JP2021041239A - Image processing apparatus and method and program for operating the same - Google Patents

Abstract

To provide an image processing apparatus capable of detecting an accurate position of an irradiation field and applying appropriate image processing on a radiographic image, and to provide a method and program for operating the image processing apparatus.SOLUTION: A camera image acquisition unit 80 acquires a camera image output from a camera 23 fitted to an X-ray source 13 and imaging at least a subject. A detection unit 82 detects a portion corresponding to an irradiation field and a portion corresponding to a non-irradiation field out of a radiation image based on X-rays applied from the X-ray source 13 and having passed through the subject, on the basis of the camera image. An image processing unit 83 performs image processing for the radiation image on the basis of the portion corresponding to the irradiation field and the portion corresponding to the non-irradiation field.SELECTED DRAWING: Figure 8

Description

The present invention relates to an image processing device, an operation method thereof, and an operation program.

In the medical field, diagnosis based on a radiographic image detected by a radiological image detection device is actively performed. The radiographic image detection device has a sensor panel. The sensor panel is provided with a photographing area. A plurality of pixels are arranged two-dimensionally in the shooting area. Pixels accumulate charges in response to radiation emitted from a radiation source and transmitted through a subject (patient). The radiographic image detection device converts the electric charge accumulated in the pixel into a digital signal and outputs this as a radiographic image.

There are two types of radiation image detection devices: a stationary type that is fixed to an imaging table installed in an imaging room, and a portable type in which a sensor panel or the like is housed in a portable housing. A portable radiographic image detector is called an electronic cassette. Electronic cassettes include a wired type that is powered by a commercial power source via a cable, and a wireless type that is powered by a battery mounted in a housing.

Taking advantage of its mobility, the electronic cassette is taken out of the shooting room for use. For example, it is used for round-trip photography in which a patient who cannot go to the imaging room is visited and photographed. In addition, electronic cassettes are sometimes used outside medical facilities to photograph elderly people undergoing medical treatment at home and suddenly ill people due to accidents, disasters, etc. Shooting without using a shooting table in this way is hereinafter referred to as free shooting.

By the way, the radiation source is provided with an irradiation field limiter (also called a collimator). The irradiation field limiter has an irradiation aperture that sets the irradiation field. Here, the irradiation field is an area where radiation is irradiated. An operator such as a radiologist changes the size of the irradiation opening of the irradiation field limiting device to set the irradiation field according to the imaging order instructed by the imaging requester such as a doctor.

Depending on the content of the shooting order, the entire shooting area of the sensor panel may not be the irradiation field, and the shooting area may be not irradiated with radiation (hereinafter, non-irradiation field). In this case, the part of the radiation image corresponding to the non-irradiated field (hereinafter, the part corresponding to the non-irradiated field) is displayed in white as it is, and is displayed in black with the part corresponding to the irradiated field (hereinafter, the part corresponding to the irradiated field). The contrast is too strong and interferes with observation.

Therefore, conventionally, as described in Patent Document 1, for example, when displaying a radiation image, the position of the irradiation field is detected, and the portion other than the irradiation field corresponding to the detected irradiation field, that is, the non-irradiation field corresponding portion. The radiographic image was subjected to blackening treatment to fill the area with black and trimming treatment to remove the corresponding part of the non-irradiated field.

In Patent Document 1, the position of the irradiation field is detected by image analysis of a radiographic image. For example, a portion of a radiation image in which the pixel value (density) changes rapidly is extracted as a boundary (edge) between an irradiated field and a non-irradiated field, and a rectangular area formed by the extracted boundary is detected as an irradiation field. ing. Alternatively, a dynamic contour extraction algorithm represented by the Snake method is applied to a radiographic image to extract the contour of the irradiation field and detect it as the irradiation field.

Japanese Unexamined Patent Publication No. 2015-100592

However, the irradiation field is set to various shapes, not limited to a rectangle, and the pixel value of the radiation image varies depending on the irradiation conditions of the radiation, and the radiation has characteristics such as scattering and diffraction. For this reason, the outline of the irradiation field in the radiographic image may not be clear. Therefore, the method of detecting the position of the irradiation field by image analysis of the radiation image as in Patent Document 1 does not have very high reliability of the detected position of the irradiation field.

An object of the present invention is to provide an image processing apparatus capable of detecting the accurate position of an irradiation field and performing appropriate image processing on a radiographic image, and an operation method and operation program thereof. ..

The image processing apparatus of the present invention is attached to a radiation source and at least has a camera image acquisition unit that acquires a camera image output from a camera that captures the subject, and is irradiated from the radiation source to transmit the subject based on the camera image. Image processing is performed on the radiation image based on the detection unit that detects the irradiation field corresponding part and the non-irradiation field corresponding part and the irradiation field corresponding part and the non-irradiation field corresponding part in the radiation image based on the radiation. It is equipped with an image processing unit.

The corresponding part of the irradiation field is the part of the radiation corresponding to the irradiation field which is the area where the radiation is irradiated, and the part corresponding to the non-irradiation field is the radiation corresponding to the non-irradiation field which is the area where the radiation other than the irradiation field is not irradiated. It is preferable that it is a part of. It is preferable that the radiation source has an irradiation field display light source that emits irradiation field display light indicating the irradiation field, and the detection unit detects the position of the irradiation field based on the irradiation field display light reflected in the camera image.

The electronic cassette that detects the radiographic image is provided with an imaging area that detects the radiological image.
The first acquisition unit that acquires the reference size LIM0 of the irradiation field in the camera image at the preset reference distance SID0 with the focal position of the radiation tube of the radiation source as the end point, and the focal position and imaging area during radiography. The detection unit includes a second acquisition unit that acquires the distance SID1 from the above, and the detection unit is derived from the reference size LIM0 acquired by the first acquisition unit, the reference distance SID0, and the distance SID1 acquired by the second acquisition unit. It is preferable to calculate the size LIM1 of the irradiation field in the camera image at the time of radiography.

The radiation source is provided with an irradiation field limiting device having an irradiation aperture for setting the irradiation field, and the first acquisition unit acquires the size of the irradiation opening at the time of radiography, and the acquired size of the irradiation opening. It is preferable to acquire the reference size LIM0 corresponding to. The image processing unit is a first image processing unit that performs the first image processing as image processing on the portion corresponding to the irradiation field, and / and a second image processing that performs the second image processing as image processing on the portion corresponding to the non-irradiation field. It is preferable to include a portion.

