Radiography system, radiography method, and radiography program

Abstract

To provide a radiography system, a radiography method, and a radiography program that can improve an imaging efficiency in a radiography system capable of executing fluoroscopy and general imaging in a switchable manner.SOLUTION: In a case where a condition that a radiation irradiation area on a detection surface of a radiation detector is equal to or less than a maximum area capable of detecting the radiation in the radiation detector is satisfied, a radiography system sets an imaging mode to a fluoroscopy mode. In a case where the imaging mode is the fluoroscopy mode, the radiography system causes the radiation detector to start processing of continuously acquiring images at a predetermined frame rate irrespectively of whether or not an instruction to start radiation irradiation is received.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a radiographic system, a radiographic method, and a radiographic program.

Background Art

[0002] Patent Document 1 discloses a technique for measuring the distance between an X-ray source and an X-ray detection surface in an X-ray fluoroscopic imaging apparatus.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the medical field, for example, radiographic fluoroscopy is performed for the purpose of examinations such as a barium swallow examination and a cystogram, or for assisting in treatments such as plastic and reconstructive surgery. Also, even when the purpose is to assist in an examination or treatment, general imaging may be performed in addition to fluoroscopic imaging, and in some cases, one radiographic image may be left for recording. In this case, it is preferable if one system can switch between radiographic fluoroscopy and general imaging to improve imaging efficiency. The technique described in Patent Document 1 does not consider switching between fluoroscopic imaging and general imaging. Note that fluoroscopic imaging means continuously capturing a plurality of radiographic images at a predetermined frame rate (i.e., moving image capture). Also, general imaging means recording one radiographic image in response to a shooting instruction by a user such as a radiographer (i.e., still image capture).

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a radiation imaging system, a radiation imaging method, and a radiation imaging program that can improve imaging efficiency in a radiation imaging system capable of switching between fluoroscopic imaging and general imaging of radiation.

Means for Solving the Problems

[0006] A radiation imaging system according to a first aspect includes at least one processor and is capable of switching between fluoroscopic imaging in which a plurality of radiation images are continuously captured at a predetermined frame rate and general imaging in which one radiation image is recorded. The processor sets the imaging mode to the fluoroscopic imaging mode when the irradiation area of the radiation on the detection surface of the radiation detector satisfies the condition that it is less than or equal to the maximum area capable of detecting the radiation in the radiation detector. When the imaging mode is the fluoroscopic imaging mode, the processor causes the radiation detector to start a process of continuously acquiring images at a predetermined frame rate regardless of whether an instruction to start irradiation of the radiation is received.

[0007] A radiation imaging system according to a second aspect is the radiation imaging system according to the first aspect, and when the processor satisfies the condition that the irradiation area is less than or equal to the maximum area, the processor notifies that the condition has been satisfied.

[0008] A radiation imaging system according to a third aspect is the radiation imaging system according to the first aspect or the second aspect, and when the processor does not satisfy the condition that the irradiation area is less than or equal to the maximum area, the processor sets the imaging mode to the general imaging mode.

[0009] A radiation imaging system according to a fourth aspect is the radiation imaging system according to any one of the first aspect to the third aspect, and the above condition is a condition that the distance from the radiation source to the detection surface is less than or equal to a set value.

[0010] The radiographic system according to the fifth aspect is the radiographic system according to any one of the first to fourth aspects, and includes a plurality of processors. A first processor that performs image processing on a radiographic image obtained when the imaging mode is the general imaging mode, and a second processor that performs image processing on a radiographic image obtained when the imaging mode is the fluoroscopic imaging mode are different processors.

[0011] The radiographic system according to the sixth aspect is the radiographic system according to the fifth aspect, and the second processor includes a logic circuit in which the logic of the image processing performed on the radiographic image is pre-programmed.

[0012] The radiographic system according to the seventh aspect is the radiographic system according to any one of the first to sixth aspects. When the imaging mode is the fluoroscopic imaging mode and an instruction to capture a still image is received, the processor generates a single radiographic still image using one or more radiographic images obtained by fluoroscopic imaging.

[0013] The radiographic system according to the eighth aspect is the radiographic system according to the fourth aspect, and the processor receives a designation of a set value.

[0014] The radiographic method according to the ninth aspect is a processor of a radiographic system that includes at least one processor and is capable of switching between fluoroscopic imaging in which a plurality of radiographic images are continuously captured at a predetermined frame rate and general imaging in which one radiographic image is recorded. When the condition that the irradiation area of the radiation on the detection surface of the radiation detector is less than or equal to the maximum area capable of detecting the radiation in the radiation detector is satisfied, the imaging mode is set to the fluoroscopic imaging mode. When the imaging mode is the fluoroscopic imaging mode, a process of causing the radiation detector to continuously acquire images at a predetermined frame rate is executed regardless of whether an instruction to start irradiation of the radiation is received.

[0015] The radiographic program according to the tenth aspect causes a processor of a radiographic system, which includes at least one processor and is capable of switching between fluoroscopic imaging in which a plurality of radiographic images are continuously captured at a predetermined frame rate and general imaging in which one radiographic image is recorded, to execute a process of starting, for a radiation detector, a process of continuously acquiring images at the predetermined frame rate regardless of whether an instruction to start irradiation of radiation has been received, when a condition that an irradiation area of radiation on a detection surface of the radiation detector is equal to or less than a maximum area capable of detecting radiation in the radiation detector is satisfied, and setting the imaging mode to a fluoroscopic imaging mode.

