Imaging control device, program, and radiation imaging system

Abstract

To set more suitable imaging conditions in kymography.SOLUTION: A console 2 for imaging (imaging control device) is an imaging control device for controlling kymography for imaging a dynamic state of a subject by irradiating a subject with a radiation ray and acquiring a plurality of frame images includes: a first acquisition unit (control unit 21) for acquiring first order information including at least one of information on presence or absence of a dynamic state analysis executed for a dynamic image acquired by the kymography and information on dynamic state analysis items; a first determination unit (control unit 21) for determining a first imaging condition and a target image quality on the basis of the first order information acquired by the first acquisition unit; and a second determination unit (control unit 21) for determining a second imaging condition for achieving the target image quality determined by the first determination unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an imaging control device, a program, and a radiation imaging system. [Background technology]

[0002] In recent years, radiography has made it possible to obtain images (called dynamic images) that capture the movement of a target area in a living body (the area that is the subject of examination and diagnosis) by taking continuous images (dynamic images) over an extremely short period of time. In order to capture dynamic images suitable for diagnosis and analysis, it is necessary to appropriately set imaging conditions such as the tube voltage of the radiation source and the tube current time product.

[0003] In this regard, Patent Document 1 describes a radiographic image processing device that adjusts image feature amounts that are correlated with the radiographic image capturing conditions input from a radiographic image capturing device, and then corrects the radiographic image capturing conditions for the next capture in accordance with the adjustment of the image feature amounts. Furthermore, Patent Document 2 describes an imaging condition output device that outputs imaging conditions by inputting subject information into a trained model for outputting imaging conditions for cone beam CT images used for subject alignment. Patent document 3 also describes a dynamic image capture control device that determines the frame rate to be used for dynamic capture based on an upper frame rate at which an index value indicating the image quality of a frame image obtained at the beginning of dynamic capture is equal to or less than a predetermined reference value, and a minimum lower frame rate required to diagnose the dynamics of the captured area. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-172362 [Patent Document 2] Patent Publication No. 2021-112471 [Patent Document 3] Patent No. 5195907 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional dynamic radiography, the target image quality of dynamic images set is constant regardless of whether or not dynamic analysis is performed on the dynamic images and the dynamic analysis items. In this case, depending on the dynamic analysis items, the image quality of the acquired dynamic images is low, resulting in low analysis accuracy. In addition, depending on the dynamic analysis items, the image quality is excessively high, resulting in unnecessarily high radiation exposure for the patient. The above problems are not solved by Patent Documents 1 to 3.

[0006] An object of the present invention is to provide an imaging control device, a program, and a radiation imaging system that can set imaging conditions more suitable for dynamic imaging. [Means for solving the problem]

[0007] In order to solve the above problem, the photography control device of the invention described in claim 1 comprises: An imaging control device that controls dynamic imaging for imaging dynamics of a subject by irradiating the subject with radiation and acquiring a plurality of frame images, a first acquisition unit that acquires first order information including at least one of information on whether or not a dynamic analysis is to be performed on the dynamic image acquired by the dynamic imaging and information on dynamic analysis items; a first determination unit that determines a first photographing condition and a target image quality based on the first order information acquired by the first acquisition unit; a second determination unit that determines a second photographing condition for achieving the target image quality determined by the first determination unit; a second acquisition unit that acquires second order information, which is information related to the imaging region; Equipped with 、 The second determination unit determines the second photographing condition based on the target image quality and the second order information. do.

[0008] The invention described in claim 2 is the imaging control device described in claim 1, The first order information includes instruction information regarding the breathing of the subject during the dynamic imaging.

[0009] The invention described in claim 3 is the imaging control device described in claim 1 or 2, The first determination unit determines the first imaging condition based on a first table indicating a relationship between the first order information and the first imaging condition.

[0010] The invention described in claim 4 is the imaging control device according to any one of claims 1 to 3, The first imaging condition includes any one of the body position of the subject during the dynamic imaging, the distance between a radiation source and a radiation detection unit that generates an image according to the radiation irradiated from the radiation source, the frame rate during the dynamic imaging, and the imaging time for the dynamic imaging.