It is preferable that the first image processing unit performs multi-frequency processing and dynamic range compression processing on the irradiation field corresponding portion as the first image processing. As the second image processing, the second image processing unit may perform a blackening process of filling the non-irradiated field applicable part with black, or a trimming process of removing the non-irradiated field applicable part and leaving only the irradiated area applicable part. preferable. It is preferable to include an association processing unit that associates the information of either the irradiation field applicable portion or the non-irradiation field applicable portion with the radiation image as incidental information of the radiation image.

The method of operating the image processing apparatus of the present invention is a camera image acquisition step of acquiring at least a camera image output from a camera that is attached to a radiation source and captures a subject, and irradiation from the radiation source based on the camera image. An image with respect to the radiation image based on the detection step of detecting the irradiation field corresponding part and the non-irradiation field corresponding part in the radiation image based on the radiation transmitted through the subject, and the irradiation field corresponding part and the non-irradiation field corresponding part. It includes an image processing step for performing processing.

The operation program of the image processing device of the present invention is attached to a radiation source and has a camera image acquisition function for acquiring at least a camera image output from a camera that captures a subject, and is irradiated from the radiation source based on the camera image. Based on the detection function that detects the irradiation field applicable part and the non-irradiation field applicable part in the radiation image based on the radiation transmitted through the subject, and the irradiation field applicable part and the non-irradiation field applicable part, the image is obtained for the radiation image. Let the computer execute the image processing function that performs the processing.

According to the present invention, it is possible to provide an image processing device capable of detecting an accurate position of an irradiation field and performing appropriate image processing on a radiation image, and an operation method and operation program thereof. ..

It is a figure which shows the X-ray imaging system. It is a figure which shows the image file. It is an external perspective view of an electronic cassette. It is a figure which shows the X-ray image. It is a figure which shows the flow of the operation performed by an electronic cassette. It is a figure which shows the camera image. It is a block diagram of the computer which constitutes a console. It is a block diagram of the CPU of the console. It is a block diagram of an image processing part. It is a flowchart which shows the processing procedure of the CPU of a console. It is a flowchart which shows the processing procedure of an image processing part. FIG. 12A shows a state of free shooting when the irradiation field is set obliquely with respect to the shooting area and the arm is the shooting part, and FIG. 12B shows an X-ray image. It is a block diagram of the image processing part of another example. It is a block diagram of the CPU of the console of the 2nd Embodiment. It is a reference figure of the 2nd Embodiment. It is a block diagram of the CPU of the console of 3rd Embodiment.

[First Embodiment]
In FIG. 1, an X-ray imaging system 10 that uses X-rays as radiation includes an X-ray generator 11 and an X-ray imaging device 12. The X-ray generator 11 is composed of an X-ray source 13 corresponding to a radiation source and a radiation source control device 14. The X-ray imaging apparatus 12 includes an electronic cassette 15 and a console 16 corresponding to an image processing apparatus.

In FIG. 1, in an imaging room in which an X-ray imaging system 10 is installed, an electronic cassette 15 is placed on a table 17 facing the X-ray source 13, and an imaging portion of subject H (in this example, a hand) is placed on the electronic cassette 15. ) Is placed to show the state of performing X-ray photography. That is, the X-ray photography shown in FIG. 1 is a free radiography performed without using an imaging table.

The X-ray source 13 includes an X-ray tube 20 that generates X-rays, an irradiation field limiter 21 that limits the irradiation field IF (see FIG. 3 and the like) that is an area irradiated with X-rays, and an irradiation indicating the irradiation field IF. It has a built-in irradiation field display light source 22 that emits field display light LIF (see also FIG. 3 and the like).

The X-ray tube 20 has a filament that emits thermoelectrons and a target that the thermoelectrons emitted from the filament collide with each other to emit X-rays. In the irradiation field limiting device 21, for example, four lead plates that shield X-rays are arranged on each side of the quadrangle, and a quadrangular irradiation opening for transmitting X-rays is formed in the center. In this case, the irradiation field limiting device 21 changes the size of the irradiation opening by moving the position of the lead plate, and sets the irradiation field IF. The irradiation field display light source 22 irradiates the irradiation field display light LIF through the irradiation opening of the irradiation field limiting device 21. Therefore, the irradiation field display light LIF literally has the same shape and size as the irradiation field IF. The irradiation field display light source 22 emits an irradiation field display light LIF of a special color (for example, yellow) so that the operator can see it even in a shooting room where the illumination is turned off.

An optical camera 23 is attached to the X-ray source 13. After the operator positions the X-ray source 13, the electronic cassette 15, and the subject H relative to each other for X-ray photography, the camera 23 moves into the field of view (hereinafter referred to as FOV (Field Of View)). The electronic cassette 15 and the subject H are captured. The camera 23 captures a camera image 63 (see FIG. 6), which is an optical image including the electronic cassette 15 and the subject H. The camera image 63 is, for example, a color image and a still image.

Here, the "camera attached to the radiation source" referred to in the claims is of course not only when it is directly attached to the outer peripheral portion of the X-ray source 13 as shown in FIG. 1, but also as in the irradiation field display light source 22. The case where it is built in the radiation source 13 is also included. Even when the objective lens is arranged on the outer peripheral portion of the X-ray source 13 and the image sensor is built in other than the X-ray source 13 (for example, an arm for suspending the X-ray source 13 from the ceiling), the "radioactive source" referred to in the claim. Included in "Camera mounted on".

The camera 23 has a wireless communication unit and a battery, and operates wirelessly. The camera 23 wirelessly receives the shooting instruction signal from the console 16 and shoots the camera image 63 in response to the shooting instruction signal. The camera 23 wirelessly transmits the captured camera image 63 to the console 16.

The radiation source control device 14 includes a touch panel 25, a voltage generation unit 26, a control unit 27, and an irradiation switch 28. The touch panel 25 is operated when setting the X-ray irradiation condition consisting of the tube voltage applied to the X-ray tube 20, the tube current, and the X-ray irradiation time, and the size of the irradiation opening of the irradiation field limiter 21. To. Here, the tube current is a parameter that determines the flow rate of thermions from the filament of the X-ray tube 20 toward the target.

The voltage generation unit 26 generates a tube voltage to be applied to the X-ray tube 20. The control unit 27 controls the operation of the voltage generation unit 26 to control the tube voltage, the tube current, and the X-ray irradiation time. The control unit 27 has a timer that starts timing when X-rays are generated from the X-ray tube 20, and when the time measured by the timer reaches the irradiation time set by the irradiation conditions, the X-ray tube 20 Stop the operation. Further, the control unit 27 operates the irradiation field limiting device 21 to set the size of the irradiation opening to the size set by the touch panel 25.