Advantages of the Invention

[0016] According to the present disclosure, in a radiographic system capable of switching between fluoroscopic imaging and general imaging of radiation, the imaging efficiency can be improved.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0018] Hereinafter, with reference to the drawings, exemplary embodiments for implementing the technology of the present disclosure will be described in detail.

[0019] First, with reference to FIG. 1, the configuration of the radiation imaging system 2 will be described. As shown in FIG. 1, the radiation imaging system 2 is a system that irradiates a patient P, which is an example of a subject, with radiation R such as X-rays or γ-rays to capture a radiation image of the patient P, and is operated by an operator such as a radiologic technologist. The radiation imaging system 2 can switch between fluoroscopic imaging that continuously captures a plurality of radiation images at a predetermined frame rate and general imaging that records one radiation image and execute them. The radiation imaging system 2 includes a radiation source 10, a radiation detector 11, a voltage generator 12, a control device 13, a console 14, an upright imaging table 15S, a supine imaging table 15L, an image processing device 16, and a display 17. The radiation source 10, the radiation detector 11, the voltage generator 12, the control device 13, the upright imaging table 15S, the supine imaging table 15L, and the display 17 are installed, for example, in a radiation imaging room of a medical facility. On the other hand, the console 14 and the image processing device 16 are installed, for example, in a control room adjacent to the radiation imaging room. One radiation source 10 and one radiation detector 11 are prepared respectively, and they are shared by the upright imaging table 15S and the supine imaging table 15L.

[0020] The radiation source 10 includes an X-ray tube 20 that emits radiation R, and an irradiation field limiter (also referred to as a collimator) 21 that limits the irradiation field of the radiation R. The X-ray tube 20 is provided with, for example, a filament, a target, and a grid electrode. A voltage is applied from a voltage generator 12 between the filament as the cathode and the target as the anode. The voltage applied between this filament and the target is called the tube voltage. The filament emits thermoelectrons corresponding to the applied tube voltage toward the target. The target emits radiation R by the collision of the thermoelectrons emitted from the filament. The grid electrode is disposed between the filament and the target. The grid electrode changes the flow rate of the thermoelectrons traveling from the filament toward the target according to the voltage applied from the voltage generator 12. The flow rate of the thermoelectrons traveling from the filament toward the target is called the tube current.

[0021] The irradiation field limiter 21 is formed with an incident aperture through which the radiation R from the X-ray tube 20 enters, and an exit aperture through which the radiation R exits. Near the exit aperture, four shielding plates are provided. The shielding plates are formed of a material that shields the radiation R, such as lead. The shielding plates are arranged on each side of a square, in other words, are assembled in a checkered pattern, and form a square irradiation aperture through which the radiation R passes. The irradiation field limiter 21 changes the size of the irradiation aperture by changing the positions of the respective shielding plates, thereby changing the irradiation field of the radiation R.

[0022] The radiation source 10 is suspended from the ceiling of the radiography room by a support column 22. The support column 22 is attached to a rail looped around the ceiling via wheels. The support column 22, and thus the radiation source 10, can be moved horizontally within the radiography room by the rail and the wheels. Further, the support column 22 is telescopable in the height direction, whereby the radiation source 10 can be moved in the height direction. Furthermore, the radiation source 10 is rotatable with respect to the support column 22 about an axis orthogonal to the plane of the paper as the rotation axis.

[0023] Furthermore, the radiation source 10 includes a position sensor that detects the position of the radiation source 10. For example, the position sensor is provided with a variable resistor, and detects the position of the radiation source 10 based on the resistance value of the variable resistor that changes according to the position of the radiation source 10. The position of the radiation source 10 is represented, for example, in a rectangular coordinate system composed of three axes of an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The position of the radiation source 10 detected by the position sensor is transmitted to the control device 13.

[0024] The radiation detector 11 is portable, detects the radiation R that has passed through the patient P, and outputs a radiation image of the patient P. The radiation detector 11 transmits the radiation image to the image processing device 16. The radiation detector 11 is housed and used in the standing imaging table 15S or the lying imaging table 15L. In addition, the radiation detector 11 can be used in a state where it is removed from the standing imaging table 15S or the lying imaging table 15L in the radiation imaging room and held by the patient P, or in a state where it is placed under the patient P lying on the bed in the hospital room. In FIG. 1, an example of taking a radiation image of the chest of the patient P positioned in front of the standing imaging table 15S is illustrated.

[0025] The voltage generator 12 generates a tube voltage to be applied to the X-ray tube 20. The voltage generator 12 and the X-ray tube 20 are connected by a voltage cable. Through this voltage cable, the tube voltage generated in the voltage generator 12 is supplied to the X-ray tube 20.

[0026] The control device 13 controls the operation of the radiation source 10 via the voltage generator 12 according to the irradiation conditions of the radiation R. The irradiation conditions include the tube voltage, tube current, and irradiation time of the radiation R applied to the X-ray tube 20. Note that instead of the tube current and irradiation time, the product of the tube current and irradiation time, so-called mAs value, may be used as the irradiation condition. In fluoroscopic imaging, the control device 13 determines the irradiation conditions in the next frame based on the dose of the radiation R that has reached the radiation detector 11 derived from the radiation image of the previous frame. Thereby, the control device 13 performs dose control of the radiation R in each frame during the irradiation of the radiation R in fluoroscopic imaging.

