JP2019141193A - Radiographic system and console - Google Patents

Abstract

To make it possible to restrain signal values or contrasts of radiographed video images from becoming uneven because different imaging devices are used.SOLUTION: According to a radiographic system 100, a control unit 21 creates a plurality of correction tables for correcting signal values of each frame image of video images acquired with an imaging device 1 to signal values acquired by video-shooting the same subject under a reference imaging condition with a reference imaging device stored in a storage unit 22, on the basis of a plurality of frame images of reference phantom images acquired by video-shooting a reference phantom with the imaging device 1 and plurality of frame images of reference images acquired by video-shooting the reference phantom under the reference imaging condition with the reference imaging device.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a radiation imaging system and a console.

  Conventionally, analysis results obtained by quantitatively analyzing a radiographic image obtained by radiographing a living body (numerical analysis of signal values) have been used as diagnostic judgment materials. In quantitative analysis of radiographic images, the signal value of the analysis result is very important.

  However, the radiographic apparatus has different tube specific filtration, additional filter, irradiation field diaphragm or X-ray movable diaphragm material, and the same imaging conditions (tube voltage: kV, dose: mAs, etc.). However, the dose and radiation quality that are actually output may differ depending on the imaging device. If this happens, there will be variations in the signal values of radiographic images taken under the same imaging conditions (signal values when imaging the same object) and contrast, patient analysis results themselves, changes over time, and the extent of analysis results with other patients It is difficult to compare whether the two are different, and the analysis result does not help the diagnosis.

  For example, a reference phantom F such as an aluminum member (aluminum step; see FIG. 2) whose thickness is 20 cm in the longitudinal direction and has a maximum thickness of 2 cm and a thickness of 20 mm by 1 mm is irradiated. 4A, when the signal value shown in FIG. 4A is obtained, if the radiation quality is changed and radiation with energy lower than the reference is irradiated, the radiation is easily absorbed by aluminum. As shown in b), the contrast of the signal value increases. Further, when radiation having a higher energy than the reference is irradiated, the radiation is not easily absorbed by aluminum, so that the signal value contrast becomes small as shown in FIG. Further, as the radiation dose increases, the signal value representing aluminum in the same step (thickness) increases.

In view of this, a technique has been proposed for correcting variations in signal values of radiographic images and contrast due to variations between apparatuses.
For example, in Patent Document 1, in a bone mineral quantitative analysis system for obtaining a bone mineral quantity of a bone part using a radiographic image of the bone part, prior to obtaining the bone mineral quantity, a radiation tube is set as a reference tube. A radiographic image of a standard substance is acquired by driving with a plurality of tube voltages including a voltage, and concentration gradients relating to at least two portions having different radiation transmission characteristics of the standard material are obtained from the obtained radiographic images. Radiation for obtaining bone mineral quantification based on the relationship between the concentration gradient in the radiographic image taken for obtaining bone mineral quantification and the concentration gradient when photographed at the reference tube voltage. It is described that an image or a bone mineral quantitative analysis result is corrected to a case where the result is taken at a reference tube voltage.

JP 2013-150762 A

  By the way, in recent years, it has been proposed to quantitatively analyze a moving image obtained by taking a moving image of the dynamics of a living body using radiation. In moving image shooting, since a plurality of frame images (for example, 300 images) are continuously irradiated (or a large number in a short time), a tube target or A phenomenon occurs in which the state of the filament changes and the dose and radiation quality of the output radiation change during imaging.

  However, since the technique described in Patent Document 1 is intended for a radiographic image obtained by still image shooting, a phenomenon peculiar to moving images in which the dose and quality of radiation to be output change during shooting is taken into consideration. Correction cannot be performed.

  An object of the present invention is to make it possible to suppress variations in signal values and contrast of moving images taken by radiography due to different imaging devices.

In order to solve the above-mentioned problem, the invention described in claim 1
A radiation imaging system comprising imaging means for acquiring a moving image by irradiating a subject with radiation and capturing a moving image,
Storage means for storing a reference image obtained by shooting a moving image under a reference phantom with a reference shooting condition by a reference shooting device;
Each frame of the moving image obtained by the photographing means using a plurality of frame images of the reference phantom image obtained by taking a moving image of the reference phantom by the photographing means and a plurality of frame images of the reference image. Generating means for generating a plurality of correction data for correcting the signal value of the image;
Correction means for correcting the signal value of each frame image of the moving image using the correction data generated by the generation means;
Is provided.

The invention according to claim 2 is the invention according to claim 1,
The photographing means simultaneously shoots the subject and the reference phantom as moving images, and generates the correction data in the generation means using the obtained plurality of frame images of the reference phantom image and the plurality of frame images of the reference image. The control means to be provided is provided.

The invention according to claim 3 is the invention according to claim 1,
Before or after taking the moving image of the subject by the shooting means, the reference phantom is taken as a moving picture, and the generation means is used by using a plurality of frame images of the reference phantom image and a plurality of frame images of the reference image obtained. Control means for generating the correction data is provided.

The invention according to claim 4 is the invention according to claim 1,
The storage means stores a plurality of reference images obtained by shooting the reference phantom with a plurality of shooting conditions with the reference shooting device,
The photographing means is used to shoot the reference phantom under the plurality of photographing conditions, and the plurality of frame images of the obtained plurality of reference phantom images and the same photographing conditions as when the reference phantom image is photographed. Using the plurality of frame images of the reference image taken as a moving image, the generation unit generates the correction data for each of a plurality of shooting conditions and stores the correction data in the storage unit, and the shooting unit captures the subject as a moving image. And a control means for correcting the signal value of each frame image of the moving image based on the correction data corresponding to the photographing condition when the subject is photographed by the correcting means.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
The generation means generates one correction data for each frame image of the moving image.

The invention according to claim 6 is the invention according to any one of claims 1 to 4,
The generation unit generates one correction data for each of a plurality of frame images that are not all of the moving images.

The invention according to claim 7 is the invention according to any one of claims 1 to 6,
Quantitative analysis means for performing quantitative analysis on the moving image whose signal value has been corrected by the correction means.

The invention according to claim 8 is the invention according to claim 7,
When performing a quantitative analysis on the moving image, the correcting unit uses the plurality of correction data generated by the generating unit for each frame image of the moving image or for each of a plurality of frame images. When the signal value of each frame image is corrected and the moving image is not subjected to quantitative analysis, the moving image is generated using a single correction data common to all the frame images of the moving image generated by the generating unit. The signal value of each frame image of the image is corrected.

The invention according to claim 9 is the invention according to any one of claims 1 to 8,
The photographing means can further acquire a still image by irradiating a subject with radiation and photographing a still image,
The generation means includes first generation means for generating correction data for correcting a signal value of each frame image of the moving image acquired when moving image shooting is performed by the shooting means; and the shooting means The second generation means for generating correction data for correcting the signal value of the still image acquired when still image shooting is performed by:
When the moving image is shot by the shooting unit, the correction unit corrects the signal value of each frame image of the moving image using the correction data generated by the first generation unit, and When still image shooting is performed by the shooting unit, the signal value of the still image is corrected using the correction data generated by the second generation unit.

The invention according to claim 10 is:
A console for correcting a moving image obtained by shooting a moving image by irradiating a subject with radiation,
Storage means for storing a reference image obtained by shooting a moving image under a reference phantom with a reference shooting condition by a reference shooting device;
Each frame of the moving image obtained by the photographing means using a plurality of frame images of the reference phantom image obtained by taking a moving image of the reference phantom by the photographing means and a plurality of frame images of the reference image. Generating means for generating a plurality of correction data for correcting the signal value of the image;
Correction means for correcting the signal value of each frame image of the moving image using the correction data generated by the generation means;
Is provided.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress that the signal value and contrast of the moving image image | photographed by radiography by different imaging | photography apparatuses differ.