The irradiation switch 28 is operated by the operator when starting the irradiation of X-rays. The irradiation switch 28 is a two-stage pressing type. When the irradiation switch 28 is pressed (half-pressed) to the first stage, the control unit 27 starts a preparatory operation before generating X-rays in the X-ray tube 20. When the irradiation switch 28 is pressed (fully pressed) to the second stage, the control unit 27 generates X-rays in the X-ray tube 20. As a result, X-rays are emitted toward the hand, which is the imaging portion of the subject H.

The electronic cassette 15 detects an X-ray image 40 (see FIG. 2) based on X-rays irradiated from the X-ray source 13 and transmitted through the subject H. Like the camera 23, the electronic cassette 15 has a wireless communication unit and a battery, and operates wirelessly. The electronic cassette 15 wirelessly transmits the X-ray image 40 to the console 16.

The console 16 is configured by installing a control program such as an operating system and various application programs based on a computer such as a notebook personal computer. The console 16 has a display 30 and an input device 31 such as a touch pad and a keyboard. The console 16 displays various operation screens provided with operation functions by GUI (Graphical User Interface) on the display 30, and receives input of various operation instructions by the operator from the input device 31 through various operation screens.

Various operation instructions input via the input device 31 include a shooting menu and condition setting instructions including irradiation conditions corresponding thereto. The shooting menu defines, for example, a shooting technique in which a shooting part, a posture, and an orientation are set as one set. In addition to the hands illustrated in FIG. 1, the imaging sites include the head, cervical spine, chest, abdomen, fingers, elbows, arms, knees, and the like. The posture is the posture of the subject H such as standing, lying, and sitting, and the orientation is the orientation of the subject H with respect to the X-ray source 13 such as the front, side, and back. The condition setting instruction is an instruction for setting a shooting menu and irradiation conditions according to a shooting order, and is input by the operator. The imaging order is issued by a imaging requester such as a doctor in a clinical department to instruct an operator to perform X-ray imaging. When the condition setting instruction is input via the input device 31, the console 16 wirelessly transmits a condition setting signal including the set shooting menu and irradiation conditions to the electronic cassette 15.

The various operation instructions include a shooting instruction of the camera image 63. When the shooting instruction of the camera image 63 is input via the input device 31, the console 16 wirelessly transmits the shooting instruction signal to the camera 23.

The console 16 uses the X-ray image 40 from the electronic cassette 15 as an image file 41 in a format compliant with the DICOM (Digital Imaging and Communication in Medicine) standard as shown in FIG. 2, for example. Then, this is transmitted to a medical image storage communication system (PACS; Picture Archiving and Communication System, not shown).

In the image file 41, the X-ray image 40 and the incidental information 42 are associated with each other by one image ID. The incidental information 42 includes subject information such as the name and gender of the subject H, an order ID, a shooting menu, irradiation conditions, and the like. The order ID is a symbol or number that identifies the shooting order.

In FIG. 3, the electronic cassette 15 is composed of a sensor panel 50, a circuit unit 51, and a rectangular parallelepiped-shaped portable housing 52 that accommodates the sensor panel 50. The housing 52 has a size conforming to the international standard ISO (International Organization for Standardization) 4090: 2001, which is substantially the same as, for example, a film cassette, an IP (Imaging Plate) cassette, and a CR (Computed Radiography) cassette.

A rectangular opening is formed in the front surface 52A of the housing 52, and a transmission plate 53 having X-ray transmission is attached to the opening. The front surface 52A of the electronic cassette 15 is positioned so as to face the X-ray source 13, and the front surface 52A is irradiated with X-rays. Although not shown, the housing 52 also has a switch for switching the main power on / off, an indicator for notifying the operating state of the electronic cassette 15 such as the remaining battery usage time and the shooting ready state. Is provided.

The sensor panel 50 is composed of a scintillator 55 and a photodetector substrate 56. The scintillator 55 and the photodetector substrate 56 are laminated in the order of the scintillator 55 and the photodetector substrate 56 when viewed from the front surface 52A side. The scintillator 55 has a phosphor such as CsI: Tl (thallium-activated cesium iodide) or GOS (Gd ₂ O ₂ S: Tb, terbium-activated gadolinium oxysulfide), and emits X-rays incident through the transmission plate 53. Converts to visible light and emits it. A sensor panel in which the photodetector substrate 56 and the scintillator 55 are laminated in this order when viewed from the front surface 52A to which X-rays are irradiated may be used. Further, a direct conversion type sensor panel that directly converts X-rays into signal charges by a photoconductor such as amorphous selenium may be used.

The photodetection substrate 56 detects visible light emitted from the scintillator 55 and converts it into electric charges. The circuit unit 51 controls the driving of the photodetection board 56 and generates an X-ray image 40 based on the electric charge output from the photodetection board 56.

The light detection substrate 56 is provided with a photographing region RX. The photographing region RX has substantially the same size as the transmission plate 53, and a plurality of pixels are arranged in a two-dimensional matrix of N rows × M columns. The pixels accumulate charges in response to visible light from the scintillator 55. The X-ray image 40 is detected by converting the electric charge accumulated in the pixels into a digital signal in the circuit unit 51.

N and M are integers of 2 or more, for example, N and M≈2000. The number of pixel matrices is not limited to this. Further, the arrangement of the pixels may be a square arrangement, or the pixels may be tilted by 45 ° and the pixels may be arranged in a staggered pattern.

L-shaped markers 57A are arranged at the four corners of the photographing area RX. Further, a rod-shaped marker 57B is arranged at the center of one short side of the photographing region RX. The side on which the rod-shaped marker 57B is arranged is on the upper side in the X-ray image 40. Further, a cross-shaped marker 57C is arranged in the center of the imaging region RX. The marker 57A is formed on the long side side longer than the short side side. These markers 57A to 57C indicate the position and orientation of the imaging region RX.

FIG. 3 shows a state in which the hand of the subject H is placed on the electronic cassette 15 as in FIG. Then, the irradiation field display light LIF (indicated by the hatching of the broken line) is emitted from the irradiation field display light source 22, and the irradiation field IF indicated by the alternate long and short dash line is irradiated by the irradiation field display light LIF.

