitor 18 as a radiation image of the (N−1) th frame.

Similarly, the system control unit 14 outputs an exposure start signal Sc to the radiation irradiation system 28 at the start time tn of the N-th radiography in which the latest frame rate Fr has elapsed from the start time tn−1 described above. By performing the exposure notification Sd to the detection device control unit 32, the first radiographic image D1 obtained by the N-th radiography is supplied to the system control unit 14. The system control unit 14 transfers the supplied first radiographic image D1 to the console 16 and displays it on the monitor 18 as an Nth frame radiographic image. By repeating these operations, the moving image of the radiation image is displayed on the monitor 18.

Next, energy-sub moving image shooting will be described with reference to FIGS. First, in step S201 in FIG. 18, the system control unit 14 stores an initial value (= 1) in the counter k of the number of photographing times.

In step S202, the third parameter setting unit 126C determines whether or not parameters (radiation irradiation energy, frame rate, imaging range, readout mode, etc.) are newly set. For example, when the operator newly sets a parameter, the process proceeds to step S203, and the irradiation energy, frame rate, and the like newly set in the third parameter history storage unit 128C are stored as the latest parameters.

When the irradiation energy is newly set, in the next step S204, the third irradiation energy setting information Sa3 including information of the newly set irradiation energy (information such as tube voltage, tube current, irradiation time) is radiated. Output to the irradiation system 28. The radiation source control unit 36 of the radiation irradiation system 28 sets the irradiation energy output from the radiation source 34 to a new irradiation energy based on the third irradiation energy setting information Sa3 from the system control unit 14.

When the shooting range, the reading mode, and the like are newly set, in the next step S205, the third parameter setting unit 126C obtains the third reading control information Sb3 including the newly set shooting range information and reading mode information. The data is output to the radiation detection device 30 via the detection device control unit 32. The cassette control unit of the radiation detection apparatus 30 supplies the input third read control information Sb3 to the first address signal generation unit 110A.

In step S206, based on the third readout control information Sb3, the synchronization unit 124 changes the continuous imaging timing at the second imaging unit 54B to the continuous imaging timing at the first imaging unit 54A. Information for synchronization (fourth read control information Sb4) is created. Next, in step S207, the created fourth readout control information Sb4 is output to the radiation detection apparatus 30 via the detection apparatus control unit 32. Since an example of a method for creating the fourth read control information Sb4 has been described above, a duplicate description thereof is omitted here.

The system control unit 14 outputs the created fourth readout control information Sb4 to the radiation detection device 30 via the detection device control unit 32. The cassette control unit 50 of the radiation detection apparatus 30 supplies the input fourth read control information Sb4 to the second address signal generation unit 110B.

In step S208, the system control unit 14 determines whether or not a time corresponding to the latest frame rate Fra in the energy sub imaging has elapsed since the start of the previous radiation imaging. When the value of the counter k is an initial value or when a time corresponding to the latest frame rate Fra has elapsed since the start of the previous radiation imaging, the system control unit 14 proceeds to the next step S209, and the system control unit 14 At the start of imaging, an exposure start signal Sc is output to the radiation irradiation system 28. The radiation source control unit 36 of the radiation irradiation system 28 controls the radiation source 34 based on the input of the exposure start signal Sc from the system control unit 14, and emits radiation with the irradiation energy set from the radiation source 34. Irradiate.

In step S210, the system control unit 14 outputs to the detection device control unit 32 an exposure notification Sd (see FIG. 19) indicating that the irradiation start has been performed on the radiation irradiation system 28.

In step S211, the detection device controller 32 outputs an operation start signal Se (see FIG. 19) indicating charge accumulation and charge reading to the radiation detection device 30 based on the input of the exposure notification Sd.

In step S212, the radiation detection apparatus 30 performs charge accumulation and charge reading based on the input of the operation start signal Se from the detection apparatus control unit 32. That is, of the radiation 26 that has passed through the subject 24, the low-energy component radiation is once converted into visible light by the scintillator of the first imaging unit 54A, and the visible light is photoelectrically converted in each pixel 80 of the first imaging unit 54A. Thus, an amount of electric charge corresponding to the amount of light is accumulated. Similarly, the high-energy component radiation is once converted into visible light by the scintillator of the second imaging unit 54B, and the visible light is photoelectrically converted in each pixel 80 of the second imaging unit, and an amount of charge corresponding to the amount of light is generated. Accumulated.