[0027] An irradiation start instruction is input by an operator to the control device 13 through an irradiation switch (not shown). The irradiation switch is installed in at least one of the control room and the imaging room. The irradiation switch may be a switch operated by hand or a switch operated by foot. When the start instruction is input, the control device 13 operates the voltage generator 12 according to the irradiation conditions and causes the radiation tube 20 to emit radiation R.

[0028] Further, the control device 13 derives the distance from the radiation source 10 to the detection surface of the radiation detector 11 housed in the standing position holder 27S or the lying position holder 27L (hereinafter referred to as "SID (Source to Image receptor Distance)"). As described above, the control device 13 acquires the position of the radiation source 10 transmitted from the position sensor. Also, the positions of the standing position holder 27S and the lying position holder 27L are known. Therefore, the control device 13 can derive the SID when the radiation detector 11 is housed in the standing position holder 27S based on the position of the radiation source 10 and the position of the standing position holder 27S. Further, the control device 13 can derive the SID when the radiation detector 11 is housed in the lying position holder 27L based on the position of the radiation source 10 and the position of the lying position holder 27L. Hereinafter, it is assumed that the SID is known by the control device 13 deriving the SID each time the radiation source 10 is moved.

[0029] The console 14 is, for example, a personal computer. An imaging order 66 described later is registered in the console 14 in advance.

[0030] The standing position imaging table 15S includes a stand 25, a connection part 26, a standing position holder 27S, etc. The stand 25 is composed of a pedestal 28 installed on the floor surface of the imaging room and a column 29 extending in the height direction from the pedestal 28. The connection part 26 connects the standing position holder 27S to the stand 25. The connection part 26, and thus the standing position holder 27S, is movable in the height direction with respect to the column 29, enabling height adjustment according to the height of the patient P or the imaging site.

[0031] The standing position holder 27S is box-shaped and houses the radiation detector 11 inside. Most of the standing position holder 27S is formed of a conductive material having electromagnetic wave shielding properties such as aluminum and stainless steel. Also, the front surface of the standing position holder 27S facing the radiation source 10 is formed of a material that transmits radiation R such as carbon.

[0032] The lying position imaging table 15L has a pedestal 30, a connecting portion 31, a top plate 32, a lying position holder 27L, etc., which are installed on the floor surface of the imaging room. The connecting portion 31 connects the top plate 32 to the pedestal 30. The pedestal 30 is of a lift type, whereby the top plate 32 and the lying position holder 27L can be adjusted in height. The top plate 32 is a rectangular plate having a length and width that allow the patient P to lie supine, and is formed of a material that transmits radiation R such as carbon.

[0033] The lying position holder 27L is disposed in the space between the pedestal 30 and the top plate 32 formed by the connecting portion 31. The lying position holder 27L is box-shaped with its upper part covered by the top plate 32, and houses the radiation detector 11 inside. The lying position holder 27L is formed of a conductive material having electromagnetic wave shielding properties such as aluminum and stainless steel. The lying position holder 27L is slidable in a direction along the long side direction of the top plate 32 by a slide mechanism.

[0034] The image processing apparatus 16 includes a first image processing apparatus 16A and a second image processing apparatus 16B. The first image processing apparatus 16A is a general-purpose computer such as a personal computer, and performs image processing on the radiation image obtained by general imaging. The second image processing apparatus 16B is a computer dedicated to fluoroscopic imaging, and performs image processing on the radiation image obtained by fluoroscopic imaging.

[0035] The display 17 is a liquid crystal display or an EL (Electro Luminescence) display. The display 17 is installed on a display cart with casters and is movable within the radiation imaging room. The display 17 is connected to the image processing apparatus 16.

[0036] As shown in FIG. 2, the radiation detector 11 includes a housing 40 and a detection panel 41. The housing 40 has a substantially rectangular parallelepiped shape that is flat with a rectangular planar shape, and houses the detection panel 41 therein. Most of the front surface of the housing 40 is formed of a material that transmits radiation R such as carbon. The radiation detector 11 is set on the standing holder 27S or the lying holder 27L in a posture where the front surface of the housing 40 faces the radiation source 10.

[0037] The detection panel 41 has a configuration in which a plurality of pixels that generate signal charges in response to radiation R or visible light converted from radiation R by a scintillator are arranged. In addition to the detection panel 41, the housing 40 incorporates a control device 18 described later. The housing 40 also incorporates a communication unit and a battery or the like that supplies power to each part. Note that the radiation detector 11 may be a so-called CR (Computed Radiography) cassette in which an imaging plate is incorporated instead of the detection panel 41.

[0038] The surface of the housing 40 irradiated with the radiation R corresponds to the detection surface of the radiation detector 11. In the present embodiment, the area of the detection surface composed of all the pixels in the detection panel 41 is the maximum area capable of detecting the radiation R in the radiation detector 11.