In this example, the irradiation field IF has the same side corresponding to the wrist of the subject H as the shooting area RX, and the other three sides are parallel to the opposite three sides of the shooting area RX. Further, the irradiation field IF is set to a size one size smaller than the imaging region RX. Therefore, in the imaging region RX, a region other than the irradiation field IF that is not irradiated with X-rays, that is, a non-irradiation field NIF is generated.

In this case, as shown in FIG. 4, the X-ray image 40 output from the electronic cassette 15 corresponds to the irradiation field corresponding portion 60 (indicated by the hatching of the broken line) corresponding to the irradiation field IF and the non-irradiation field NIF. It is divided into the non-irradiated field corresponding part 61 (indicated by the hatching of the solid line). In the X-ray image 40, the portion where the X-ray arrival dose is large is displayed in black. Therefore, the portion 60 corresponding to the irradiation field is displayed in black because it is a portion to which X-rays are irradiated. On the other hand, the non-irradiated field corresponding portion 61 has the maximum brightness because it is a portion not irradiated with X-rays, and is displayed in pure white.

The electronic cassette 15 is provided with a function of detecting the start of X-ray irradiation. In this irradiation start detection function, for example, an irradiation start detection sensor is provided in the photographing region RX of the light detection substrate 56. Then, the dose signal corresponding to the reached dose of X-rays output from the irradiation start detection sensor in a predetermined sampling cycle is compared with the preset irradiation start detection threshold value, and the dose signal exceeds the irradiation start detection threshold value. If so, it is determined that the X-ray irradiation has started. The irradiation start detection sensor is, for example, a part of a pixel.

Further, the electronic cassette 15 has a timer that starts timing when the start of X-ray irradiation is detected, similarly to the control unit 27 of the radiation source control device 14. The electronic cassette 15 determines that the X-ray irradiation has been completed when the time measured by the timer reaches the irradiation time under the irradiation conditions set on the console 16.

As shown in FIG. 5, when the electronic cassette 15 receives the condition setting signal from the console 16, the electronic cassette 15 starts a pixel reset operation of reading dark charges from the pixels and resetting (discarding) them. The electronic cassette 15 is in a standby operation before receiving the condition setting signal. The standby operation is a state in which power is supplied only to the minimum necessary parts such as a wireless communication unit that plays a role of receiving a condition setting signal.

Next, when the electronic cassette 15 detects the start of X-ray irradiation by the irradiation start detection function, it finishes the pixel reset operation and starts the pixel charge accumulation operation of accumulating the electric charge in the pixel according to the arrival dose of the X-ray. To do. As a result, the X-ray irradiation start timing of the X-ray source 13 and the start timing of the pixel charge accumulation operation can be synchronized.

After that, when the electronic cassette 15 detects the end of X-ray irradiation by the timer, it finishes the pixel charge accumulation operation and starts the image reading operation for reading the X-ray image 40 to be used for diagnosis. This completes one X-ray imaging to obtain the X-ray image 40 for one screen. After the image reading operation is completed, the electronic cassette 15 returns to the standby operation again.

FIG. 6 is a camera image 63 showing a state of X-ray photography shown in FIGS. 1 and 3. In the camera image 63, the table 17, the electronic cassette 15 placed on the table 17, the hand of the subject H placed on the electronic cassette 15, and the irradiation field display light LIF from the irradiation field display light source 22 are included. It is reflected.

Since the camera 23 is attached to the X-ray source 13, the positional relationship between the X-ray source 13 and the camera 23 does not change. Therefore, in the camera image 63, the irradiation field display light LIF, and eventually the center of the irradiation field IF, is always located at the same position.

In FIG. 7, the console 16 includes a storage device 65, a memory 66, a CPU (Central Processing Unit) 67, and a communication unit 68 in addition to the display 30 and the input device 31 described above. These are interconnected via a data bus 69.

The storage device 65 is a hard disk drive built in the console 16 or connected via a cable or a network, or a disk array in which a plurality of hard disk drives are connected. The storage device 65 stores control programs such as an operating system, various application programs, and various data associated with these programs.

The memory 66 is a work memory for the CPU 67 to execute a process. The CPU 67 comprehensively controls each part of the console 16 by loading the program stored in the storage device 65 into the memory 66 and executing the processing according to the program. The communication unit 68 is responsible for communicating various data such as the X-ray image 40 and the camera image 63 between the electronic cassette 15 and the camera 23.

In FIG. 8, the operation program 75 is stored in the storage device 65. The operation program 75 is an application program for causing the computer constituting the console 16 to function as an image processing device. When the operation program 75 is activated, the CPU 67 functions as a camera image acquisition unit 80, an X-ray image acquisition unit 81, a detection unit 82, an image processing unit 83, and a display control unit 84 in cooperation with the memory 66 and the like. To do.

The camera image acquisition unit 80 is responsible for the camera image acquisition function of acquiring the camera image 63 from the camera 23. The camera image acquisition unit 80 outputs the acquired camera image 63 to the detection unit 82. The X-ray image acquisition unit 81 corresponds to a radiographic image acquisition unit, and is responsible for an X-ray image acquisition function for acquiring an X-ray image 40 from an electronic cassette 15. The X-ray image acquisition unit 81 outputs the acquired X-ray image 40 to the image processing unit 83.

The detection unit 82 has a detection function of detecting the position of the electronic cassette 15 based on the camera image 63. More specifically, the detection unit 82 applies a well-known image recognition technique such as pattern matching to the camera image 63, and recognizes the markers 57A to 57C on the front surface 52A of the housing 52 of the electronic cassette 15. Then, the position coordinates of the recognized markers 57A to 57C in the camera image 63 are detected as the position of the electronic cassette 15. Since the markers 57A and 57B are arranged along the photographing region RX, the position of the electronic cassette 15 detected by the detection unit 82 is, that is, the position of the photographing region RX. The detection unit 82 outputs the detected position information of the electronic cassette 15 (hereinafter, cassette position information) to the image processing unit 83.

When the marker 57C of this example is obscured by the subject H and is not reflected in the camera image 63, the detection unit 82 does not recognize it as a matter of course. However, if at least one of the four markers 57A can be recognized, the position of the electronic cassette 15 can be detected. In addition, instead of or in addition to the markers 57A to 57C, the contour of the outer circumference of the front surface 52A may be image-recognized.