[0012] Also, claims 5 The invention described in claim Any one of 1 to 4 In the imaging control device described in The second order information includes the BMI of the subject.

[0013] Also, claims 6 The invention described in claim Any one of 1 to 5 In the imaging control device described in The second determination unit determines the second photographing condition based on a second table indicating a relationship between the target image quality, the second order information, and the second photographing condition.

[0014] Also, claims 7 The invention described in claim 1 from 6 In the imaging control device according to any one of the above items, The second imaging condition includes any one of a tube voltage, a tube current, and a radiation exposure time per frame image in a radiation source.

[0015] Also, claims 8 The invention described in claim 1 from7 In the imaging control device according to any one of the above items, the first determination unit determines, based on the first order information, a target signal value of a region of interest in the frame image or a target value of an index indicating image quality as the target image quality; The second determination unit determines the second photographing condition that can achieve the target signal value or a target value in the index indicating the image quality.

[0016] Also, claims 9 The invention described in claim 1 from 8 In the imaging control device according to any one of the above items, a calculation unit that calculates a total exposure dose in the dynamic radiography based on the first radiography condition determined by the first determination unit and the second radiography condition determined by the second determination unit; a determination unit that determines whether the total exposure dose calculated by the calculation unit is greater than a predetermined value; a notification control unit that issues an alert when the determination unit determines that the total exposure dose is greater than a predetermined value; and Equipped with.

[0017] Also, claims 10 The invention described in claim 9 In the imaging control device described in The display control unit is configured to display on a display unit a suggestion to reduce the frame rate in the dynamic imaging or to shorten the imaging time of the dynamic imaging when the judgment unit judges that the total exposure dose is greater than a predetermined value.

[0018] Also, claims 11 The program described in a computer of an imaging control device that controls dynamic imaging to capture dynamic images of a subject by irradiating the subject with radiation and acquiring a plurality of frame images; a first acquisition unit that acquires first order information including at least one of information on whether or not a dynamic analysis is to be performed on the dynamic image acquired by the dynamic imaging and information on the dynamic analysis items; a first determination unit that determines a first photographing condition and a target image quality based on the first order information acquired by the first acquisition unit; a second determination unit that determines a second photographing condition for achieving the target image quality determined by the first determination unit; a second acquisition unit that acquires second order information, which is information related to the imaging region; Function as 、 The second determination unit determines the second photographing condition based on the target image quality and the second order information. do.

[0019] Also, claims 12 The radiation imaging system described in Claim 1 from 10 an imaging control device according to any one of the preceding claims; an external device connected to the imaging control device and transmitting the first order information and the second order information; Equipped with. [Effects of the Invention]

[0020] According to the present invention, it is possible to set imaging conditions that are more suitable for dynamic imaging. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a diagram showing the main configuration of a radiation imaging system according to an embodiment of the present invention; [Figure 2] FIG. 10 is a diagram illustrating an example of a shooting condition table. [Figure 3A] FIG. 10 is a diagram showing the relationship between the S value and the BMI of a patient to be photographed. [Figure 3B] FIG. 10 is a diagram showing the relationship between the mAs value and the BMI of a subject patient. [Figure 4] 10 is a flowchart showing the flow of a photographing condition determination process. [Figure 5] FIG. 10 is a diagram showing an example of a shooting condition table according to a modified example. [Figure 6] 10 is a flowchart showing the flow of a modified example of a shooting condition determination process. [Figure 7] FIG. 10 is a diagram showing an example of an inspection screen. [Figure 8] FIG. 10 is a diagram showing an example of an inspection screen. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of an imaging control device, a program, and a radiation imaging system according to the present invention will be described with reference to FIGS. However, although the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, the technical scope of the present invention is not limited to the following embodiments and illustrated examples.

[0023] FIG. 1 is a diagram showing the overall configuration of a radiation imaging system 100 according to this embodiment. 1, the radiation imaging system 100 is configured such that an imaging device 1 and an imaging console 2, which is an imaging control device, are connected by a communication cable or the like, and the imaging console 2 and a diagnostic console 3 are connected via a communication network NT such as a LAN (Local Area Network). 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.