[0039] Next, with reference to FIG. 3, the hardware configurations of the control device 13, the console 14, the first image processing device 16A, the second image processing device 16B, and the control device 18 will be described. As shown in FIG. 3, the control device 13 includes a CPU (Central Processing Unit) 50, a memory 51 as a temporary storage area, and a non-volatile storage unit 52. The CPU 50 is an example of a processor.

[0040] The storage unit 52 is implemented by a HDD (Hard Disk Drive), SSD (Solid State Drive), flash memory, or the like. A control program 53 is stored in the storage unit 52 as a storage medium. The CPU 50 reads the control program 53 from the storage unit 52, expands it in the memory 51, and executes the expanded control program 53.

[0041] The console 14 includes a CPU 60, a memory 61 as a temporary storage area, a non-volatile storage unit 62, an input device 64 such as a keyboard and a mouse, and a display 65 such as a liquid crystal display or an EL display. The CPU 60 is an example of a processor.

[0042] The storage unit 62 is implemented by a HDD, SSD, or flash memory, or the like. An information processing program 63 is stored in the storage unit 62 as a storage medium. The CPU 60 reads the information processing program 63 from the storage unit 62, expands it in the memory 61, and executes the expanded information processing program 63.

[0043] In addition, a pre-registered imaging order 66 is stored in the storage unit 62. The imaging order 66 includes an irradiation condition of radiation R as an example of imaging conditions for a radiation image in general imaging and an irradiation condition of radiation R as an example of imaging conditions for a radiation image in fluoroscopic imaging. The imaging order 66 also includes patient information such as the age of the patient P, information regarding the build of the patient P, and the imaging site.

[0044] The first image processing device 16A includes a CPU 70, a memory 71 as a temporary storage area, and a non-volatile storage unit 72. The CPU 70 is an example of a processor. The storage unit 72 is implemented by a HDD, SSD, or flash memory, or the like. An image processing program 73 is stored in the storage unit 72 as a storage medium. The CPU 70 reads the image processing program 73 from the storage unit 72, expands it in the memory 71, and executes the expanded image processing program 73.

[0045] The second image processing device 16B includes an FPGA (Field Programmable Gate Array) 80, a memory 81 as a temporary storage area, and a non-volatile storage unit 82. The FPGA 80 is an example of a processor. The storage unit 82 is implemented by an HDD, an SSD, a flash memory, or the like. The FPGA 80 includes a logic circuit in which the logic of image processing performed on a radiation image is pre-programmed.

[0046] The control device 18 includes a CPU 90, a memory 91 as a temporary storage area, a non-volatile storage unit 92, and an image memory 94. The CPU 90 is an example of a processor. The storage unit 92 is implemented by an HDD, an SSD, a flash memory, or the like. A control program 93 is stored in the storage unit 92 as a storage medium. The CPU 90 reads the control program 93 from the storage unit 92 and expands it in the memory 91, and then executes the expanded control program 93. The image memory 94 has a storage capacity capable of storing a predetermined number of radiation images.

[0047] Next, with reference to FIG. 4, the functional configuration of the console 14 will be described. As shown in FIG. 4, the console 14 includes an acquisition unit 100, a transmission unit 102, a reception unit 104, and a display control unit 106. When the CPU 60 executes the information processing program 63, it functions as the acquisition unit 100, the transmission unit 102, the reception unit 104, and the display control unit 106.

[0048] The acquisition unit 100 acquires the imaging order 66 from the storage unit 62. The transmission unit 102 transmits the irradiation conditions in general imaging and the irradiation conditions in fluoroscopic imaging according to the imaging order 66 acquired by the acquisition unit 100 to the control device 13.

[0049] The receiving unit 104 receives the radiation image obtained by general imaging transmitted from the first image processing device 16A. Further, the receiving unit 104 receives the radiation image obtained by fluoroscopic imaging transmitted from the second image processing device 16B. Hereinafter, when distinguishing between the radiation image obtained by general imaging and the radiation image obtained by fluoroscopic imaging, the radiation image obtained by general imaging is referred to as the "first radiation image", and the radiation image obtained by fluoroscopic imaging is referred to as the "second radiation image".

[0050] The display control unit 106 performs control to display the first radiation image received by the receiving unit 104 on the display 65. Further, the display control unit 106 performs control to display a plurality of second radiation images continuously received by the receiving unit 104 on the display 65 according to the frame rate.

[0051] Next, with reference to FIG. 5, the functional configuration of the control device 13 will be described. As shown in FIG. 5, the control device 13 includes a determination unit 110, a setting unit 112, a notification unit 114, a receiving unit 116, a reception unit 118, and an irradiation control unit 120. When the CPU 50 executes the control program 53, it functions as the determination unit 110, the setting unit 112, the notification unit 114, the receiving unit 116, the reception unit 118, and the irradiation control unit 120.

[0052] The determination unit 110 determines whether or not the condition that the irradiation area of the radiation R on the detection surface of the radiation detector 11 is equal to or less than the maximum area capable of detecting the radiation R in the radiation detector 11 is satisfied. The irradiation area of the radiation R is determined according to the SID and the area of the irradiation aperture of the irradiation field limiter 21. In the present embodiment, the determination unit 110 determines whether or not the above condition is satisfied by determining whether the SID is equal to or less than the first set value and the area of the irradiation aperture is equal to or less than the second set value. The first set value and the second set value are determined according to the standard according to the size of the detection surface of the radiation detector 11 used for fluoroscopic imaging (for example, 19 inches, etc.). For example, the determination unit 110 performs the above determination when the position of the radiation source 10 is changed or when the positions of the four shielding plates of the irradiation field limiter 21 are changed.