The detection unit 82 also has a detection function of detecting the position of the irradiation field IF based on the camera image 63. In the present embodiment, the irradiation field display light LIF is irradiated from the irradiation field display light source 22, and the irradiation field display light LIF is reflected in the camera image 63 as shown in FIG. Therefore, in the present embodiment, the detection unit 82 detects the position of the irradiation field IF based on the irradiation field display light LIF. In this case as well, as in the case of the position of the electronic cassette 15, the detection unit 82 recognizes the contour of the outer periphery of the irradiation field display light LIF by a well-known image recognition technique, and determines the position coordinates of the recognized contour in the camera image 63. , Detect as the position of the irradiation field IF. At this time, since the irradiation field display light LIF emits light in a special color, the detection unit 82 recognizes the outline of the outer periphery of the irradiation field display light LIF with reference to the color information. The detection unit 82 outputs the detected irradiation field IF position information (hereinafter, irradiation field position information) to the image processing unit 83.

The image processing unit 83 is responsible for an image processing function of performing image processing based on the cassette position information from the detection unit 82 and the irradiation field position information on the X-ray image 40 from the X-ray image acquisition unit 81. The image processing unit 83 outputs the image-processed X-ray image to the display control unit 84.

The display control unit 84 controls to display the image-processed X-ray image 40 from the image processing unit 83 on the display 30.

As shown in FIG. 9, the image processing unit 83 includes a first image processing unit 83A and a second image processing unit 83B. The first image processing unit 83A identifies the irradiation field corresponding portion 60 of the X-ray image 40 based on the cassette position information and the irradiation field position information from the detection unit 82. Then, the irradiation field corresponding portion 60 is subjected to the first image processing as image processing. On the other hand, the second image processing unit 83B identifies the non-irradiated field corresponding portion 61 of the X-ray image 40, and performs the second image processing as image processing on the non-irradiated field corresponding portion 61.

More specifically, the first image processing unit 83A performs multi-frequency processing and dynamic range compression processing on the irradiation field corresponding portion 60 as the first image processing. Further, the second image processing unit 83B performs a blackening process on the non-irradiated field corresponding portion 61 as the second image processing.

In the multi-frequency processing, first, a plurality of smoothed images are created for the X-ray image 40 before the image processing. Then, a difference image between the smoothed images is obtained, and the non-linear conversion process is performed on the difference image. Next, frequency enhancement is performed using the sum of each difference image that has undergone non-linear conversion processing to emphasize the edges of structures such as bones. Dynamic range compression processing is part of the function of multi-frequency processing. The dynamic range compression processing uses the sum of the difference images that have undergone non-linear conversion processing in the multi-frequency processing to brighten the dark part of the X-ray image 40 to make it easier to see, or conversely, the bright part of the X-ray image 40. It is a process that darkens and makes it easier to see. The blackening treatment is a treatment of painting the non-irradiated field corresponding portion 61 with black.

Next, the operation of the above configuration will be described with reference to the flowcharts of FIGS. 10 and 11. First, the operator sets a desired shooting menu via the input device 31 of the console 16. As a result, a condition setting signal including the set shooting menu and the irradiation conditions corresponding thereto is transmitted from the console 16 to the electronic cassette 15. After setting the shooting menu, the operator sets the same irradiation conditions as the irradiation conditions corresponding to the set shooting menu in the radiation source control device 14 via the touch panel 25. After that, the relative positioning of the X-ray source 13, the electronic cassette 15, and the subject H is started.

For example, in the case of hand photography, as shown in FIG. 1, the operator places the electronic cassette 15 on the table 17, places the hand of the subject H on the electronic cassette 15, and further shoots the X-ray source 13 as the subject. Set it just above H's hand. At this time, the operator sets the size of the irradiation aperture of the irradiation field limiting device 21, that is, the irradiation field IF, in the radiation source control device 14 via the touch panel 25.

The operator operates the irradiation field display light source 22 to irradiate the irradiation field display light LIF toward the electronic cassette 15. Using the irradiation field display light LIF as a clue, the operator fine-tunes these positions so that the positional relationship between the X-ray source 13, the electronic cassette 15, and the subject H becomes desired.

After the positioning is completed, the operator inputs a shooting instruction of the camera image 63 via the input device 31 of the console 16. As a result, the shooting instruction signal of the camera image 63 is wirelessly transmitted from the console 16 to the camera 23.

The camera 23 takes a camera image 63 in response to a shooting instruction signal from the console 16. The camera image 63 is wirelessly transmitted from the camera 23 to the console 16.

As shown in step ST100 of FIG. 10, the camera image 63 from the camera 23 is acquired by the camera image acquisition unit 80 (camera image acquisition step). The camera image 63 is output from the camera image acquisition unit 80 to the detection unit 82.

The operator operates the irradiation switch 28 to generate X-rays from the X-ray source 13. The X-rays emitted from the X-ray source 13 and transmitted through the subject H are applied to the front surface 52A of the electronic cassette 15. As a result, the X-ray image 40 is detected by the electronic cassette 15. The X-ray image 40 is wirelessly transmitted from the electronic cassette 15 to the console 16.

As shown in step ST110, the X-ray image 40 from the electronic cassette 15 is acquired by the X-ray image acquisition unit 81 (corresponding to the X-ray image acquisition step and the radiographic image acquisition step). The X-ray image 40 is output from the X-ray image acquisition unit 81 to the image processing unit 83.

As shown in step ST120, the detection unit 82 detects the position of the electronic cassette 15 and the position of the irradiation field IF based on the camera image 63 from the camera image acquisition unit 80 (detection step). The cassette position information, which is the position information of the detected electronic cassette 15, and the irradiation field position information, which is the position information of the irradiation field IF, are output to the image processing unit 83.

As shown in step ST130, the image processing unit 83 performs image processing based on the cassette position information from the detection unit 82 and the irradiation field position information on the X-ray image 40 from the X-ray image acquisition unit 81. (Image processing step).

FIG. 11 shows a series of flow of image processing steps by the image processing unit 83. As shown in FIG. 9, the first image processing unit 83A performs multi-frequency processing and dynamic range compression processing on the irradiation field corresponding portion 60 as the first image processing (step ST1301). Next, the second image processing unit 83B performs a blackening process on the non-irradiated field corresponding portion 61 as the second image processing (step ST1302). The image-processed X-ray image 40 subjected to such image processing is output from the image processing unit 83 to the display control unit 84. The order of the first image processing in step ST1301 and the second image processing in step ST1302 may be reversed.

In step ST140 of FIG. 10, the image-processed X-ray image 40 is displayed on the display 30 by the display control unit 84. The X-ray image 40 is further converted into an image file 41 by the console 16 and transmitted to the PACS for viewing by the photographer.