It is a figure showing the whole radiation imaging system composition in an embodiment of the present invention. It is a figure which shows an example of a reference | standard phantom. It is a flowchart which shows the imaging | photography control processing A performed by the control part of the imaging | photography console in 1st Embodiment. (A) is a figure which shows an example of the signal value obtained when the reference | standard phantom is irradiated with the radiation of the reference | standard energy, and the radiograph is taken, (b) irradiates the radiation of energy lower than the reference | standard energy. The figure which shows an example of the signal value obtained when radiography is carried out, (c) is a figure which shows an example of the signal value obtained when the radiographing is performed by irradiating radiation with energy higher than the reference energy. It is a flowchart which shows the imaging | photography control process B performed by the control part of the imaging | photography console in 2nd Embodiment. It is a flowchart which shows the correction table production | generation process performed by the control part of the imaging | photography console in 3rd Embodiment. It is a flowchart which shows the imaging | photography control processing C performed by the control part of the imaging console in 3rd Embodiment. It is a flowchart which shows the imaging | photography condition adjustment process performed by the control part of the imaging | photography console in 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

<First Embodiment>
[Configuration of Radiation Imaging System 100]
First, the configuration of the first embodiment of the present invention will be described.
FIG. 1 shows an overall configuration of a radiation imaging system 100 in the present embodiment.
As shown in FIG. 1, a radiography system 100 includes an imaging apparatus 1 and an imaging console 2 connected by a communication cable or the like, and the imaging console 2 and the diagnostic console 3 are connected to a LAN (Local Area Network) or the like. And connected via a communication network NT. Each device constituting the radiation imaging system 100 conforms to the DICOM (Digital Image and Communications in Medicine) standard, and communication between the devices is performed in accordance with DICOM.

[Configuration of the photographing apparatus 1]
The imaging device 1 is, for example, an imaging unit that acquires a radiographic image by radiographing a subject part of a human body. The photographing apparatus 1 can take a still image or a moving image. For example, the imaging device 1 captures a moving image of the dynamics of a subject having periodicity (cycle), such as changes in the form of lung expansion and contraction associated with respiratory motion, heart pulsation, and the like. In movie shooting, X-rays and other radiations are pulsed and irradiated repeatedly at predetermined time intervals (pulse irradiation), or at a low dose rate and continuously irradiated (continuous irradiation). Thus, a plurality of images showing the dynamics of the subject are acquired. A series of images obtained by moving image shooting is called a moving image. Each of the plurality of images constituting the moving image is called a frame image. In the following embodiments, the imaging device 1 will be described as imaging the chest. In the moving image shooting, a case where moving image shooting is performed by pulse irradiation will be described as an example.

The radiation source 11 is disposed at a position facing the radiation detection unit 13 across the subject M, and irradiates the subject M with radiation (X-rays) according to the control of the radiation irradiation control device 12.
The radiation irradiation control device 12 is connected to the imaging console 2 and controls the radiation source 11 based on the radiation irradiation conditions input from the imaging console 2 to perform radiation imaging. The radiation irradiation conditions input from the imaging console 2 are, for example, pulse rate, pulse width, pulse interval, imaging time per imaging, tube current value, tube voltage value, SID (Source to Image-receptor Distance). , Etc. The pulse rate is the number of times of radiation irradiation per second, and matches the frame rate described later. The pulse width is a radiation irradiation time per one irradiation. The pulse interval is a time from the start of one radiation irradiation to the start of the next radiation irradiation, and coincides with a frame interval described later.

The radiation detection unit 13 includes a semiconductor image sensor such as an FPD (Flat Panel Detector). The FPD has, for example, a glass substrate or the like, detects radiation that has been irradiated from the radiation source 11 and transmitted through at least the subject M at a predetermined position on the substrate according to its intensity, and detects the detected radiation as an electrical signal. A plurality of detection elements (pixels) converted and stored in a matrix are arranged in a matrix. Each pixel includes a switching unit such as a TFT (Thin Film Transistor). The FPD includes an indirect conversion type in which X-rays are converted into electric signals by a photoelectric conversion element via a scintillator, and a direct conversion type in which X-rays are directly converted into electric signals, either of which may be used.
The radiation detection unit 13 is provided to face the radiation source 11 with the subject M interposed therebetween.

  The reading control device 14 is connected to the imaging console 2. The reading control device 14 controls the switching unit of each pixel of the radiation detection unit 13 based on the image reading condition input from the imaging console 2 to switch the reading of the electrical signal accumulated in each pixel. Then, the image data is acquired by reading the electrical signal accumulated in the radiation detection unit 13. This image data is a frame image. The reading control device 14 outputs the acquired frame image to the photographing console 2. The image reading conditions are, for example, shooting time (accumulation time), frame rate, frame interval, pixel size, image size (matrix size), and the like. The frame rate is the number of frame images acquired per second and matches the pulse rate. The frame interval is the time from the start of one frame image acquisition operation to the start of the next frame image acquisition operation, and coincides with the pulse interval.

  Here, the radiation irradiation control device 12 and the reading control device 14 are connected to each other, and exchange synchronization signals to synchronize the radiation irradiation operation and the image reading operation.

[Configuration of the shooting console 2]
The imaging console 2 outputs radiation irradiation conditions and image reading conditions to the imaging apparatus 1 to control radiation imaging (moving image imaging and still image imaging) and radiographic image reading operation by the imaging apparatus 1, and also by the imaging apparatus 1. The acquired radiographic image (moving image, still image) is subjected to various correction processes including a signal value correction process and transmitted to the diagnostic console 3.
As shown in FIG. 1, the imaging console 2 includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25, and each unit is connected by a bus 26.

The control unit 21 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. The CPU of the control unit 21 reads out the system program and various processing programs stored in the storage unit 22 in accordance with the operation of the operation unit 23, expands them in the RAM, and performs shooting control processing A described later according to the expanded programs. And various other processes are executed to centrally control the operation of each part of the imaging console 2, the radiation irradiation operation and the reading operation of the imaging apparatus 1, and the radiographic image (moving image, still image) obtained by the imaging apparatus 1. ) Are subjected to various correction processes.
The control unit 21 functions as a generation unit, a correction unit, and a control unit.

  The storage unit 22 is configured by a nonvolatile semiconductor memory, a hard disk, or the like. The storage unit 22 stores various programs executed by the control unit 21 and data such as parameters necessary for execution of processing by the programs or processing results. For example, the storage unit 22 stores a program for executing the shooting control process A shown in FIG. The storage unit 22 stores imaging conditions (radiation irradiation conditions and image reading conditions) for still image shooting and moving image shooting of the chest. Various programs are stored in the form of readable program code, and the control unit 21 sequentially executes operations according to the program code.

  The storage unit 22 stores imaging order information transmitted from an RIS (Radiology Information System) (not shown) or the like. The imaging order information includes patient information (eg, patient ID, patient name, height, weight, age, sex, etc.), examination information (eg, examination ID, examination date, subject part (here, chest), Distinction between still image shooting and moving image shooting, presence / absence of quantitative analysis, etc.).

  Further, the storage unit 22 includes a reference image for still image shooting that represents a signal value when the reference phantom is radiographed (still image shooting) with the reference shooting device under the reference shooting conditions, and the reference shooting device sets the reference. And a reference image for moving image shooting representing a signal value in each frame image when the phantom is radiographed (moving image shooting) with reference shooting conditions. The reference phantom is, for example, an aluminum member (aluminum step) having a length of 20 cm in the longitudinal direction and a maximum thickness of 2 cm and changing in thickness by 20 steps by 1 mm, as shown in FIG. The reference image is previously stored in the storage unit 32 when the photographing console 2 is shipped.