[0053] Note that when the positions of the four shielding plates of the irradiation field limiter 21 are fixed, that is, when the area of the irradiation aperture is a fixed value, the determination unit 110 may use only the first set value among the first set value and the second set value. In this case, the determination unit 110 determines whether the above conditions are satisfied by determining whether the SID is less than or equal to the first set value. Further, the determination unit 110 may perform the above determination at a predetermined time interval.

[0054] Also, the first set value and the second set value may be, for example, specifiable by the operator. In this case, the CPU 50 receives the specification of the first set value and the second set value by the operator.

[0055] When it is determined by the determination unit 110 that the conditions are satisfied, the setting unit 112 sets the shooting mode to the fluoroscopic shooting mode. In this case, the setting unit 112 transmits an instruction to set the shooting mode to the fluoroscopic shooting mode to the control device 18, and the CPU 90 of the control device 18 sets the shooting mode to the fluoroscopic shooting mode.

[0056] Also, when it is determined by the determination unit 110 that the conditions are not satisfied, the setting unit 112 sets the shooting mode to the general shooting mode. In this case, the setting unit 112 transmits an instruction to set the shooting mode to the general shooting mode to the control device 18, and the CPU 90 of the control device 18 sets the shooting mode to the general shooting mode. In the present embodiment, the general shooting mode is set as the initial shooting mode at the time of starting the system, that is, the default shooting mode.

[0057] The process of setting the shooting mode to either the general shooting mode or the fluoroscopic shooting mode is performed, for example, by setting the value representing the shooting mode stored in the storage unit of each device to a value representing either the general shooting mode or the fluoroscopic shooting mode. Note that the value representing the shooting mode may be stored in a shared storage unit accessible from each device. Also, the shooting mode may be set by a physical switch.

[0058] When the determination unit 110 determines that the conditions are satisfied, the notification unit 114 notifies that the conditions are satisfied. For example, the notification unit 114 notifies that the conditions are satisfied by blinking a display provided on the radiation source 10. Note that the notification unit 114 may notify that the conditions are satisfied by voice output via a speaker. Further, the notification unit 114 may notify that the conditions are satisfied by fixing the position of the radiation source 10 so that it cannot be changed, such as locking the moving mechanism of the radiation source 10.

[0059] Further, the notification unit 114 may output instruction information indicating an instruction for notification to the first image processing device 16A. In this case, the CPU 70 of the first image processing device 16A may notify that the conditions are satisfied by performing control to display a message indicating that the conditions are satisfied on the display 17. Further, the notification unit 114 may output instruction information indicating an instruction for notification to the console 14. In this case, the CPU 60 of the console 14 may notify that the conditions are satisfied by performing control to display a message indicating that the conditions are satisfied on the display 65.

[0060] The reception unit 116 receives the irradiation conditions in general photography and the irradiation conditions in fluoroscopic photography transmitted from the console 14. The reception unit 118 receives an instruction to start radiation imaging via an irradiation switch.

[0061] The irradiation control unit 120 controls the operation of the radiation source 10. Specifically, when the reception unit 118 receives an instruction to start radiation imaging and the imaging mode is the general imaging mode, the irradiation control unit 120 operates the voltage generator 12 according to the irradiation conditions in general photography received by the reception unit 116, and causes the radiation tube 20 to emit radiation R. Further, when the reception unit 118 receives an instruction to start radiation imaging and the imaging mode is the fluoroscopic imaging mode, the irradiation control unit 120 operates the voltage generator 12 according to the irradiation conditions in fluoroscopic photography received by the reception unit 116, and causes the radiation tube 20 to emit radiation R.

[0062] In addition, the irradiation control unit 120 outputs an irradiation start signal for notifying the start of irradiation of the radiation R and an irradiation end signal for notifying the end of irradiation of the radiation R to the control device 18.

[0063] Next, with reference to FIG. 6, the functional configuration of the control device 18 will be described. As shown in FIG. 6, the control device 18 includes a receiving unit 130, a detector control unit 132, and a transmitting unit 134. When the CPU 90 executes the control program 93, it functions as the receiving unit 130, the detector control unit 132, and the transmitting unit 134.

[0064] The receiving unit 130 receives the irradiation start signal and the irradiation end signal transmitted from the control device 13. The detector control unit 132 controls the operation of the radiation detector 11. Specifically, when the imaging mode is the fluoroscopic imaging mode, the detector control unit 132 causes the radiation detector 11 to start a process of continuously acquiring images at a predetermined frame rate regardless of whether an instruction to start irradiation of the radiation R has been received.

[0065] That is, when the imaging mode of the radiation detector 11 is set to the fluoroscopic imaging mode, the detector control unit 132 causes the radiation detector 11 to start a process of continuously acquiring images by repeatedly performing a charge accumulation operation and a charge readout operation on the detection panel 41 according to the frame rate. Therefore, when the imaging mode is the fluoroscopic imaging mode, image acquisition is started even before the start of irradiation of the radiation R. The acquired image can be used as an offset correction image. In addition, since image acquisition is started even before the start of irradiation of the radiation R, saturation of the temperature rise of the detection panel 41 can be promoted.