The console 16 does not detect the position of the irradiation field IF by image analysis of the X-ray image 40 as in the conventional case, but detects the position of the irradiation field IF based on the camera image 63 output from the camera 23. To do. Therefore, it is possible to detect the position of the irradiation field IF more accurately than the detection based on the X-ray image 40 in which the contour of the irradiation field IF may not be clear. Then, based on the information on the position of the irradiation field IF detected in this way, it is possible to perform appropriate image processing on the X-ray image 40.

The effect of the present invention will be further described in comparison with a conventional example of image analysis of an X-ray image 40. As shown in FIG. 12A, the irradiation field IF is set obliquely with respect to the imaging area RX so that each side of the irradiation field IF and each side of the imaging area RX are not parallel, and a relatively linear component such as an arm is set. Consider the case where the imaging site contains a large amount of.

In the conventional image analysis of the X-ray image 40, for example, a portion where the pixel value changes rapidly is extracted as a boundary between the irradiated field IF and the non-irradiated field NIF. Then, the rectangular region formed by the extracted boundary is detected as an irradiation field. Therefore, when the irradiation field IF is not rectangular as shown in FIG. 12A, it is difficult to detect the position of the irradiation field IF.

Further, as shown in FIG. 12B, when the imaging site is the arm, there are many linear components such as the contour 90 of the arm and the contour 91 of the bone (ulna and radius). Since these contours 90 and 91 are also portions where the pixel values change rapidly, it is easy to mistakenly extract the boundary between the irradiated field IF and the non-irradiated field NIF. Further, since these contours 90 and 91 are linear, the possibility of erroneously extracting the boundary between the similarly linear irradiated field IF and the non-irradiated field NIF is further increased.

On the other hand, in the present invention for detecting the position of the irradiation field IF based on the camera image 63 output from the camera 23, the position of the irradiation field IF can be detected independently of the X-ray image 40. As shown in 12, the irradiation field IF is set diagonally with respect to the imaging region RX, and even when the imaging region contains a relatively large amount of linear components, it is possible to detect the accurate position of the irradiation field IF. is there.

That is, since the detection unit 82 detects the position of the irradiation field IF based on the irradiation field display light LIF from the irradiation field display light source 22 reflected in the camera image 63, the irradiation field can be easily detected by using a well-known image recognition technique. The position of the IF can be detected. Since the irradiation field display light source 22 is standard equipment on many X-ray sources, the existing equipment can be effectively utilized.

Since the first image processing unit 83A performs multi-frequency processing and dynamic range compression processing on the irradiation field corresponding portion 60 of the X-ray image 40, the edges of structures such as bones are emphasized and the contrast is adjusted as a whole. , An X-ray image 40 having an image quality suitable for diagnosis can be obtained. Further, since these first image processings need to be performed only on the irradiation field corresponding portion 60, the processing load of the first image processing unit 83A can be reduced.

Further, since the second image processing unit 83B applies the blackening process to the non-irradiated field corresponding portion 61, the non-irradiated field corresponding portion 61 is not displayed in white and interferes with the observation.

The second image processing applied to the non-irradiated field corresponding portion 61 is not limited to the above blackening treatment. As in the second image processing unit 95B of the image processing unit 95 shown in FIG. 13, a trimming process may be performed in which the non-irradiation field corresponding portion 61 is removed and only the irradiation field corresponding portion 60 is left. In this case as well, since the non-irradiated field corresponding portion 61 itself is removed as in the blackening treatment, the non-irradiated field corresponding portion 61 is not displayed in white and interferes with the observation.

Although the first image processing unit 95A has a different reference numeral for convenience, the function is the same as that of the first image processing unit 83A.

[Second Embodiment]
In the second embodiment shown in FIGS. 14 and 15, the size of the irradiation field IF in the camera image 63 at the time of X-ray imaging (hereinafter, the size in the image) is calculated.

In FIG. 14, in the CPU 67 of the console 16 of the present embodiment, in addition to the respective units 80, 81, 83, 84 (not shown in FIG. 14) shown in FIG. 8 of the first embodiment, the first acquisition unit 100 And the second acquisition unit 101 are provided. Further, a detection unit 102 is provided instead of the detection unit 82. Hereinafter, the functions of the first acquisition unit 100, the second acquisition unit 101, and the detection unit 102 will be described with reference to FIG.

The first acquisition unit 100 determines the irradiation field IF0 in the camera image 63 at a preset reference distance SID (Source to Image receptor Distance) 0 with the focal position FP of the X-ray tube 20 of the X-ray source 13 as an end point. Acquire the reference size (hereinafter, the size in the reference image) LIM0.

More specifically, the first acquisition unit 100 first acquires the sizes x and y of the irradiation aperture (length and width of the irradiation aperture) of the irradiation field limiting device 21 at the time of X-ray imaging. Then, based on the calculation formula 103 (LIM0 = F (x, y)) stored in the storage device 65, the size LIM0 in the reference image corresponding to the acquired irradiation aperture sizes x and y is acquired. The calculation formula 103 is a function of the size LIM0 in the reference image with the sizes x and y of the irradiation aperture as variables. The first acquisition unit 100 acquires the size LIM0 in the reference image by substituting the acquired irradiation aperture sizes x and y into the calculation formula 103 for calculation. The first acquisition unit 100 outputs the acquired reference image size LIM0 and the reference distance SID0 to the detection unit 102.

Here, the size LIM0 in the reference image is the vertical and horizontal length X0 of the irradiation field IF0 projected on a plane whose normal line is the line connecting the focal position FP and the point CP0 separated from the focal position FP by the reference distance SID0. , Y0.

The second acquisition unit 101 acquires the distance SID1 between the focal position FP and the imaging area RX at the time of X-ray imaging. The distance SID1 is the length of a perpendicular line drawn from the focal position FP to the photographing area RX. The second acquisition unit 101 outputs the acquired distance SID1 to the detection unit 102.

The detection unit 102 is within the image of the irradiation field IF1 in the camera image 63 at the time of X-ray photography from the reference image size LIM0 and the reference distance SID0 from the first acquisition unit 100 and the distance SID1 from the second acquisition unit 101. Calculate the size LIM1. That is, the in-image size LIM1 is obtained by calculation using the similarity ratio SID1 / SID0 shown in the following formula (1).

LIM1 = (SID1 / SID0) ・ LIM0 ... (1)
Similar to the reference image size LIM0, the in-image size LIM1 is also the vertical and horizontal directions of the irradiation field IF1 projected on a plane whose normal line is the line connecting the focal position FP and the point CP1 at a distance SID1 from the focal position FP. The lengths are X1 and Y1. Therefore, the above equation (1) is rewritten into the following equations (2) and (3).