[0024] The radiation imaging system 100 is also connected to a host system 200 (for example, a Radiology Information System (RIS) or a Picture Archiving and Communication System (PACS)) via a communication network NT. The host system 200 transmits photographing order information, in which information necessary for photographing is set, to the photographing console 2 via the communication network NT. The photographing order information includes first order information (described later) and second order information (described later). The radiation imaging system 100 may also include an imaging table (not shown) (for imaging in an upright position, imaging in a supine position, imaging in a long length, etc.) for holding the radiation detection unit 13 (described later). The radiation imaging system 100 may be installed in an imaging room, or may be a medical cart (configured so that the imaging device 1 can be moved).

[0025] [Configuration of the imaging device 1] The imaging device 1 is an imaging means for imaging the dynamics of a living body, such as changes in the shape of the lungs expanding and contracting with breathing, and the beating of the heart. As shown in FIG. 1, the imaging device 1 includes a radiation source 11, a radiation irradiation control device 12, a radiation detection unit 13, and a reading control device .

[0026] Dynamic imaging here refers to the acquisition of images by radiography of a subject including a target area in a living organism (for example, the area around the lung field in the chest, the heart, etc.), and refers to the acquisition of multiple images by repeatedly irradiating the subject with pulsed radiation such as X-rays at predetermined time intervals (pulse irradiation) or by continuously irradiating the subject with low dose rate radiation without interruption (continuous irradiation). A series of images acquired by dynamic imaging is called a dynamic image. A dynamic image is composed of multiple images from one imaging session, and the images that make up a dynamic image are called frame images. In the following embodiment, a case where dynamic imaging is performed using pulse irradiation will be described as an example. Target areas for dynamic imaging include the lung field and surrounding areas of the chest (lung fields and diaphragm), the heart, pulmonary blood vessels, intercostal muscles, thorax, intestines and esophagus of the stomach, as well as various orthopedic areas and various tissues such as knees, elbows, neck, and spine.

[0027] 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) under 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 to perform radiation imaging based on imaging conditions input from the imaging console 2. The imaging conditions input from the imaging console 2 include, for example, imaging mode (still image capture, dynamic image capture), imaging position, the distance (SID) between the radiation source 11 and the radiation detection unit 13, pulse rate, imaging time which is the time required for one imaging session, pulse width (pulse time), pulse interval, number of imaging frames per imaging session, tube current value, tube voltage value, and additional filter type. The pulse rate is the number of radiation irradiations per second and corresponds to the frame rate described below. The pulse width is the radiation irradiation time per radiation irradiation. The pulse interval is the time from the start of one radiation irradiation to the start of the next radiation irradiation and corresponds to the frame interval described below.

[0028] The radiation detection unit 13 is composed of a semiconductor image sensor such as an FPD (Flat Panel Detector). The FPD has, for example, a glass substrate or the like, and a plurality of detection elements (pixels) are arranged in a matrix at predetermined positions on the substrate. The detection elements detect radiation emitted from the radiation source 11 and transmitted through at least the subject M according to its intensity, and convert the detected radiation into an electrical signal and store it. Each pixel is equipped with a switching unit such as a TFT (Thin Film Transistor). FPDs can be of an indirect conversion type, in which X-rays are converted into an electrical signal by a photoelectric conversion element via a scintillator, or a direct conversion type, in which X-rays are directly converted into an electrical signal, and either type may be used. The radiation detection unit 13 is disposed opposite the radiation source 11 with the subject M interposed therebetween.

[0029] The reading control device 14 is connected to the radiography console 2. The reading control device 14 controls the switching units of each pixel of the radiation detection unit 13 based on the image reading conditions input from the radiography console 2, switches the reading of the electrical signals accumulated in each pixel, and acquires image data by reading the electrical signals accumulated in the radiation detection unit 13. This image data is a frame image. The reading control device 14 then outputs the acquired frame image to the radiography console 2. The image reading conditions include, for example, the frame rate, frame interval, pixel size, image size (matrix size), etc. The frame rate is the number of frame images acquired per second and coincides with the pulse rate. The frame interval is the time from the start of acquisition of one frame image to the start of acquisition of the next frame image and coincides with the pulse interval.