  The operation unit 23 includes a keyboard having a cursor key, numeric input keys, various function keys, and the like, and a pointing device such as a mouse. The control unit 23 controls an instruction signal input by key operation or mouse operation on the keyboard. To 21. In addition, the operation unit 23 may include a touch panel on the display screen of the display unit 24. In this case, the operation unit 23 outputs an instruction signal input via the touch panel to the control unit 21.

  The display unit 24 is configured by a monitor such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube), and displays an input instruction, data, or the like from the operation unit 23 in accordance with an instruction of a display signal input from the control unit 21. To do.

  The communication unit 25 includes a LAN adapter, a modem, a TA (Terminal Adapter), and the like, and controls data transmission / reception with each device connected to the communication network NT.

[Configuration of diagnostic console 3]
The diagnostic console 3 acquires a radiographic image from the imaging console 2 and displays the acquired radiographic image or performs a quantitative analysis on the radiographic image and displays an analysis result to support a doctor's diagnosis. It is a device.
As shown in FIG. 1, the diagnostic console 3 includes a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, and a communication unit 35, and each unit is connected by a bus 36.

  The control unit 31 includes a CPU, a RAM, and the like. The CPU of the control unit 31 reads out the system program and various processing programs stored in the storage unit 32 in accordance with the operation of the operation unit 33, expands them in the RAM, and in accordance with the expanded programs, the imaging console 2 The received radiation image is displayed, or the received radiation image is subjected to quantitative analysis processing.

  The storage unit 32 is configured by a nonvolatile semiconductor memory, a hard disk, or the like. The storage unit 32 stores various programs including a program for the control unit 31 to execute quantitative analysis processing, parameters necessary for execution of processing by the program, or data such as processing results. These various programs are stored in the form of readable program codes, and the control unit 31 sequentially executes operations according to the program codes.

  In the storage unit 32, the captured radiographic image includes patient information (eg, patient ID, patient name, height, weight, age, sex, etc.), examination information (eg, examination ID, examination date, subject part ( Here, it is stored in association with the chest), distinction between still image shooting and moving image shooting, presence / absence of quantitative analysis, and the like.

  The operation unit 33 includes a keyboard having cursor keys, numeric input keys, various function keys, and the like, and a pointing device such as a mouse. The operation unit 33 receives an instruction signal input by a key operation or a mouse operation on the keyboard by the user. Output to the control unit 31. The operation unit 33 may include a touch panel on the display screen of the display unit 34, and in this case, an instruction signal input via the touch panel is output to the control unit 31.

  The display unit 34 is configured by a monitor such as an LCD or a CRT, and performs various displays according to instructions of a display signal input from the control unit 31.

  The communication unit 35 includes a LAN adapter, a modem, a TA, and the like, and controls data transmission / reception with each device connected to the communication network NT.

[Operation of Radiation Imaging System 100]
Next, the operation of the radiation imaging system 100 in the present embodiment will be described.
First, the photographing operation by the photographing apparatus 1 and the photographing console 2 will be described.
FIG. 3 shows a flowchart of the photographing control process A executed by the control unit 21 of the photographing console 2. The imaging control process A is executed in cooperation with the control unit 21 and a program stored in the storage unit 22.

  First, the photographing person operates the operation unit 23 of the photographing console 2 to select photographing order information (step S1).

  Next, it is determined whether to perform moving image shooting or still image shooting based on the selected shooting order information (step S2).

  When it is determined that movie shooting is to be performed (step S2; YES), the radiation irradiation conditions for movie shooting corresponding to the shooting order information are read from the storage unit 22 and set in the radiation irradiation control device 12, and the movie is shot. Image reading conditions for photographing are read from the storage unit 22 and set in the reading control device 14 (step S3). The shooting conditions set here are the same as the reference shooting conditions when a reference image for moving image shooting is shot with a reference shooting device.

  Here, an imaging operator such as an imaging engineer positions the subject M and the reference phantom between the radiation source 11 and the radiation detection unit 13 for positioning. The reference phantom is disposed at a predetermined position that does not overlap the subject M. In addition, the subject is instructed to breathe (breath holding, deep breathing, rest breathing, etc.). When preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  In addition, since the relative positional relationship between the radiation source 11 and the radiation detection unit 13 affects the dose, a predetermined positional relationship (relative positional relationship between the radiation source and the radiation detection unit when the reference image is acquired by the reference imaging apparatus). It is preferable to adjust the center position, the relative angle, the irradiation field, etc. of the radiation source 11 and the radiation detector 13 so as to match, or to correct the influence of the distance according to the square law of the distance.

  When a radiation irradiation instruction is input through the operation unit 23, a photographing start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and the subject M and the reference phantom are simultaneously photographed (step S4). That is, radiation is emitted from the radiation source 11 under the imaging conditions set in the radiation irradiation controller 12, and a plurality of frame images depicting the subject M and the reference phantom are acquired by the radiation detection unit 13. When a predetermined imaging time has elapsed, the control unit 21 outputs an instruction to end imaging to the radiation irradiation control device 12 and the reading control device 14, and the imaging operation is stopped. Frame images acquired by shooting are sequentially input to the shooting console 2, and information such as a number (frame number) indicating the shooting order is associated with each of a series of frame images acquired by moving image shooting in the RAM. Remembered.

  Next, various correction processes are performed on each frame image of the moving image acquired by photographing (step S5). In step S5, for example, gain correction, offset correction, afterimage correction, pixel defect correction, line defect correction, density unevenness correction due to the radiation heel effect, temperature dependency of the radiation detection unit 13 and changes with time are included. Examples include correction, correction of pixel linearity, scattered radiation correction, correction of the influence of an intermediate substance (such as a bed or a top plate) between the radiation source 11 and the radiation detection unit 13, correction of body movement, and the like. Note that some correction processing may be performed after the signal value correction processing in steps S8 and S10.

Next, it is determined whether or not quantitative analysis is performed (step S6). For example, it is determined whether to perform quantitative analysis based on the inspection information of the imaging order information selected in step S1.
When it is determined that the quantitative analysis is to be performed (step S6; YES), the signal value of the reference phantom region (that is, the reference phantom image) is stored in the storage unit 22 for each frame image of the moving image obtained by photographing. In order to correct the signal value of each frame image of the moving image shot in step S4 based on the comparison with the signal value of the corresponding frame image (the frame image having the same frame number) of the reference image for moving image shooting A correction table (correction data) is generated (step S7). In the present application, the correction table is a table for correcting the signal value of the image obtained by photographing so as to match the signal value of the image obtained when the same subject is photographed under the same photographing condition by the reference photographing device. is there. For example, the signal value of each step obtained by radiographing the reference phantom F with the reference imaging device is shown in FIG. 4A, and each of the signal values obtained by radiographing the reference phantom F with the imaging device 1 is shown in FIG. When the signal value of the step is FIG. 4B (or (c)), the slope of the signal value of the plurality of steps in FIG. 4B (or (c)) is shown in FIG. A table to be converted into a value gradient is generated as a correction table. Of course, the signal value in the middle can be corrected according to the conversion.
Then, based on the generated correction table, the signal value of each frame image of the moving image shot in step S4 is corrected (step S8), and the process proceeds to step S16.