Then, the first synchronization signal Sf1 (for example, vertical synchronization signal: see FIG. 19) is output at the start of the reading period in the first reading circuit 78A, and is input to the first image input / output control unit 116A of the detection device control unit 32. The The first image input / output control unit 116A synchronizes the reception timing of the first radiation image D1 with the output timing of the first radiation image D1 from the radiation detection device 30 based on the input of the first synchronization signal Sf1.

Similarly, a second synchronization signal Sf2 (for example, vertical synchronization signal: see FIG. 19) is output at the start of the reading period in the second reading circuit 78B, and is input to the second image input / output control unit 116B of the detection device control unit 32. Is done. The second image input / output control unit 116B synchronizes the reception timing of the second radiation image D2 with the output timing of the second radiation image D2 from the radiation detection device 30 based on the input of the second synchronization signal Sf2.

In the subsequent readout period, the first address signal generator 110A creates an address signal corresponding to the supplied third readout control information Sb3 (imaging range information, readout mode information, etc.), and the line in the first readout circuit 78A. The data is output to the first address decoder 94 of the scan driver 90 and the second address decoder 106 of the multiplexer 92. Similarly, the second address signal generator 110B creates an address signal corresponding to the supplied fourth read control information Sb4 (imaging range information, read mode information, etc.), and performs line scanning drive in the second read circuit 78B. The data is output to the first address decoder 94 of the unit 90 and the second address decoder 106 of the multiplexer 92.

The first readout circuit 78A reads out charges in accordance with the third readout control information Sb3, and outputs the first radiation image D1 with low energy using, for example, the FIFO method using the first image memory 112A. Similarly, the second readout circuit 78B reads out charges in accordance with the fourth readout control information Sb4, and outputs the second radiation image D2 with high energy using, for example, the FIFO method using the second image memory 112B.

In the first readout circuit 78A, for example, the gate lines 86 included in the imaging range are selected one by one, and the signal charges from the signal lines 88 included in the imaging range are sequentially synthesized toward the A / D converter 108. Forward. On the other hand, in the second readout circuit 78B, in the case of thinning, among the gate lines 86 included in the imaging range, the gate line of coefficient kv is sequentially selected in a skipped manner, and further, for each coefficient kh included in the imaging range. The signal charges from the signal lines 88 are combined and sequentially transferred to the A / D converter 108. Thereby, the imaging timing and frame rate in the first imaging unit 54A can be synchronized with the imaging timing and frame rate in the second imaging unit 54B.

The first radiation image D1 with low energy and the second radiation image D2 with high energy from the radiation detection device 30 are passed through the first image input / output control unit 116A and the second image input / output control unit 116B of the detection device control unit 32. To the system control unit 14.

In step S213, the energy sub moving image creating unit 134 performs weighted subtraction processing between the first radiation image D1 with low energy and the second radiation image D2 with high energy supplied from the radiation detection device 30 via the detection device control unit 32. Then, the energy sub-image Ds is created.

In step S214, the energy sub moving image transfer unit 136 transfers the generated energy sub image Ds to the console 16. The console 16 stores the transferred energy sub-image Ds in the frame memory and displays it on the monitor 18 as the energy sub-image Ds obtained by the k-th radiography, that is, the k-th energy sub-image Ds.

In step S215, the value of the counter k is updated by +1.

In step S216, the system control unit 14 determines whether there is an energy sub moving image shooting end request (for example, a still image shooting request or a moving image shooting request). If there is no request to end the energy-sub moving image shooting, the process returns to step S202, and the processes in and after step S202 are repeated. As a result, the moving image of the energy sub-image Ds at the set frame rate is displayed on the monitor 18. On the other hand, in step S216, when it is determined that there is a request to end the energy sub moving image shooting, the energy sub moving image shooting ends.

In the example of FIG. 19, for example, the irradiation energy and readout are performed, for example, by an operation input of the operator, for example, at the stage before the start time tn-1 of the N-1 (N = 2, 3,. When the mode is changed, the third parameter setting unit 126C outputs the third irradiation energy setting information Sa3 including information on the newly set irradiation energy to the radiation irradiation system 28, and the newly set imaging range information. And third readout control information Sb3 including readout mode information is output to the radiation detection apparatus 30 via the detection apparatus control section 32. The cassette control unit 50 of the radiation detection apparatus 30 supplies the input third read control information Sb3 to the first address signal generation unit 110A. Thereby, the radiation irradiation system 28 is set to a new irradiation energy, and the first readout circuit 78A is set to a new imaging range, a readout mode, and the like.