[0030] The radiation irradiation control device 12 and the reading control device 14 are connected to each other and exchange synchronization signals with each other to synchronize the radiation irradiation operation and the image reading operation.

[0031] [Configuration of imaging console 2] The imaging console 2 outputs imaging conditions and image reading conditions to the imaging device 1 to control the radiographic imaging and radiographic image reading operations by the imaging device 1, and also displays dynamic images acquired by the imaging device 1 so that the imaging technician or other person performing the imaging can check the positioning and whether the images are suitable for diagnosis. As shown in FIG. 1, the radiography console 2 comprises 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 .

[0032] The control unit 21 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), etc. In response to an operation of the operation unit 23, the CPU of the control unit 21 reads out a system program and various processing programs stored in the storage unit 22 and loads them into the RAM, and executes various processes including an imaging condition determination process (to be described later) according to the loaded programs, thereby centrally controlling the operation of each unit of the imaging console 2 and the radiation irradiation operation and reading operation of the imaging device 1.

[0033] The control unit 21 also acquires first order information including at least one of information on whether or not a dynamic analysis is to be performed on the dynamic image acquired by dynamic imaging and information on the dynamic analysis items. Here, the control unit 21 functions as a first acquisition unit. Furthermore, the control unit 21 determines the first photographing condition and the target image quality based on the first order information acquired by the first acquisition unit 21. Here, the control unit 21 functions as a first determination unit. Furthermore, the control unit 21 determines second shooting conditions for achieving the target image quality determined by the first determination unit 21. Here, the control unit 21 functions as a second determination unit. The control unit 21 also acquires second order information, which is information relating to the imaging region, and functions as a second acquisition unit.

[0034] The storage unit 22 is configured by a non-volatile semiconductor memory, a hard disk, etc. The storage unit 22 stores various programs executed by the control unit 21, parameters required for executing processes by the programs, data such as processing results, etc. For example, the storage unit 22 stores a program for executing the shooting condition determination process shown in FIG. The various programs are stored in the form of readable program codes, and the control unit 21 sequentially executes operations in accordance with the program codes. The storage unit 22 also stores an imaging condition table (described later) including a first table and a second table.

[0035] The operation unit 23 is configured with a keyboard having cursor keys, numeric input keys, various function keys, etc., and a pointing device such as a mouse, and outputs instruction signals input by operating the keys on the keyboard or the mouse to the control unit 21. The operation unit 23 may also have a touch panel on the display screen of the display unit 24, and in this case, outputs instruction signals input via the touch panel to the control unit 21.

[0036] The display unit 24 is composed of a monitor such as an LCD (Liquid Crystal Display) or CRT (Cathode Ray Tube), and displays input instructions and data from the operation unit 23 according to instructions of a display signal input from the control unit 21.

[0037] The communication unit 25 includes a LAN adapter, a modem, a TA (Terminal Adapter), etc., and controls data transmission and reception between each device connected to the communication network NT.

[0038] [Explanation of the imaging condition table] Next, the photographing condition table stored in the storage unit 22 will be described. FIG. 2 shows an example of the imaging condition table.

[0039] The imaging condition table provides a breathing protocol (information instructing the subject (patient)'s breathing during dynamic imaging), imaging condition A (imaging position, SID, frame rate, imaging time) which is the first imaging condition, and target image quality, with the dynamic analysis item or the presence or absence of dynamic analysis being the first order information as a major classification. In other words, the imaging condition table (first table) shows the relationship between the first order information and the first imaging condition. The target image quality is the target signal value in the region of interest (ROI) for dynamic analysis performed on dynamic images acquired by dynamic photography, or the target value for an index indicating image quality, and is the minimum image quality required to perform dynamic analysis accurately.