X1 = (SID1 / SID0) ・ X0 ... (2)
Y1 = (SID1 / SID0) · Y0 ... (3)
For example, when the reference distance SID0 = 5 m, X0 = 1 m, Y0 = 50 cm and the distance SID1 = 2.5 m, the similarity ratio is SID1 / SID0 = 2.5 / 5 = 0.5, so X1 = 50 cm. , Y1 = 25 cm.

The detection unit 102 converts the calculated in-image size LIM1 into the position coordinates of the contour of the irradiation field IF1 in the camera image 63. Then, the converted position coordinates are output to the image processing unit 83 as irradiation field position information. Since the subsequent processing is the same as that of the first embodiment, the description thereof will be omitted.

In this way, the size LIM0 in the reference image of the irradiation field IF0 in the camera image 63 at the reference distance SID0 and the distance SID1 between the focal position FP and the shooting area RX at the time of X-ray photography are acquired, and the size in the reference image. Since the in-image size LIM1 of the irradiation field IF1 in the camera image 63 at the time of X-ray photography is calculated from the LIM0, the reference distance SID0, and the distance SID1, the irradiation field display light source 22 fails and the irradiation field display light LIF The position of the irradiation field IF1 can be detected without any problem even when the irradiation field cannot be irradiated or the X-ray source does not incorporate the irradiation field display light source 22 itself.

The sizes x and y of the irradiation aperture at the time of X-ray photography are input directly to the console 16 by the operator via the input device 31, for example. Alternatively, the radiation source control device 14 may transmit the sizes x and y of the irradiation aperture at the time of X-ray photography to the console 16.

Similarly, the operator inputs the distance SID1 between the focal position FP and the imaging area RX at the time of X-ray imaging directly into the console 16 via the input device 31. Alternatively, a distance measurement sensor for measuring the distance SID1 may be attached to the X-ray source 13, and the measured distance SID1 may be transmitted from the distance measurement sensor to the console 16. As the distance measurement sensor, a Time of Flight camera, an ultrasonic sensor, a radar sensor, or the like can be used.

Further, the distance SID 1 may be obtained based on the size of the electronic cassette 15 displayed in the camera image 63. In this case, the size of the electronic cassette 15 displayed on the camera image 63 at the reference distance SID 0 is stored in the storage device 65 in advance. Then, the SID1 is obtained by calculation using the similarity ratio in the same manner as the in-image size LIM1 of the irradiation field IF1 in the camera image 63 at the time of X-ray photography.

The size LIM0 in the reference image corresponding to the sizes x and y of the irradiation aperture is calculated by the calculation formula 103, but the present invention is not limited to this. The size LIM0 in the reference image corresponding to the sizes x and y of the irradiation aperture may be stored in the storage device 65 as a data table. In this case, the first acquisition unit 100 reads out the reference image size LIM0 corresponding to the acquired irradiation aperture sizes x and y from the data table of the storage device 65.

[Third Embodiment]
In the third embodiment shown in FIG. 16, the information of the irradiation field corresponding portion is associated with the X-ray image 40 as incidental information 42 of the X-ray image 40.

In FIG. 16, the CPU 67 of the console 16 of the present embodiment is provided with an association processing unit 110 in addition to the units 80 to 84 (only the detection unit 82 is shown) shown in FIG. 8 of the first embodiment.

The detection unit 82 outputs the cassette position information and the irradiation field position information to the association processing unit 110. The association processing unit 110 identifies the irradiation field corresponding portion 60 of the X-ray image 40 based on the cassette position information and the irradiation field position information from the detection unit 82. The association processing unit 110 includes the information of the specified irradiation field corresponding portion 60 (hereinafter, irradiation field corresponding portion information) in the incidental information 42 of the image file 41. The irradiation field corresponding portion information is specifically the position coordinates of the irradiation field corresponding portion 60 in the X-ray image 40.

In this way, since the irradiation field corresponding portion information is associated with the X-ray image 40 as incidental information 42, image processing is performed on the irradiation field corresponding portion 60 with a device other than the console 16, for example, a client terminal of a shooting requester. When applying, the irradiation field corresponding part information can be referred to.

Instead of the irradiation field corresponding part information, the non-irradiation field corresponding part information which is the information of the non-irradiation field corresponding part 61 may be associated with the X-ray image 40 as incidental information 42. Further, although FIG. 16 illustrates the detection unit 82 of the first embodiment, the detection unit 102 of the second embodiment may also be used.

The image processing unit may include at least one of the first image processing unit and the second image processing unit.

The camera image 63 may be captured as a moving image, and the position of the electronic cassette 15 and the position of the irradiation field IF may be detected based on the camera image 63 captured immediately before the start of X-ray irradiation.

In each of the above embodiments, the camera image 63 is used only for detecting the position of the electronic cassette 15 and the position of the irradiation field IF. However, a moving image is taken as the camera image 63, and the operator uses the X-ray source 13, When the electronic cassette 15 and the subject H are relatively positioned, the camera image 63 may be displayed on the display 30 to assist the positioning.

In each of the above embodiments, for example, the camera image acquisition unit 80, the X-ray image acquisition unit 81, the detection units 82, 102, the image processing units 83, 95 (first image processing units 83A, 95A, second image processing unit 83B, The hardware structure of the processing unit that executes various processes such as the display control unit 84, the first acquisition unit 100, the second acquisition unit 101, and the association processing unit 110 is as shown below. Various processors.

Various processors include a CPU, a programmable logic device (PLD), a dedicated electric circuit, and the like. As is well known, a CPU is a general-purpose processor that executes software (program) and functions as various processing units. PLD is a processor such as FPGA (Field Programmable Gate Array) whose circuit configuration can be changed after manufacturing. A dedicated electric circuit is a processor having a circuit configuration specially designed for executing a specific process such as an ASIC (Application Specific Integrated Circuit).

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 type or different types (for example, a plurality of FPGAs or a combination of a CPU and an FPGA). May be done. Further, a plurality of processing units may be configured by one processor. As an example of configuring a plurality of processing units with one processor, first, 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. .. Secondly, as typified by System On Chip (SoC) and the like, 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 chip is used. As described above, the various processing units are configured by using one or more of the above-mentioned various processors as a hardware-like structure.

Further, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

From the above description, the image processing apparatus according to the following appendix 1 can be grasped.