  Here, in moving image shooting, the radiation target is continuously irradiated to acquire a plurality of frame images (for example, 300 images), so that the state of the tube target and filament changes during shooting due to the influence of heat and the like. As a result, a phenomenon occurs in which the dose and quality of radiation output change during imaging. Therefore, in the present embodiment, the signal value and contrast of the moving image acquired by the current shooting are changed to the change of the signal value and contrast of the moving image due to the change of the radiation dose and the radiation quality during moving image shooting with the reference shooting device. In order to match, a reference image for moving image shooting that represents the signal value of the reference phantom area in each frame image obtained by moving the reference phantom with the reference shooting condition using the reference shooting device is prepared in advance. The signal value of the reference phantom area obtained by the current moving image shooting is compared with the signal value of the corresponding frame image of the reference image, and a correction table is generated based on the difference. Then, for each frame image of the moving image, the signal value is corrected based on the generated correction table. Therefore, the signal value and contrast of each frame image of the captured moving image can be adjusted to the change of the signal value and contrast due to the change of the dose and the radiation quality during the moving image shooting of the reference shooting device. It is possible to suppress variations in signal values and contrast of moving images.

  In the present embodiment, the signal value of the reference phantom area of each frame image obtained by moving image shooting is compared with the signal value of the corresponding frame image of the reference image for moving image shooting stored in the storage unit 22. In this example, the correction table of each frame image of the captured moving image is generated as an example. However, the signal value of the moving image corrected with respect to the signal value causing a problem in quantitative analysis or the change in contrast is explained. If the change in contrast is small, there is no problem even if the same correction table is used. Therefore, the correction table may be generated not for all frame images but for each number of sheets (for example, every 10 frames, every 50 frames, etc.) whose signal value and contrast change to such a degree that the analysis result is significantly affected. Good. In this case, reference images for moving image shooting may be stored in correspondence with the number of correction tables to be generated. For example, when the same correction table is used for 1 to 10 frames, the correction table is generated using the signal value of the reference phantom area of the first frame image and the signal value of the first frame image of the reference image. Then, it is possible to correct up to 1 to 10 frames using this correction table. Alternatively, a correction table is generated using the signal value of the reference phantom area of the fifth frame image in the middle and the signal value of the fifth frame image of the reference image, and 1 to 10 frames are generated using this correction table. May be corrected. Alternatively, a correction table is generated using the average value of the signal values of the reference phantom area of 1 to 10 frames and the average value of the signal values of 1 to 10 frames of the reference image, and the correction table is used to generate 1 to 10 frames. May be corrected. As a result, the processing time required to create the correction table can be shortened compared to the case where the correction table is generated for each frame image.

  On the other hand, if it is determined in step S6 that quantitative analysis is not performed (step S6; NO), the signal value of the reference phantom area of the predetermined frame image obtained by shooting and the moving image shooting stored in the storage unit 22 are stored. Based on the comparison with the signal value of the corresponding frame image of the reference image for use, a correction table of signal values of the captured moving image (common correction table of all frame images) is generated (step S9). Then, based on the generated correction table, the signal value of each frame image of the moving image shot in step S4 is corrected (step S10), and the process proceeds to step S16.

  Here, the change in signal value and contrast during moving image shooting cannot be understood by merely observing a moving image with the naked eye. Therefore, when only a moving image is displayed for visual observation without performing quantitative analysis, one correction table is generated, and all frame images are corrected with one correction table. For example, based on the comparison between the signal value of the reference phantom area of the first frame image obtained by shooting and the signal value of the first frame image of the reference image for moving image shooting stored in the storage unit 22. Thus, a common correction table for all frame images of the captured moving image may be generated. In addition, if the signal near the center of breathing is important in the diagnosis because the breathing is not calm at the beginning or the end of the movie shooting, or the breathing state at the end, it was obtained by shooting, for example Based on the comparison between the signal value of the reference phantom area of the intermediate frame image and the signal value of the intermediate frame image of the reference image for moving image shooting stored in the storage unit 22, all of the captured moving images are recorded. A common correction table for frame images may be generated. Alternatively, the average value of the signal values of the reference phantom area of all the frame images of the moving image obtained by shooting and the average value of the signal values of all the frame images of the reference image for moving image shooting stored in the storage unit 22 Based on the comparison, a common correction table of signal values of each frame image of the captured moving image may be generated. As a result, the processing time required to create the correction table can be shortened compared to the case where the correction table is generated for each frame image. The common correction table for all frame images may be created at the factory at the time of shipment and stored in the storage unit 22 of the imaging console 2 in advance.

  On the other hand, when it is determined in step S2 that still image shooting is performed (step S2; NO), the radiation irradiation conditions for still image shooting corresponding to the shooting order information are read from the storage unit 22 and the radiation irradiation control device. The image reading condition for still image shooting is read from the storage unit 22 and set in the reading control device 14 (step S11). The shooting conditions set here are the same as the reference shooting conditions when a reference image for shooting a still image is shot with a reference shooting device.

  Here, an imaging operator such as an imaging engineer positions the subject M and the reference phantom between the radiation source 11 and the radiation detection unit 13 for positioning. The reference phantom is disposed at a predetermined position that does not overlap the subject M. In addition, the subject is instructed to breathe (hold). When preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input through the operation unit 23, a photographing start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and the subject M and the reference phantom are simultaneously photographed (step S12). That is, radiation is emitted from the radiation source 11 under the imaging conditions set in the radiation irradiation control device 12, and one still image is acquired by the radiation detection unit 13. The still image acquired by shooting is input to the shooting console 2 and stored in the RAM.

  Next, various correction processes are performed on the still image acquired by photographing (step S13). In step S13, various correction processes described in step S5 are performed. Note that some correction processing may be performed after the signal value correction processing in step S15.

  Next, the signal value of the captured still image based on the comparison between the signal value of the reference phantom area of the still image obtained by shooting and the signal value of the reference image for still image shooting stored in the storage unit 22 Is generated (step S14). Then, the signal value of the still image is corrected based on the generated correction table (step S15), and the process proceeds to step S16.

  In step S16, an identification ID for identifying an image into a frame image or a still image of a corrected moving image, patient information, examination information, radiation irradiation conditions, image reading conditions, and the imaging order in the case of moving images are shown. Information such as a number (frame number) is attached (for example, written in the header area of the image data in the DICOM format) and transmitted to the diagnostic console 3 by the communication unit 25, and the imaging control process A ends.

  In the diagnostic console 3, when a radiographic image (moving image or still image) is received from the imaging console 2, the received radiographic image is stored in the storage unit 32 in association with patient information or examination information. When a radiographic image is selected by the operation unit 33 and display is instructed, the selected radiographic image is read from the storage unit 32 and displayed on the display unit 35 by the control unit 31. When a radiographic image is selected by the operation unit 33 and quantitative analysis is instructed, the control unit 31 reads the selected radiographic image from the storage unit 32 and performs quantitative analysis, and the analysis result is displayed on the display unit. 35. Examples of quantitative analysis of a moving image of the chest include ventilation analysis and blood flow analysis described in Japanese Patent Application Laid-Open No. 2012-110451. Further, the analysis using the signal value, not the in-plane analysis such as the length and the angle, can be similarly applied to other analyses.

As described above, in the first embodiment, the control unit 21 of the photographing console 2 causes the photographing apparatus 1 to simultaneously shoot the subject M and the reference phantom, and the reference phantom region of a plurality of frame images of the obtained moving image. And the moving image acquired by the imaging device 1 based on the signal values of the plurality of frame images of the reference image acquired by shooting the moving image of the reference phantom with the reference imaging condition by the reference imaging device. A correction table for correcting the signal value of each frame image is generated to correct the signal value of each frame image of the moving image.
Therefore, the signal value and contrast of each frame image of the captured moving image can be adjusted to the change of the signal value and contrast due to the change of the dose and the radiation quality during the moving image shooting of the reference shooting device. It is possible to suppress variations in signal values and contrast of moving images. As a result, it is possible to suppress variations in analysis results obtained by quantitatively analyzing moving images, and to provide highly accurate analysis results.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described.
In the first embodiment, the example in which the reference phantom and the subject are photographed at the same time has been described. In the second embodiment, an example in which the reference phantom is photographed before or after the subject is photographed will be described.