On the other hand, based on the third readout control information Sb3, the synchronization unit 124 synchronizes a plurality of consecutive imaging timings in the second imaging unit 54B with a plurality of consecutive imaging timings in the first imaging unit 54A. Information (fourth read control information Sb4) is generated, and the fourth read control information Sb4 is output to the radiation detection apparatus 30 via the detection apparatus control unit 32. The cassette control unit 50 of the radiation detection apparatus 30 supplies the input fourth read control information Sb4 to the second address signal generation unit 110B. As a result, the second readout circuit 78B is set to a new imaging range and readout mode for synchronizing with the first imaging unit 54A.

Thereafter, at the start time tn−1 of the (N−1) th radiography, the system control unit 14 outputs the exposure start signal Sc to the radiation irradiation system 28 and performs the exposure notification Sd to the detection device control unit 32. Thus, two radiographic images obtained by the N-1th radiography, that is, a first radiographic image D1 with low energy and a second radiographic image D2 with high energy are supplied to the system control unit 14. The system control unit 14 performs the weighted subtraction process on the supplied first radiation image D1 and second radiation image D2 to create an energy sub-image Ds. Then, the created energy sub image Ds is transferred to the console 16 and displayed on the monitor 18 as the energy sub image Ds of the (N−1) th frame.

Similarly, at the start time tn of the N-th radiography in which the latest frame rate Fra in the energy sub-imaging has elapsed from the start time tn−1, the system control unit 14 sends the exposure start signal Sc to the radiation irradiation system 28. By outputting and performing exposure notification Sd to the detection device control unit 32, the system control unit 14 is given two radiographic images (first radiographic image D1 with low energy and second radiographic image with high energy) by the N-th radiography. D2) is supplied. The system control unit 14 creates an energy sub-image Ds from the two supplied radiographic images, transfers it to the console 16, and displays it on the monitor 18 as the energy sub-image Ds of the Nth frame. By repeating these operations, the monitor 18 displays the moving image of the energy sub-image Ds.

Thus, in the radiographic imaging system 10, the radiation irradiation system 28 having the radiation source 34, the radiation image output system 29 that converts the radiation 26 from the radiation source 34 that has passed through the subject 24 into a radiation image, and outputs the radiation image. , And a radiographic imaging system having a radiographic imaging system 12 that executes and controls radiographic imaging at a set imaging timing. The first imaging unit 54A and the second imaging unit 54B that have different sensitivity characteristics and convert radiation into a radiographic image are provided, and the system control unit 14 includes a plurality of continuous first imaging units 54A and second imaging units 54B. Since the synchronization unit 124 that synchronizes the imaging timing of the image is included, the energy that could only be realized for still image use until now The Bed shooting can widen the applications to the Enesabu shooting video, it can contribute to the spread of the radiation image capturing system 10 which performs Enesabu shooting. Moreover, since the subtraction image processing can be performed by one exposure, the energy sub-image Ds can be created without being affected by the body movement of the subject 24, and the moving image of the energy sub-image Ds with good image quality can be created. Obtainable.

By the way, depending on specific examples of the first imaging unit 54A and the second imaging unit 54B, the charge accumulation period in the first imaging unit 54A and the charge accumulation period in the second imaging unit 54B overlap at least partly (all Period or part of the period).

As the first case, for example, in the first to fifth embodiments shown in FIGS. 5A to 6B, the twelfth to fourteenth embodiments shown in FIGS. 9A to 10A, and the seventeenth embodiment shown in FIG. 11A, one sensor is used. Since the substrate 56 is used, there is almost no time difference in the arrival time of visible light to each pixel of the first imaging unit 54A and each pixel of the second imaging unit 54B. For example, the time difference is only shorter than the pulse width of the reference clock used in the system. Therefore, in this case, as shown in FIG. 20A, the start time tb1 of the charge accumulation period Ta1 in the first imaging unit 54A and the start time tb2 of the charge accumulation period Ta2 in the second imaging unit 54B from the imaging start time ta. Will be synchronized. When the vertical synchronization signals (Sf1, Sf2) are output at a time td after a certain period of time has elapsed from the photographing start time ta, the output time td of the vertical synchronization signals (Sf1, Sf2) is the end of the charge accumulation periods Ta1 and Ta2. Therefore, the end time tc1 of the charge accumulation period Ta1 in the first imaging unit 54A and the end time tc2 of the charge accumulation period Ta2 in the second imaging unit 54B are synchronized.