[0066] In addition, when the shooting mode is the general shooting mode, upon receiving the irradiation start signal by the receiving unit 130, the detector control unit 132 causes the detection panel 41 to perform a charge accumulation operation. Further, when the shooting mode is the general shooting mode, upon receiving the irradiation end signal by the receiving unit 130, the detector control unit 132 causes the detection panel 41 to perform a charge readout operation. Thereby, in the general shooting mode, one radiation image is acquired.

[0067] When the shooting mode is the general shooting mode, the transmitting unit 134 transmits the first radiation image obtained under the control of the detector control unit 132 to the first image processing apparatus 16A. Further, when the shooting mode is the fluoroscopic shooting mode, the transmitting unit 134 sequentially transmits the second radiation images obtained at a predetermined frame rate under the control of the detector control unit 132 to the second image processing apparatus 16B.

[0068] Next, with reference to FIG. 7, the functional configuration of the first image processing apparatus 16A will be described. As shown in FIG. 7, the first image processing apparatus 16A includes a receiving unit 140, an image processing unit 142, and a transmitting unit 144. When the CPU 70 executes the image processing program 73, it functions as the receiving unit 140, the image processing unit 142, and the transmitting unit 144.

[0069] The receiving unit 140 receives the first radiation image transmitted from the radiation detector 11. The image processing unit 142 performs various image processes such as an offset correction process, a sensitivity correction process, and a defective pixel correction process on the first radiation image received by the receiving unit 140.

[0070] The offset correction process is a process of subtracting, on a pixel-by-pixel basis, the offset correction image acquired in a state where no radiation R is irradiated from the radiation image. The sensitivity correction process is a process of correcting variations in sensitivity of each pixel of the detection panel 41 of the radiation detector 11 and variations in output characteristics of a circuit for reading out signal charges, etc., based on the sensitivity correction data. The defective pixel correction process is a process of linearly interpolating the pixel value of a defective pixel with the pixel values of surrounding normal pixels based on information on defective pixels with abnormal pixel values generated at the time of shipment or during regular inspections.

[0071] The transmission unit 144 transmits the first radiation image that has undergone the image processing by the image processing unit 142 to the console 14.

[0072] Next, with reference to FIG. 8, the functional configuration of the second image processing apparatus 16B will be described. As shown in FIG. 8, the second image processing apparatus 16B includes a reception unit 150, an image processing unit 152, and a transmission unit 154. The FPGA 80 functions as the reception unit 150, the image processing unit 152, and the transmission unit 154 by executing a pre-programmed logic.

[0073] The reception unit 150 receives the second radiation image transmitted from the radiation detector 11. The image processing unit 152 performs various image processes such as offset correction processing, sensitivity correction processing, and defective pixel correction processing on the second radiation image received by the reception unit 150. The transmission unit 154 transmits the second radiation image that has undergone the image processing by the image processing unit 152 to the console 14.

[0074] As described above, the CPU 70, which is the first processor that performs image processing on the first radiation image obtained when the imaging mode is the general imaging mode, and the FPGA 80, which is the second processor that performs image processing on the second radiation image obtained when the imaging mode is the fluoroscopic imaging mode, are different processors. For the second radiation image, since the image processing is performed at high speed by the FPGA 80, which is a dedicated processor for fluoroscopic imaging with logic pre-programmed, a high frame rate can be realized.

[0075] Next, with reference to FIGS. 9 and 10, the operation of the radiation imaging system 2 will be described. FIGS. 9 and 10 are sequence diagrams showing an example of the radiation image imaging process executed by the radiation imaging system 2. Here, as an example, the processing flow when general imaging is performed after fluoroscopic imaging will be described.

[0076] When the imaging order 66 is registered, in step S10, the acquisition unit 100 acquires the imaging order 66 from the storage unit 62. Then, the transmission unit 102 transmits to the control device 13 the irradiation conditions in general imaging and the irradiation conditions in fluoroscopic imaging corresponding to the imaging order 66 acquired by the acquisition unit 100. The reception unit 116 receives the irradiation conditions in general imaging and the irradiation conditions in fluoroscopic imaging transmitted from the console 14 in step S10.

[0077] The operator positions the patient P in front of the standing imaging table 15S or supine on the top plate 32 of the lying imaging table 15L according to the imaging order 66. Then, the operator adjusts the position of the radiation source 10. In response to the adjustment of the position of the radiation source 10 by the operator, the determination unit 110 determines whether or not the condition that the irradiation area of the radiation R on the detection surface of the radiation detector 11 is equal to or less than the maximum area capable of detecting the radiation R in the radiation detector 11 is satisfied. When it is determined by the determination unit 110 that the condition is satisfied, in step S12, the setting unit 112 sets the imaging mode to the fluoroscopic imaging mode as described above. Next, in step S14, the notification unit 114 notifies that the condition has been satisfied as described above.

[0078] When the imaging mode is set to the fluoroscopic imaging mode, in step S16, the detector control unit 132 causes the radiation detector 11 to start the process of continuously acquiring images at a predetermined frame rate as described above.