[Appendix 1]
A radiation image acquisition processor that acquires a radiation image detected by an electronic cassette, which is a radiation image based on the radiation emitted from a radiation source and transmitted through the subject.
A camera image acquisition processor attached to the radiation source and acquiring at least a camera image output from a camera that captures the electronic cassette.
A detection processor that detects the position of the electronic cassette and the position of the irradiation field, which is the area where the radiation is irradiated, based on the camera image.
An image processing device including an image processing processor that performs image processing on the radiation image based on the information on the position of the electronic cassette and the information on the position of the irradiation field.

In each of the above embodiments, the case where free photography is performed using the X-ray imaging system 10 provided in the imaging room has been illustrated, but there is a bed for the subject H using a round-trip car which is a portable X-ray generator. The present invention is also applicable to free radiography in a hospital room.

The present invention can be applied not only to X-rays but also to the case of using other radiation such as γ-rays.

It goes without saying that the present invention is not limited to each of the above embodiments, and various configurations can be adopted as long as the gist of the present invention is not deviated. Further, the present invention extends to a storage medium for storing a program in addition to the program.

10 X-ray imaging system 11 X-ray generator 12 X-ray imaging device 13 X-ray source (radioactive source)
14 Radioactive source control device 15 Electronic cassette 16 Console (image processing device)
20 X-ray tube 21 Irradiation field limiter 22 Irradiation field display light source 23 Camera 25 Touch panel 26 Voltage generator 27 Control unit 28 Irradiation switch 30 Display 31 Input device 40 X-ray image (radiation image)
41 Image file 42 Ancillary information 50 Sensor panel 51 Circuit part 52 Housing 52A Front 53 Transmission plate 55 Scintillator 56 Photodetector board 57A to 57C Marker 60 Irradiation field applicable part 61 Non-irradiation field applicable part 63 Camera image 65 Storage device 66 Memory 67 CPU
68 Communication unit 69 Data bus 75 Operation program 80 Camera image acquisition unit 81 X-ray image acquisition unit (Radiation image acquisition unit)
82, 102 Detection unit 83, 95 Image processing unit 83A, 95A First image processing unit 83B, 95B Second image processing unit 84 Display control unit 90 Arm contour 91 Bone contour 100 First acquisition unit 101 Second acquisition unit 103 Calculation formula 110 Association processing unit H Subject LIF Irradiation field Display light FOV Camera field view IF, IF0, IF1 Irradiation field NIF Non-irradiation field RX Shooting area ST100 to ST140, ST1301, ST1302 Step FP X-ray tube focus position x, y X Size of irradiation aperture during radiography SID0 Reference distance SID1 Distance between focal position and radiography area during X-ray photography LIM0 Reference image size LIM1 Irradiation field image size in camera image during X-ray photography CP0, CP1 Points X0, Y0, X1, Y1 Vertical and horizontal lengths of the irradiation field

Claims (11)

A camera image acquisition unit that is attached to a radiation source and acquires at least a camera image output from a camera that shoots a subject.
A detection unit that detects a portion corresponding to the irradiation field and a portion corresponding to the non-irradiation field in the radiation image based on the radiation emitted from the radiation source and transmitted through the subject based on the camera image.
An image processing apparatus including an image processing unit that performs image processing on the radiation image based on the irradiation field corresponding portion and the non-irradiation field corresponding portion. The irradiation field corresponding portion is a portion of the radiation corresponding to the irradiation field which is the region where the radiation is irradiated.
The image processing apparatus according to claim 1, wherein the non-irradiated field corresponding portion is a portion of the radiation corresponding to the non-irradiated field which is a region other than the irradiated field where the radiation is not irradiated. The radiation source has an irradiation field display light source that emits irradiation field display light indicating the irradiation field.
The image processing device according to claim 2, wherein the detection unit detects the position of the irradiation field based on the irradiation field display light reflected in the camera image. The electronic cassette for detecting the radiographic image is provided with a photographing region for detecting the radiological image.
A first acquisition unit that acquires the reference size LIM0 of the irradiation field in the camera image at a preset reference distance SID0 with the focal position of the radiation tube of the radiation source as an end point.
A second acquisition unit for acquiring the distance SID1 between the focal position and the imaging area at the time of radiography is provided.
The detection unit uses the reference size LIM0 acquired by the first acquisition unit, the reference distance SID0, and the distance SID1 acquired by the second acquisition unit in the camera image at the time of radiography. The image processing apparatus according to claim 2 or 3, which calculates the size LIM1 of the irradiation field. The radiation source is provided with an irradiation field limiter having an irradiation aperture for setting the irradiation field.
The image processing apparatus according to claim 4, wherein the first acquisition unit acquires the size of the irradiation opening at the time of radiography, and acquires the reference size LIM0 corresponding to the acquired size of the irradiation opening. .. The image processing unit performs a first image processing as the image processing on the irradiation field corresponding portion, or / and a second image processing as the image processing on the non-irradiation field corresponding portion. The image processing apparatus according to any one of claims 1 to 5, which includes a second image processing unit to be applied. The image processing apparatus according to claim 6, wherein the first image processing unit performs multi-frequency processing and dynamic range compression processing on the irradiation field corresponding portion as the first image processing. As the second image processing, the second image processing unit performs a blackening process in which the non-irradiated field applicable portion is painted in black, or a trimming process in which the non-irradiated field applicable portion is removed and only the irradiation field applicable portion is left. The image processing apparatus according to claim 6 or 7, wherein the processing is performed. The item according to any one of claims 6 to 8, further comprising an association processing unit that associates information of either the irradiation field applicable portion or the non-irradiation field applicable portion with the radiation image as incidental information of the radiation image. Image processing device. A camera image acquisition step that is attached to a radiation source and at least acquires a camera image output from a camera that captures the subject.
A detection step of detecting a portion corresponding to the irradiation field and a portion corresponding to the non-irradiation field in the radiation image based on the radiation emitted from the radiation source and transmitted through the subject based on the camera image.
A method of operating an image processing apparatus including an image processing step of performing image processing on the radiation image based on the irradiation field corresponding portion and the non-irradiation field corresponding portion. A camera image acquisition function that is attached to a radiation source and acquires at least the camera image output from the camera that shoots the subject,
Based on the camera image, a detection function that detects a portion corresponding to the irradiation field and a portion corresponding to the non-irradiation field in the radiation image based on the radiation emitted from the radiation source and transmitted through the subject.
An operation program of an image processing device that causes a computer to execute an image processing function for performing image processing on the radiation image based on the irradiation field corresponding portion and the non-irradiation field corresponding portion.

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