As a second case, in the sixth to eleventh modes shown in FIGS. 7A to 8C, the fifteenth mode shown in FIG. 10B, and the eighteenth mode shown in FIG. 11B, the first sensor substrate 56A is made incident with radiation 26. Since the second sensor substrate 56B is installed on the side opposite to the incident side of the radiation 26 and the first imaging unit 54A detects visible light by the ISS method, each pixel of the first imaging unit 54A and A time difference Δt longer than the pulse width of the reference clock occurs in the arrival time of the visible light to each pixel of the second imaging unit 54B. Therefore, in this case, as shown in FIG. 20B, the start time tb1 of the charge accumulation period Ta1 in the first imaging unit 54A and the start time tb2 of the charge accumulation period Ta2 in the second imaging unit 54B from the imaging start time ta. The time difference Δt is shifted. When the vertical synchronization signals (Sf1, Sf2) are output after a certain period of time has elapsed from the photographing start time ta, the output time td of the vertical synchronization signals (Sf1, Sf2) is the end time of the charge accumulation time. The end time tc1 of the charge accumulation period Ta1 in the first imaging unit 54A and the end time tc2 of the charge accumulation period Ta2 in the second imaging unit 54B are synchronized. In this case, the charge accumulation period Ta2 in the second imaging unit 54B is shortened by the time difference Δt described above.

As a third case, as shown in FIG. 20C, when the output time td of the vertical synchronization signal (Sf2) in the second imaging unit 54B is delayed in anticipation of the above time difference Δt, the second imaging unit 54B Since the end time tc2 of the charge accumulation period Ta2 is shifted by the time difference Δt described above, the charge accumulation period Ta1 in the first imaging unit 54A and the charge accumulation period Ta2 in the second imaging unit 54B are the same.

As a fourth case, conversely, in the sixteenth mode shown in FIG. 10C, the second sensor substrate 56B is installed on the incident side of the radiation 26, and the first sensor substrate 56A is installed on the opposite side of the incident side of the radiation 26. Since the second imaging unit 54B detects visible light by the ISS method, the pulse width of the reference clock depends on the arrival time of the visible light to each pixel of the first imaging unit 54A and each pixel of the second imaging unit 54B. Longer time difference Δt occurs. Therefore, in this case, as shown in FIG. 21A, the start time tb1 of the charge accumulation period Ta1 in the first imaging unit 54A and the start time tb2 of the charge accumulation period Ta2 in the second imaging unit 54B from the imaging start time ta. The time difference Δt is shifted. When the vertical synchronization signals (Sf1, Sf2) are output when a certain period has elapsed from the photographing start time ta, the output time of the vertical synchronization signals (Sf1, Sf2) is the end time of the charge accumulation time. The end time tc1 of the charge accumulation period Ta1 in the first imaging unit 54A and the end time tc2 of the charge accumulation period Ta2 in the second imaging unit 54B are synchronized. In this case, the charge accumulation period Ta1 in the first imaging unit 54A is shortened by the time difference Δt described above.

As a fifth case, as shown in FIG. 21B, when the output time td of the vertical synchronization signal (Sf1) from the first imaging unit 54A is delayed in anticipation of the above-described time difference Δt, the first imaging unit 54A Since the end point tc1 of the charge accumulation period Ta1 is shifted by the above-described time difference Δt, the charge accumulation period Ta1 in the first imaging unit 54A and the charge accumulation period Ta2 in the second imaging unit 54B are the same.

In the first case described above, since the charge accumulation period Ta1 in the first imaging unit 54A and the charge accumulation period Ta2 in the second imaging unit 54B are the same, the image quality of the energy sub-image Ds can be improved. In addition, since the output time points of the vertical synchronization signals (Sf1, Sf2) can be synchronized, it is not necessary to set an extra latch time when transferring the radiation image, and the transfer speed of the radiation image can be improved.

In the third and fifth cases described above, the charge accumulation period Ta1 in the first imaging unit 54A and the charge accumulation period Ta2 in the second imaging unit 54B are the same, so that the image quality of the energy sub-image Ds is improved. Can do.