[0079] The operator receives the notification in step S14 and inputs an instruction to start radiation imaging via the irradiation switch. The reception unit 118 receives the instruction to start radiation imaging via the irradiation switch. When the start instruction is received by the reception unit 118, in step S18, the irradiation control unit 120 operates the voltage generator 12 according to the irradiation conditions in fluoroscopic imaging received by the reception unit 116, and causes the radiation tube 20 to emit the radiation R. Thereby, the irradiation of the radiation R is started.

[0080] In step S20, the transmission unit 134 sequentially transmits the second radiation image obtained at a predetermined frame rate under the control of the detector control unit 132 to the second image processing device 16B. The reception unit 150 receives the second radiation image transmitted from the radiation detector 11 in step S20.

[0081] In step S22, as described above, the image processing unit 152 performs various image processes on the second radiation image received by the reception unit 150. In step S24, the transmission unit 154 transmits the second radiation image that has undergone the image processing in step S22 to the console 14. The reception unit 104 receives the second radiation image transmitted from the second image processing device 16B in step S24. In step S26, the display control unit 106 controls to display a plurality of second radiation images continuously received by the reception unit 104 on the display 65 according to the frame rate.

[0082] The operator terminates the fluoroscopic imaging by terminating the irradiation of the radiation R. Further, when the fluoroscopic imaging is terminated, the operator adjusts the position of the radiation source 10 according to the general imaging. In response to the adjustment of the position of the radiation source 10 by the operator, the determination unit 110 determines whether or not the condition that the irradiation area of the radiation R on the detection surface of the radiation detector 11 is equal to or less than the maximum area capable of detecting the radiation R in the radiation detector 11 is satisfied. When it is determined by the determination unit 110 that the condition is not satisfied, in step S28, as described above, the setting unit 112 sets the imaging mode to the general imaging mode.

[0083] Next, the operator inputs an instruction to start radiography via the irradiation switch. The reception unit 118 receives the instruction to start radiography via the irradiation switch. When the start instruction is received by the reception unit 118, in step S30, the irradiation control unit 120 operates the voltage generator 12 according to the irradiation conditions in general radiography received by the reception unit 116, and causes the radiation tube 20 to emit radiation R. Thereby, the irradiation of the radiation R is started. Then, the irradiation control unit 120 outputs an irradiation start signal notifying the start of the irradiation of the radiation R to the control device 18. The reception unit 130 receives the irradiation start signal transmitted from the control device 13 in step S30.

[0084] When the reception unit 130 receives the irradiation start signal, in step S32, the detector control unit 132 causes the detection panel 41 to perform a charge accumulation operation. When the irradiation time of the radiation R started in step S30 has elapsed, in step S34, the irradiation control unit 120 ends the irradiation of the radiation R from the radiation tube 20. Then, the irradiation control unit 120 outputs an irradiation end signal notifying the end of the irradiation of the radiation R to the control device 18. The reception unit 130 receives the irradiation end signal transmitted from the control device 13 in step S34.

[0085] When the reception unit 130 receives the irradiation end signal, in step S36, the detector control unit 132 causes the detection panel 41 to perform a charge readout operation. Then, the transmission unit 134 transmits the first radiation image obtained by this readout operation to the first image processing device 16A. The reception unit 140 receives the first radiation image transmitted from the radiation detector 11 in step S36.

[0086] In step S38, as described above, the image processing unit 142 performs various image processes on the first radiation image received by the receiving unit 140. In step S40, the transmitting unit 144 transmits the first radiation image that has undergone the image processing in step S38 to the console 14. The receiving unit 104 receives the first radiation image transmitted from the first image processing apparatus 16A in step S40. In step S42, the display control unit 106 performs control to display the first radiation image received by the receiving unit 104 on the display 65.

[0087] As described above, according to the present embodiment, in a radiation imaging system capable of switching between fluoroscopic imaging and general imaging of radiation, the imaging efficiency can be improved.

[0088] In the above embodiment, in the fluoroscopic imaging mode, the operator may be able to input an instruction to capture a still image. In this case, when the imaging mode is the fluoroscopic imaging mode and an instruction to capture a still image is received, the CPU 60 of the console 14 may generate a single radiation still image using one or more radiation images obtained by fluoroscopic imaging. For example, the CPU 60 may generate one radiation still image by generating an average image of a plurality of radiation images obtained by fluoroscopic imaging. Further, the process of generating this radiation still image may be executed by a processor of a device other than the console 14, such as the FPGA 80 of the second image processing apparatus 16B.

[0089] Also, each functional unit in the above embodiment may be provided in a device different from the device in which the functional unit is provided in the above embodiment. Further, each functional unit in the above embodiment may be realized by one computer.

[0090] Also, in the above embodiment, for example, as the hardware structure of a processing unit that executes various processes such as each functional unit of each device, the following various processors can be used. Among the above various processors, as described above, in addition to the CPU which is a general-purpose processor that executes software (program) and functions as various processing units, there are a programmable logic device (PLD) which is a processor whose circuit configuration can be changed after manufacturing such as an FPGA, and a dedicated electric circuit which is a processor having a circuit configuration dedicated to executing specific processes such as an ASIC (Application Specific Integrated Circuit).

[0091] One processing unit may be composed of one of these various processors, or may be composed of a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, a plurality of processing units may be composed of one processor.