Since the configuration of the second embodiment is the same as that described in the first embodiment, the description will be used and the operation of the second embodiment will be described below.
FIG. 5 shows a flowchart of the photographing control process B executed in the control unit 21 of the photographing console 2. The imaging control process B is executed in cooperation with the control unit 21 and a program stored in the storage unit 22.

  First, the photographing person operates the operation unit 23 of the photographing console 2 to select photographing order information (step S21).

  Next, it is determined whether to perform moving image shooting or still image shooting based on the selected shooting order information (step S22).

  When it is determined that movie shooting is to be performed (step S22; YES), the radiation irradiation conditions for movie shooting corresponding to the shooting order information are read from the storage unit 22 and set in the radiation irradiation control device 12, and the movie is also recorded. Image reading conditions for photographing are read from the storage unit 22 and set in the reading control device 14 (step S23). The shooting conditions set here are the same as the reference shooting conditions when a reference image for moving image shooting is shot with a reference shooting device.

  Here, a radiographer such as a radiographer arranges the reference phantom at a predetermined position between the radiation source 11 and the radiation detection unit 13 and operates the operation unit 23 to input a radiation irradiation instruction. In addition, since the relative positional relationship between the radiation source 11 and the radiation detection unit 13 affects the dose, a predetermined positional relationship (relative positional relationship between the radiation source and the radiation detection unit when the reference image is acquired by the reference imaging apparatus). It is preferable to adjust the center position, the relative angle, the irradiation field, etc. of the radiation source 11 and the radiation detector 13 so as to match, or to correct the influence of the distance according to the square law of the distance.

  When a radiation irradiation instruction is input through the operation unit 23, a photographing start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and moving image photographing of the reference phantom is performed (step S24). Frame images of the reference phantom image acquired by moving image shooting are sequentially input to the shooting console 2, and information such as a number (frame number) indicating the shooting order corresponds to each of a series of frame images acquired by moving image shooting. Attached and stored in RAM.

  When the imaging of the reference phantom is completed, the imaging operator places the subject M between the radiation source 11 and the radiation detection unit 13 and performs positioning. In addition, the subject is instructed to breathe (breath holding, deep breathing, rest breathing, etc.). When preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input through the operation unit 23, a shooting start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and moving image shooting of the subject M is performed (step S25). The frame image of the moving image of the subject M acquired by moving image shooting is sequentially input to the shooting console 2, and information such as a number (frame number) indicating the shooting order is displayed on each of the series of frame images acquired by moving image shooting. Are associated and stored in the RAM.

  Next, various correction processes are performed on the moving image of the reference phantom and the moving image of the subject M acquired by photographing (step S26). The processing in step S26 is the same as that described in step S5 in FIG.

Next, it is determined whether or not to perform quantitative analysis (step S27). For example, it is determined whether or not to perform quantitative analysis based on the inspection information of the imaging order information selected in step S21.
If it is determined that the quantitative analysis is to be performed (step S27; YES), the signal value of each frame image of the reference phantom image and the corresponding frame image of the reference image for moving image shooting stored in the storage unit 22 (with the frame number). Based on the comparison with the signal value of the same frame image), a correction table for the signal value of each frame image of the captured moving image of the subject M is generated (step S28).
Then, the signal value of each frame image of the moving image of the subject M is corrected based on the generated correction table (step S29), and the process proceeds to step S38.
Since the process of step S28-S29 and its effect are the same as that of what was demonstrated by step S7-S8 of FIG. 3, description is used.

On the other hand, when it is determined in step S27 that the quantitative analysis is not performed (step S27; NO), the signal value of a predetermined frame image of the reference phantom image and the reference image for moving image shooting stored in the storage unit 22 are stored. Based on the comparison with the signal value of the corresponding frame image, a correction table (common correction table for all frame images) of the signal value of the captured moving image of the subject M is generated (step S30). Based on the generated correction table, the signal value of each frame image of the moving image of the subject M is corrected (step S31), and the process proceeds to step S38.
Since the process of step S30-S31 and its effect are the same as that of what was demonstrated by step S9-S10 of FIG. 3, description is used.

  On the other hand, if it is determined in step S22 that still image shooting is performed (step S22; NO), the radiation irradiation conditions for still image shooting corresponding to the shooting order information are read from the storage unit 22 and the radiation irradiation control device. The image reading condition for still image shooting is read from the storage unit 22 and set in the reading control device 14 (step S32). The shooting conditions set here are the same as the reference shooting conditions when a reference image for shooting a still image is shot with a reference shooting device.

  Here, a radiographer such as a radiographer places a reference phantom between the radiation source 11 and the radiation detection unit 13 and operates the operation unit 23 to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input by the operation unit 23, a photographing start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and a still image of the reference phantom is captured (step S33). The reference phantom image (still image) acquired by shooting is input to the shooting console 2 and stored in the RAM.

  When the imaging of the reference phantom is completed, the imaging operator places the subject M between the radiation source 11 and the radiation detection unit 13 and performs positioning. In addition, the subject is instructed to breathe (hold). When preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input through the operation unit 23, a photographing start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and still image photographing of the subject M is performed (step S34). Still images acquired by still image shooting are sequentially input to the shooting console 2 and stored in the RAM.

  Next, various correction processes are performed on the still image of the reference phantom and the still image of the subject M acquired by shooting (step S35). In step S35, various correction processes described in step S5 in FIG. 3 are performed.

  Next, based on a comparison between the signal value of the reference phantom image (still image) and the signal value of the reference image for still image shooting stored in the storage unit 22, the signal value of the still image of the photographed subject M is calculated. A correction table is generated (step S36). Then, the signal value of the still image of the subject M is corrected based on the generated correction table (step S37), and the process proceeds to step S38.

  In step S38, the identification ID for identifying the image in each frame image or still image of the corrected moving image, the patient information, the examination information, the radiation irradiation condition, the image reading condition, and the imaging order in the case of the moving image are set. Information such as a number (frame number) shown is attached (for example, written in the header area of the image data in the DICOM format) and transmitted to the diagnostic console 3 by the communication unit 25 (step S38), and the imaging control process B ends. To do.

  Since the process in the diagnostic console 3 is the same as that described in the first embodiment, the description is cited.

  In FIG. 5, the subject M is photographed after photographing the reference phantom under the same photographing conditions as those at the time of photographing the subject. However, it is also possible to photograph the reference phantom under the same photographing conditions after photographing the subject M. Good.

As described above, in the second embodiment, the control unit 21 of the photographing console 2 causes the photographing apparatus 1 to photograph the reference phantom before or after photographing the subject M as a moving image, and a plurality of reference phantom images obtained. Based on the signal value of the frame image and a plurality of frame images of the reference image acquired by shooting the moving image of the reference phantom with the reference shooting device under the reference shooting conditions, the moving image acquired by the shooting device 1 A correction table for correcting the signal value of each frame image is generated to correct the signal value of each frame image of the moving image.
Therefore, the signal value and contrast of each frame image of the captured moving image can be adjusted to the change of the signal value and contrast due to the change of the dose and the radiation quality during the moving image shooting of the reference shooting device. It is possible to suppress variations in signal values and contrast of moving images. As a result, it is possible to suppress variations in analysis results obtained by quantitatively analyzing moving images, and to provide highly accurate analysis results.

<Third Embodiment>
Hereinafter, a third embodiment of the present invention will be described.
In the third embodiment, an example in which a correction table is generated in advance prior to photographing of the subject M will be described.