In the second and fourth cases described above, the time difference Δt described above occurs between the charge accumulation period Ta1 in the first imaging unit 54A and the charge accumulation period Ta2 in the second imaging unit 54B, but the vertical synchronization signal (Sf1, Since the output time of Sf2) can be synchronized, the transfer speed of the radiation image can be improved.

In the present embodiment, the radiation irradiation system 28 may include a plurality of radiation sources 34 as shown in FIGS. 22A to 22C. In this case, among the plurality of radiation sources 34, for example, one radiation source 34 may perform radiography for moving images, and two or more radiation sources 34 may perform radiography for still images. As a result, the radiation 26 can be irradiated with high followability even at a fast time interval of 1/60 seconds to 1/15 seconds, and a moving image display of the radiation image can be realized. Moreover, since the irradiation energy for moving images is set for each radiation source 34, and at the time of still image shooting, two or more radiation sources may be selected and set to the irradiation energy necessary for still images. Thus, it is possible to quickly switch from radiography to radiography for still images. Furthermore, in radiography for moving images, radiography may be performed with one radiation source selected randomly or in sequence for each radiography. In this case, it is preferable not to select an adjacent radiation source between frames for heat countermeasures. Even in radiography for still images, radiography may be performed with two or more radiation sources 34 selected randomly or as one cluster for each radiography.

Furthermore, for example, when two radiation sources 34 shown in FIG. 22A are used, high-energy radiation 26 may be emitted from one radiation source 34, and low-energy radiation 26 may be emitted from the other radiation source 34.

Thereby, for example, it is possible to perform energy sub moving image shooting in the following two modes (first mode and second mode).

[First aspect]
For example, in angiography (angiography), energy sub-moving imaging is performed by simultaneously irradiating radiation 26 of different energy from two radiation sources 34 using a contrast agent.

In general, angiography is a method of inspecting blood vessels and tumors by injecting an iodine contrast agent into the blood vessel and performing radiography using the fact that the iodine contrast agent is selectively taken into the tumor. is there.

And in this 1st aspect, the radiation absorption characteristic of an iodine, ie, the high absorption factor with respect to the radiation 26 with an energy of 33 keV or more, is utilized, and the high energy radiation 26 with less than 33 keV and the high energy radiation 26 with 33 keV or more. Are simultaneously obtained, for example, an energy sub moving image obtained by separating a blood vessel image from an image of a bone or the like is obtained. Bone has a high absorption rate for radiation 26 of less than 33 keV.

In the first aspect, the following effects are produced.
(1-a) It becomes easier to see blood vessels and tumors that are difficult to see because they are hidden behind bones.
(1-b) Since two types of radiations 26 having different energies are irradiated in the same phase, an image (moving image) having no deviation can be obtained.
(1-c) Since it is not necessary to acquire an image that does not use a contrast agent, the exposure dose to the subject 24 can be reduced.

[Second embodiment]
Recently, a radiographic imaging apparatus that acquires a three-dimensional image without compressing the breast has been proposed (see Japanese Patent Application Laid-Open Nos. 2009-22601 and 2008-93135). An angiography similar to that in the first aspect described above is performed using such a radiographic imaging device. Specifically, among the radiation irradiation system and the radiation detection apparatus that rotate around the breast, the radiation irradiation system irradiates radiation 26 having different energy simultaneously from two radiation sources 34 as shown in FIG. 9A, for example. As the radiation detection device, the radiation detection device 30 according to the present embodiment is applied, and the radiation source 34 and the radiation detection device 30 are controlled by the system control unit 14 according to the present embodiment. Energy sub-moving imaging is performed by simultaneously irradiating radiation 26 of different energy from the two radiation sources 34. In addition, a mammary gland and calcification have a large absorption rate with respect to radiation of less than 33 keV.

In the second aspect, the following effects are produced.
(2-a) The mammary gland and tumors that were difficult to see due to calcification become easier to see.
(2-b) Since two types of radiations 26 having different energies are irradiated with the same phase, an image (moving image) without deviation can be obtained.
(2-c) Since it is not necessary to acquire an image that does not use a contrast agent, the exposure dose to the subject 24 can be reduced.

Of course, the radiographic imaging system according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention.