[0092] As an example of configuring a plurality of processing units with one processor, first, as represented by computers such as clients and servers, there is a form in which one processor is configured by a combination of one or more CPUs and software, and this processor functions as a plurality of processing units. Second, as represented by a system on chip (SoC), there is a form in which a processor that realizes the functions of the entire system including a plurality of processing units with one IC (Integrated Circuit) chip is used. Thus, various processing units are configured using one or more of the above various processors as the hardware structure.

[0093] Furthermore, as the hardware structure of these various processors, more specifically, an electric circuit (circuitry) combining circuit elements such as semiconductor elements can be used.

[0094] Also, in the above-described embodiment, although the mode in which various programs are stored (installed) in advance in the storage unit has been described, the present invention is not limited to this. The various programs may be provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), or a USB (Universal Serial Bus) memory. Further, the various programs may be in a form downloaded from an external device via a network.

Explanation of Reference Numerals

[0095] 2 Radiation imaging system 10 Radiation source 11 Radiation detector 12 Voltage generator 13, 18 Control device 14 Console 15L Horizontal imaging table 15S Standing imaging table 16 Image processing device 16A First image processing device 16B Second image processing device 17, 65 Display 20 X-ray tube 21 Irradiation field limiter 22, 29 Support column 25 Stand 26, 31 Connection part 27L Holder for horizontal position 27S Holder for standing position 28, 30 Pedestal 32 Top plate 40 Housing 41 Detection panel 50, 60, 70, 90 CPU 51, 61, 71, 81, 91 Memory 52, 62, 72, 82, 92 Storage unit 53, 93 Control program 63 Information processing program 64 Input device 66 Shooting order 73 Image processing program 80 FPGA 94 Image memory 100 Acquisition unit 102, 134, 144, 154 Transmission unit 104, 116, 130, 140, 150 Reception unit 106 Display control unit 110 Judgment unit 112 Setting unit 114 Notification unit 118 Reception unit 120 Irradiation control unit 132 Detector control unit 142, 152 Image processing unit P Patient R Radiation

Claims

1. A fluoroscopic imaging system including at least one processor and capable of switching between and performing fluoroscopic imaging for continuously capturing a plurality of radiographic images at a predetermined frame rate and general imaging for recording a single radiographic image, wherein the processor sets the imaging mode to the fluoroscopic imaging mode when a condition that an irradiation area of radiation on a detection surface of a radiation detector is equal to or less than a maximum area capable of detecting radiation in the radiation detector is satisfied, and when the imaging mode is the fluoroscopic imaging mode, causes the radiation detector to start a process of continuously acquiring images at the predetermined frame rate regardless of whether an instruction to start irradiation of radiation has been received. A radiographic imaging system.

2. The processor notifies that the condition has been satisfied when the irradiation area satisfies the condition of being equal to or less than the maximum area. The radiographic imaging system according to claim 1.

3. The processor sets the imaging mode to the general imaging mode when the irradiation area does not satisfy the condition of being equal to or less than the maximum area. The radiographic imaging system according to claim 1 or claim 2.

4. The condition is a condition that a distance from a radiation source to the detection surface is equal to or less than a set value. The radiographic imaging system according to claim 1 or claim 2.

5. including a plurality of processors, wherein a first processor that performs image processing on a radiographic image obtained when the imaging mode is the general imaging mode and a second processor that performs image processing on a radiographic image obtained when the imaging mode is the fluoroscopic imaging mode are different processors. The radiographic imaging system according to claim 1 or claim 2.

6. The second processor includes a logic circuit in which logic for image processing to be performed on the radiographic image is pre-programmed. The radiographic imaging system according to claim 5.

7. The processor generates a single radiographic still image using one or more radiographic images obtained by fluoroscopic imaging when the imaging mode is the fluoroscopic imaging mode and an instruction to capture a still image has been received. The radiographic imaging system according to claim 1 or claim 2.

8. The processor receives a designation of the set value. The radiographic imaging system according to claim 4.

9. A processor of a radiation imaging system that includes at least one processor and is capable of switching between fluoroscopic imaging in which a plurality of radiation images are continuously captured at a predetermined frame rate and general imaging in which one radiation image is recorded, sets the imaging mode to the fluoroscopic imaging mode when a condition that the irradiation area of radiation on the detection surface of the radiation detector is equal to or less than the maximum area capable of detecting radiation in the radiation detector is satisfied, and when the imaging mode is the fluoroscopic imaging mode, causes the radiation detector to start a process of continuously acquiring images at the predetermined frame rate regardless of whether an instruction to start irradiation of radiation has been received. A radiation imaging method for executing the process. **Claim 10** A processor of a radiation imaging system that includes at least one processor and is capable of switching between fluoroscopic imaging in which a plurality of radiation images are continuously captured at a predetermined frame rate and general imaging in which one radiation image is recorded, sets the imaging mode to the fluoroscopic imaging mode when a condition that the irradiation area of radiation on the detection surface of the radiation detector is equal to or less than the maximum area capable of detecting radiation in the radiation detector is satisfied, and when the imaging mode is the fluoroscopic imaging mode, causes the radiation detector to start a process of continuously acquiring images at the predetermined frame rate regardless of whether an instruction to start irradiation of radiation has been received. A radiation imaging program for causing the process to be executed.

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