In the third embodiment, the storage unit 22 stores signal values obtained when a reference phantom is captured in a still image under a plurality of still image capturing conditions (reference capturing conditions) set in a reference capturing device. The reference image for the still image to be represented, and the signal value in each frame image when the reference phantom is movie-recorded under a plurality of movie shooting conditions (reference shooting conditions) predetermined in the reference imaging device. A plurality of moving image reference images to be represented are stored.
Since the configuration of the other third embodiment is the same as that described in the first embodiment, the description will be used and the operation of the third embodiment will be described below.

  In the third embodiment, the correction table generation process shown in FIG. 6 is executed in advance, and correction tables corresponding to a plurality of shooting conditions are generated and stored in the storage unit 22. When the subject M is shot, shooting control processing C shown in FIG. 7 is executed, and each frame image and still image signal value of the moving image of the subject M obtained by shooting is corrected based on a correction table corresponding to the shooting conditions. Is done.

First, correction table generation processing will be described with reference to FIG. The correction table generation process is executed in cooperation with the control unit 21 and a program stored in the storage unit 22.
In the present embodiment, it is assumed that the reference phantom is previously arranged at a predetermined position between the radiation source 11 and the radiation detection unit 13. In addition, since the relative positional relationship between the radiation source 11 and the radiation detection unit 13 affects the dose, a predetermined positional relationship (relative positional relationship between the radiation source and the radiation detection unit when the reference image is acquired by the reference imaging apparatus). It is preferable to adjust the center position, the relative angle, the irradiation field, etc. of the radiation source 11 and the radiation detector 13 so as to match, or to correct the influence of the distance according to the square law of the distance.

  In the correction table generation processing, first, among the plurality of radiation irradiation conditions for moving image shooting stored in the storage unit 22, one radiation irradiation condition is read from the storage unit 22 and set in the radiation irradiation control device 12. At the same time, the corresponding image reading conditions are read from the storage unit 22 and set in the reading control device 14 (step S41).

  Next, a shooting start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and moving image shooting of the reference phantom is performed (step S42). Frame images acquired by moving image shooting are sequentially input to the shooting console 2, and each of the frame images of a series of reference phantom images acquired by moving image shooting has a shooting condition and a number (frame number) indicating the shooting order. Information is associated and stored in the RAM.

Next, the signal value of each frame image of the reference phantom image obtained by shooting and the corresponding frame image (frame) of the reference image obtained by shooting the reference phantom under the same shooting conditions stored in the storage unit 22. Based on the comparison with the signal value of the frame image having the same number), a correction table of the signal value of each frame image of the moving image photographed by the photographing apparatus 1 is generated (step S43). The processing in step S43 is the same as that described in step S7 in FIG. In addition, it is preferable to perform various correction processes described in step S5 of FIG. 3 on each frame image of the reference phantom image.
Then, the generated correction table is stored in the storage unit 22 in association with the shooting conditions (step S44).

  Until the moving image shooting of the reference phantom under all the predetermined shooting conditions and the generation of the correction table are completed, the processing of steps S41 to S44 is repeatedly executed while changing the shooting conditions, and the reference phantom under all the shooting conditions. When the moving image shooting and generation of the correction table are completed (step S45; YES), the process proceeds to step S46.

  In step S <b> 46, first, one radiation irradiation condition among the plurality of radiation irradiation conditions for still image shooting stored in the storage unit 22 is read from the storage unit 22 and set in the radiation irradiation control device 12. At the same time, the corresponding image reading conditions are read from the storage unit 22 and set in the reading control device 14 (step S46).

  Next, an imaging start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and still image shooting of the reference phantom is performed (step S47). A reference phantom image (still image) acquired by still image shooting is input to the shooting console 2 and stored in the RAM.

Next, the signal value of the reference phantom image (still image) obtained by shooting and the still image shooting obtained by shooting the reference phantom under the same shooting conditions with the reference shooting device stored in the storage unit 22. Based on the comparison with the signal value of the reference image for use, a correction table for the signal value of the still image photographed by the photographing apparatus 1 is generated (step S48). In addition, it is preferable to perform various correction processes described in step S5 of FIG. 3 on each frame image of the reference phantom image.
Then, the generated correction table is stored in the storage unit 22 in association with the shooting conditions (step S49).

  Until the still image shooting of the reference phantom under all the predetermined shooting conditions and the generation of the correction table are completed, the processing of steps S46 to S49 is repeatedly executed while changing the shooting conditions, and the reference phantom under all the shooting conditions. When the still image shooting and the generation of the correction table are completed (step S50; YES), the correction table generation process ends.

  Next, the imaging control process C executed in the third embodiment will be described with reference to FIG. The photographing control process C is executed in cooperation with the control unit 21 and a program stored in the storage unit 22.

  First, the photographing person operates the operation unit 23 of the photographing console 2 to select photographing order information (step S61).

  Next, it is determined whether to perform moving image shooting or still image shooting based on the selected shooting order information (step S62).

  When it is determined that movie shooting is to be performed (step S62; YES), a plurality of movie shooting conditions stored in the storage unit 22 are displayed on the display unit 24 and selected from the operation unit 23 by the photographer. The imaging conditions are set in the radiation irradiation control device 12 and the reading control device 14 (step S63).

  Here, the imaging operator places the subject M between the radiation source 11 and the radiation detection unit 13 to perform positioning. In addition, the subject is instructed to breathe (breath holding, deep breathing, rest breathing, etc.). When preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input through the operation unit 23, a shooting start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and moving image shooting of the subject M is performed (step S64). Frame images acquired by moving image shooting are sequentially input to the shooting console 2, and a series of frame images acquired by moving image shooting is associated with information such as numbers (frame numbers) indicating the shooting order in the RAM. Is remembered.

  Next, various correction processes are performed on the moving image of the subject M acquired by photographing (step S65). The processing in step S65 is the same as that described in step S5 in FIG.

Next, a correction table (correction table for each frame image) corresponding to the shooting conditions used for moving image shooting is read from the storage unit 22, and each frame image of the moving image of the subject M is read based on the read correction table. Is corrected (step S66), and the process proceeds to step S71.
Since the process and effect of step S66 are the same as what was demonstrated by step S8 of FIG. 3, description is used.

  On the other hand, if it is determined in step S62 that still image shooting is to be performed (step S62; NO), a plurality of still image shooting conditions stored in the storage unit 22 are displayed on the display unit 24, and shooting is performed. The imaging conditions selected by the operator from the operation unit 23 are set in the radiation irradiation control device 12 and the reading control device 14 (step S67).

  Here, the imaging operator places the subject M between the radiation source 11 and the radiation detection unit 13 to perform positioning. In addition, the subject is instructed to breathe (hold). When preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input through the operation unit 23, a photographing start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and a still image of the subject M is captured (step S68). An image acquired by still image shooting is input to the shooting console 2 and stored in the RAM.

  Next, various correction processes are performed on the still image of the subject M acquired by photographing (step S69). The processing in step S69 is the same as that described in step S5 in FIG.

Next, a correction table corresponding to the shooting conditions used for still image shooting is read from the storage unit 22, and the signal value of the still image of the subject M is corrected based on the read correction table (step S70). The process proceeds to step S71.
Since the process and effect of step S70 are the same as what was demonstrated by step S8 of FIG. 3, description is used.

  In step S71, the identification ID for identifying the image in each frame image or still image of the corrected moving image, the patient information, the examination information, the radiation irradiation condition, the image reading condition, and the imaging order in the case of the moving image are set. Information such as a number (frame number) shown is attached (for example, written in the header area of the image data in the DICOM format) and transmitted to the diagnostic console 3 by the communication unit 25 (step S71), and the imaging control process C ends. To do.

  Since the process in the diagnostic console 3 is the same as that described in the first embodiment, the description is cited.