Claims

A radiation irradiation system (28) having a radiation source (34), and a radiation image output system (29) for converting the radiation (26) from the radiation source (34) transmitted through the subject (24) into a radiation image and outputting the radiation image. A radiographic imaging device (12) comprising:
A system controller (14) that controls the radiographic imaging apparatus (12) to execute radiographic imaging at a set imaging timing;
The radiation image output system (29) has different sensitivity characteristics, and includes a first imaging unit (54A) and a second imaging unit (54B) that convert the radiation (26) into a radiation image.
The system control unit (14) includes a synchronization unit (124) that synchronizes a plurality of consecutive imaging timings of the first imaging unit (54A) and the second imaging unit (54B). Shooting system.
In the radiographic imaging system of Claim 1,
The system control unit (14) performs radiographic imaging control by switching between still image imaging and moving image imaging in response to a request.
In the radiographic imaging system according to claim 1 or 2,
The system control unit (14) includes a plurality of radiations obtained by the first imaging unit (54A) and the second imaging unit (54B) at the plurality of consecutive imaging timings by the synchronization unit (124). A radiographic imaging system comprising an energy subtraction moving image creating unit (134) that performs subtraction image processing based on an image to create a moving energy subtraction image.
The radiographic imaging system according to any one of claims 1 to 3,
The synchronization unit (124) synchronizes the imaging timing, and a charge accumulation period (Ta1) in the first imaging unit (54A) and a charge accumulation period (Ta2) in the second imaging unit (54B). A radiographic imaging system characterized by overlapping at least a part of the period.
In the radiographic imaging system of Claim 4,
The synchronization unit (124) synchronizes the imaging timing to start the charge accumulation period (Ta1) in the first imaging unit (54A) and the charge accumulation period (Ta2) in the second imaging unit (54B). The radiographic image capturing system is synchronized with the start of
In the radiographic imaging system of Claim 4,
The synchronization unit (124) synchronizes the imaging timing to end the charge accumulation period (Ta1) in the first imaging unit (54A) and the charge accumulation period (Ta2) in the second imaging unit (54B). ) Is synchronized with the end of the radiographic imaging system.
In the radiographic imaging system of Claim 4,
The synchronization unit (124) synchronizes the imaging timing to start the charge accumulation period (Ta1) in the first imaging unit (54A) and the charge accumulation period (Ta2) in the second imaging unit (54B). ) And the end of the charge accumulation period (Ta1) in the first imaging unit (54A) and the end of the charge accumulation period (Ta2) in the second imaging unit (54B). A radiographic imaging system characterized in that
The radiographic imaging system according to any one of claims 1 to 7,
The first imaging unit (54A) has sensitivity to at least a low energy component of the radiation (26),
The radiographic image capturing system, wherein the second imaging unit (54B) has sensitivity to at least a high energy component of the radiation (26).
The radiographic imaging system according to claim 8, wherein
A radiographic imaging system, wherein a maximum frame rate of the imaging timing according to the first imaging unit (54A) is larger than a frame rate of the imaging timing according to the second imaging unit (54B).
The radiographic imaging system according to claim 8 or 9,
The radiographic imaging system characterized in that the spatial resolution of the second imaging unit (54B) is higher than that of the first imaging unit (54A).
The radiographic imaging system according to claim 10, wherein
When the number of pixels of the first imaging unit (54A) is n,
Radiographic imaging system, wherein the number of pixels the second image pickup unit (54B) is n 2.
The radiographic imaging system according to any one of claims 8 to 11,
The radiographic imaging system, wherein an area of a sensitive portion of the second imaging unit (54B) is larger than an area of a sensitive portion of the first imaging unit (54A).
The radiographic imaging system according to any one of claims 8 to 12,
At least the second imaging unit (54B) performs conversion to a radiographic image by thinning or binning according to the setting of the system control unit (14).
The radiographic imaging system according to claim 13, wherein
The system control unit (14) sets at least thinning out or binning of the second imaging unit (54B) in accordance with the synchronized imaging timing by the synchronization unit (124). .
The radiographic imaging system according to any one of claims 1 to 14,
A radiographic imaging system comprising a light shielding layer between the first imaging unit (54A) and the second imaging unit (54B).
The radiographic imaging system according to any one of claims 1 to 15,
A radiographic imaging system comprising a filter having a characteristic of absorbing a specific wavelength between the first imaging unit (54A) and the second imaging unit (54B).
The radiographic image capturing system according to any one of claims 1 to 16,
The radiographic imaging system, wherein the first imaging unit (54A) is installed on an incident side of the radiation (26).
The radiographic image capturing system according to any one of claims 1 to 16,
The radiographic image capturing system, wherein the second imaging unit (54B) is installed on an incident side of the radiation (26).