  In step S43 of the correction table generation process, in addition to the correction table for each frame image, a common correction table for all frame images corresponding to the case where quantitative analysis is not performed is also generated and associated with the shooting conditions. It may be stored in the storage unit 22. Then, it is determined whether or not quantitative analysis is to be performed during moving image shooting of the subject M, and if not, using a correction table common to all frame images corresponding to the shooting conditions used for moving image shooting from the storage unit 22. The signal value of each frame image of the moving image of the subject M may be corrected.

  The third embodiment is effective, for example, when shooting is performed under different shooting conditions depending on the physique of the subject M and the like. In the first and second embodiments as well, reference data acquired by shooting a reference phantom with a plurality of shooting conditions set in advance by a reference shooting apparatus is stored in association with the shooting conditions. If the correction table is generated using the reference image that is stored in the unit 22 and that corresponds to the shooting conditions used in actual shooting, the shooting conditions can be changed according to the physique of the subject M and the like.

As described above, in the third embodiment, the control unit 21 of the photographing console 2 causes the photographing apparatus 1 to shoot a video of the reference phantom under a plurality of photographing conditions, and each of the obtained plurality of reference phantom images. Based on the signal value of the frame image and the signal value of the plurality of frame images of the reference image taken with the same shooting conditions as when the reference phantom image was shot with the reference shooting device, each of the shooting conditions A correction table is generated and stored in the storage unit 22. Then, when the subject M is captured as a moving image by the photographing apparatus 1, the signal value of each frame image of the moving image photographed based on the correction table corresponding to the photographing condition when the subject M is photographed is corrected.
Therefore, the signal value and contrast of each frame image of the captured moving image can be adjusted to the change of the signal value and contrast due to the change of the dose and the radiation quality during the moving image shooting of the reference shooting device. It is possible to suppress variations in signal values and contrast of moving images. As a result, it is possible to suppress variations in analysis results obtained by quantitatively analyzing moving images, and to provide highly accurate analysis results.

  In the third embodiment, a correction table corresponding to a plurality of shooting conditions is created. However, a correction table corresponding to one reference shooting condition is generated in advance prior to shooting and stored in the storage unit 22. It is good also to memorize in. Then, when a moving image is shot, the signal value of each frame image of the moving image acquired by shooting may be corrected based on the correction table stored in the storage unit 22.

<Fourth Embodiment>
The fourth embodiment of the present invention will be described below.
In the fourth embodiment, a signal value similar to a moving image signal value (specifically, a reference phantom signal value or contrast) obtained when a moving image is shot under a reference shooting condition in a reference shooting apparatus is used. An example in which imaging conditions that can be obtained are obtained by adjusting the imaging apparatus 1 in advance will be described.

  Since the configuration of the fourth embodiment is the same as that described in the first embodiment, the description will be used and the operation of the fourth embodiment will be described below.

FIG. 8 shows a flowchart of the photographing condition adjustment process executed in the control unit 21 of the photographing console 2. The photographing condition adjustment process is executed in cooperation with the control unit 21 and a program stored in the storage unit 22.
In the present embodiment, it is assumed that the reference phantom is previously arranged at a predetermined position between the radiation source 11 and the radiation detection unit 13. In addition, since the relative positional relationship between the radiation source 11 and the radiation detection unit 13 affects the dose, a predetermined positional relationship (relative positional relationship between the radiation source and the radiation detection unit when the reference image is acquired by the reference imaging apparatus). It is preferable to adjust the center position, the relative angle, the irradiation field, etc. of the radiation source 11 and the radiation detector 13 so as to match, or to correct the influence of the distance according to the square law of the distance.

  First, the radiation irradiation conditions set by the operation unit 23 are set in the radiation irradiation control device 12, and the image reading conditions are set in the reading control device 14 (step S81).

  Next, an imaging start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and moving image shooting of the reference phantom is performed (step S82). Frame images acquired by moving image shooting are sequentially input to the shooting console 2, and information such as numbers (frame numbers) indicating the shooting order corresponds to a series of frame images of the reference phantom image acquired by moving image shooting. Attached and stored in RAM.

  Next, the signal value of a predetermined frame image in the reference phantom image obtained by shooting and the signal value of the corresponding frame image (frame image having the same frame number) of the reference image for moving image shooting stored in the storage unit 22 Are compared (step S83).

  In step S83, for example, the signal value of the first frame image of the reference phantom image obtained by moving image shooting and the signal of the first frame image of the reference image for moving image shooting stored in the storage unit 22 are stored. Compare the value. In addition, if the signal near the center of breathing is important in the diagnosis because the breathing is not calm at the beginning or the end of the movie shooting, or the breathing state is at the end, it can be obtained by, for example, movie shooting. Alternatively, the signal value of the intermediate frame image of the reference phantom image may be compared with the signal value of the intermediate frame image of the moving image shooting reference image stored in the storage unit 22. Alternatively, the average value of the signal value of each frame image of the reference phantom image obtained by moving image shooting is compared with the average value of the signal value of each frame image of the reference image for moving image shooting stored in the storage unit 22. It is good as well.

  As a result of the comparison, when it is determined that the signal value of the reference phantom image does not match the signal value of the reference image for moving image shooting (step S84; NO), the process returns to step S81, and the processes of steps S81 to S84 are performed. Is repeatedly executed. Here, if the difference between the signal value of the reference phantom image and the signal value of the reference image (difference between the signal values in the same step (thickness) region of the reference phantom) is within a predetermined range, it is one. It is judged that it has done.

  When it is determined that the signal value of the reference phantom image matches the signal value of the reference image (step S84; YES), the shooting condition set in step S81 is determined as the shooting condition when shooting the moving image of the subject M. Is stored in the storage unit 22 (step S85), and the photographing condition adjustment processing is terminated.

  For example, the reference phantom image obtained when the reference phantom is captured by the image pickup apparatus 1 under certain shooting conditions (for example, tube voltage = 95 kV, tube current = 60 mA, shooting time = 5.3 msec, SID = 2 m). A reference image obtained by shooting a moving image with a reference phantom in a reference phantom with a reference phantom in a reference photographic condition (for example, tube voltage = 100 kV, tube current = 53 mA, shooting time = 5.3 msec, SID = 2 m). When the signal value is equal to the signal value, the shooting condition for moving image shooting is determined as (tube voltage = 95 kV, tube current = 60 mA, shooting time = 5.3 msec, SID = 2 m) and stored in the storage unit 22.

  When performing quantitative analysis, the control unit 21 reads out the shooting conditions adjusted by the shooting condition adjustment process from the storage unit 22 and performs moving image shooting under the read shooting conditions.

Note that the shooting condition adjustment processing shown in FIG. 8 describes the case of adjusting shooting conditions during movie shooting, but it is obtained by shooting a still image with the reference phantom using the reference shooting conditions in the reference shooting device. Alternatively, the reference image for still image shooting may be stored in the storage unit 22, and the shooting conditions used for still image shooting may be adjusted by replacing the moving image shooting in the shooting condition adjustment process with still image shooting.
Further, the signal value correction processing described in the first to third embodiments may be performed after adjusting the imaging conditions.

  A moving image (still image) obtained by imaging is associated with patient information, examination information, imaging order, etc., and transmitted to the diagnostic console 3 by the communication unit 25. Since the process in the diagnostic console 3 is the same as that described in the first embodiment, the description is cited.

In the fourth embodiment, a moving image is taken of the reference phantom while adjusting the shooting conditions in the shooting device 1, and the signal value of the obtained reference phantom image is obtained by shooting with the reference shooting device under the reference shooting conditions. When the signal value of the reference image matches, the shooting condition at the time of reference phantom shooting in the shooting device 1 is stored in the storage unit 22 as shooting conditions for moving image shooting. During moving image shooting, moving image shooting is performed using shooting conditions for moving image shooting stored in the storage unit 22.
Therefore, the shooting conditions are adjusted so that the signal value of the moving image obtained by moving image shooting matches the signal value of the moving image shot under the reference shooting conditions by the reference shooting device. It is possible to suppress variations in the signal value and contrast of a radiographic moving image. As a result, it is possible to suppress variations in analysis results obtained by quantitatively analyzing moving images, and to provide highly accurate analysis results.

  Note that it is preferable to store the imaging conditions used for imaging the patient in association with the captured images, and to perform imaging under the same imaging conditions when imaging the same patient. Thereby, stable follow-up observation becomes possible.

As described above, according to the radiation imaging system 100 in the first to third embodiments, the reference phantom is captured with the reference imaging device in the storage unit 22 of the imaging console 2 using the reference phantom as the reference imaging condition. The control unit 21 stores a plurality of frame images of the reference phantom image obtained by taking a moving image of the reference phantom with the photographing apparatus 1 and the reference stored in the storage unit 22. Based on a plurality of frame images of the image, the signal value of each frame image of the moving image acquired by the imaging device 1 is obtained when the same subject is taken with the reference imaging condition by the reference imaging device. A plurality of correction tables for correction are generated, and a signal of each frame image of the moving image acquired by the photographing apparatus 1 using the generated correction table It is corrected.
Therefore, the signal value and contrast of each frame image of the captured moving image can be adjusted to the change of the signal value and contrast due to the change of the dose and the radiation quality during the moving image shooting of the reference shooting device. It is possible to suppress variations in signal values and contrast of moving images. As a result, it is possible to suppress variations in analysis results obtained by quantitatively analyzing moving images, and to provide highly accurate analysis results.

  For example, by generating one correction table for each frame image of the captured moving image, the signal value of each frame image of the moving image acquired by the image capturing device 1 is used as a reference for the same subject. It is possible to accurately correct the signal value obtained when moving image shooting is performed under shooting conditions.

  Further, for example, by generating one correction table for each of a plurality of frame images that are not all of the captured moving images, the processing time required for generating the correction table can be shortened.

  Further, for example, when a quantitative analysis is performed on a captured moving image, a signal of each frame image of the moving image using a plurality of correction tables generated for each frame image of the moving image or for each of a plurality of frame images. When the value is corrected and the moving image is not subjected to quantitative analysis, the signal value of each frame image of the moving image is corrected by using one correction table common to all the frame images of the moving image. The processing time required for generating the correction table when no analysis is performed can be shortened.

  Further, a correction table for correcting the signal value of each frame image of a moving image acquired when moving image shooting is performed by the shooting apparatus 1 and a still image signal acquired when still image shooting is performed. By using different correction tables for correcting the values, it is possible to perform corrections suitable for both moving image shooting and still image shooting.

In addition, the description content in the said embodiment is a suitable example of this invention, and is not limited to this.
For example, in the above embodiment, the case where the present invention is applied to a moving image with the chest as a subject has been described as an example. However, for example, the present invention is applied to a moving image with another portion such as a joint of a limb as a subject. It is good to do.

  For example, in the above description, an example in which a hard disk, a semiconductor nonvolatile memory, or the like is used as a computer-readable medium of the program according to the present invention is disclosed, but the present invention is not limited to this example. As another computer-readable medium, a portable recording medium such as a CD-ROM can be applied. A carrier wave is also applied as a medium for providing program data according to the present invention via a communication line.

  In addition, the detailed configuration and detailed operation of each apparatus constituting the radiation imaging system can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 Radiation imaging system 1 Imaging device 11 Radiation source 12 Radiation irradiation control device 13 Radiation detection part 14 Reading control device 2 Imaging console 21 Control part 22 Storage part 23 Operation part 24 Display part 25 Communication part 26 Bus 3 Diagnosis console 31 Control Unit 32 Storage unit 33 Operation unit 34 Display unit 35 Communication unit 36 Bus

Claims (10)

A radiation imaging system comprising imaging means for acquiring a moving image by irradiating a subject with radiation and capturing a moving image,
Storage means for storing a reference image obtained by shooting a moving image under a reference phantom with a reference shooting condition by a reference shooting device;
Each frame of the moving image obtained by the photographing means using a plurality of frame images of the reference phantom image obtained by taking a moving image of the reference phantom by the photographing means and a plurality of frame images of the reference image. Generating means for generating a plurality of correction data for correcting the signal value of the image;
Correction means for correcting the signal value of each frame image of the moving image using the correction data generated by the generation means;
A radiography system comprising:   The photographing means simultaneously shoots the subject and the reference phantom as moving images, and generates the correction data in the generation means using the obtained plurality of frame images of the reference phantom image and the plurality of frame images of the reference image. The radiation imaging system according to claim 1, further comprising a control unit that controls the radiation imaging system.   Before or after taking the moving image of the subject by the shooting means, the reference phantom is taken as a moving picture, and the generation means is used by using a plurality of frame images of the reference phantom image and a plurality of frame images of the reference image obtained. The radiation imaging system according to claim 1, further comprising a control unit that generates the correction data. The storage means stores a plurality of reference images obtained by shooting the reference phantom with a plurality of shooting conditions with the reference shooting device,
The photographing means is used to shoot the reference phantom under the plurality of photographing conditions, and the plurality of frame images of the obtained plurality of reference phantom images and the same photographing conditions as when the reference phantom image is photographed. Using the plurality of frame images of the reference image taken as a moving image, the generation unit generates the correction data for each of a plurality of shooting conditions and stores the correction data in the storage unit, and the shooting unit captures the subject as a moving image. 2. The control unit according to claim 1, further comprising a control unit configured to correct a signal value of each frame image of the moving image based on the correction data corresponding to a shooting condition when the subject is shot by the correction unit. Radiography system.   The radiation imaging system according to claim 1, wherein the generation unit generates one correction data for each frame image of the moving image.   The radiation imaging system according to claim 1, wherein the generation unit generates one correction data for each of a plurality of frame images that are not all of the moving images.   The radiation imaging system according to claim 1, further comprising quantitative analysis means for performing quantitative analysis on the moving image whose signal value has been corrected by the correction means.   When performing a quantitative analysis on the moving image, the correcting unit uses the plurality of correction data generated by the generating unit for each frame image of the moving image or for each of a plurality of frame images. When the signal value of each frame image is corrected and the moving image is not subjected to quantitative analysis, the moving image is generated using a single correction data common to all the frame images of the moving image generated by the generating unit. The radiation imaging system according to claim 7, wherein the signal value of each frame image of the image is corrected. The photographing means can further acquire a still image by irradiating a subject with radiation and photographing a still image,
The generation means includes first generation means for generating correction data for correcting a signal value of each frame image of the moving image acquired when moving image shooting is performed by the shooting means; and the shooting means The second generation means for generating correction data for correcting the signal value of the still image acquired when still image shooting is performed by:
When the moving image is shot by the shooting unit, the correction unit corrects the signal value of each frame image of the moving image using the correction data generated by the first generation unit, and 9. The signal value of the still image is corrected using the correction data generated by the second generation unit when still image shooting is performed by the imaging unit. The radiation imaging system described. A console for correcting a moving image obtained by shooting a moving image by irradiating a subject with radiation,
Storage means for storing a reference image obtained by shooting a moving image under a reference phantom with a reference shooting condition by a reference shooting device;
Each frame of the moving image obtained by the photographing means using a plurality of frame images of the reference phantom image obtained by taking a moving image of the reference phantom by the photographing means and a plurality of frame images of the reference image. Generating means for generating a plurality of correction data for correcting the signal value of the image;
Correction means for correcting the signal value of each frame image of the moving image using the correction data generated by the generation means;
Console with.

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