[0040] In the example of the imaging condition table shown in Figure 2, "Analysis 1," "Analysis 2," and "Analysis 3" are the major categories. Specifically, "Analysis 1" is the case where there is no dynamic analysis, or where the dynamic analysis item is "FE-mode: frequency emphasis processing" or "BS-mode: bone attenuation processing." "Analysis 2" is the case where the dynamic analysis item is "PL-mode: processing to extract signal value changes associated with breathing" or "DM-mode: processing to track specific components in diaphragm displacement." "Analysis 3" is the case where the dynamic analysis item is "PH-mode: processing to extract signal value changes associated with vascular pulsation." The dynamic analysis items are not limited to the above items, and may be other items.

[0041] FIG. 3A shows the relationship between the S value, which is an index indicating image quality, and the BMI of the patient being the subject. The S value corresponds to the density of the output image obtained as a result of normalization processing when a subject is photographed under given shooting conditions. It also corresponds to the film sensitivity required when trying to finish the reference signal value set in the ROI to the density specified by the density DL (density of the low-density area) and DH (density of the high-density area). The S value is inversely proportional to the reference signal value, and since the reference signal value is proportional to the dose, the S value is inversely proportional to the dose. Therefore, a lower S value indicates higher image quality, and a higher S value indicates lower image quality. The S value can be calculated using various conventionally known techniques (for example, techniques described in JP 2018-149166 A, JP 2010-188041 A, etc.). In this embodiment, an EI (Exposure Index) value, which is an industry standard dose index value, may be used instead of the S value. Alternatively, a signal value proportional to the dose irradiated to the radiation detection unit 13 may be used as is. In addition, the S value, which is an index indicating image quality (sometimes called a sensitivity index), has a different definition and name depending on the manufacturer (each radiography system), but it can be applied in the same way to other different indices.

[0042] There is a correlation between the S value and the patient's BMI, which can be expressed as a linear or exponential approximation (Figure 3A shows the case of linear approximation). Therefore, as shown in Figure 2, the patient's BMI can be used to classify the imaging conditions. That is, the imaging condition table provides imaging condition B (tube voltage value, tube current value, pulse time) which is the second imaging condition based on the target image quality, with the patient's BMI (Body Mass Index) value, which is the second order information, as a minor classification. That is, the imaging condition table (second table) shows the relationship between the target image quality and the second order information and the second imaging condition. In the example shown in FIG. 2, BMI is classified into sub-categories of 10 or more and less than 20, 20 or more and less than 30, 30 or more and less than 40, and 40 or more.

[0043] Figure 3B shows the relationship between the mAs value (tube current time product) and the patient's BMI to obtain the target S value (or target signal value) that achieves the target image quality. The mAs value is the product of the tube current value (mA) and the irradiation time (sec). There is a correlation between the mAs value and the patient's BMI, which can be expressed as a linear or exponential approximation (Figure 3B shows the case of linear approximation). Therefore, as shown in Figure 2, when the tube current value is constant, the pulse time is set so that the higher the patient's BMI, the longer the pulse time (resulting in a larger mAs value).

[0044] In the imaging condition table, the first order information may be a breathing protocol, and the breathing protocol may be a major classification. In this case, the imaging condition table (first table) provides the dynamic analysis items (or the presence or absence of dynamic analysis), imaging condition A, and target image quality.

[0045] [Configuration of Diagnostic Console 3] The diagnostic console 3 acquires dynamic images from the imaging console 2, analyzes the acquired dynamic images, generates images and various data as analysis results, and displays the generated analysis results to provide information to assist the doctor in making a diagnosis. As shown in FIG. 1, the diagnostic console 3 comprises a control unit 31, a storage unit 32, an operation unit 33, a display unit , and a communication unit , and each unit is connected by a bus .

[0046] The control unit 31 is composed of a CPU, RAM, etc. The CPU of the control unit 31 reads out the system program and various processing programs stored in the storage unit 32 in response to an operation of the operation unit 33, loads them into the RAM, executes various processes according to the loaded programs, and centrally controls the operations of each unit of the diagnostic console 3.

[0047] The storage unit 32 is configured with a non-volatile semiconductor memory, a hard disk, etc. The storage unit 32 stores various programs, including programs for executing image analysis processing, dynamic analysis processing, etc. in the control unit 31, as well as parameters required for executing processing by the programs, data such as processing results, etc. These various programs are stored in the form of readable program code, and the control unit 31 sequentially executes operations in accordance with the program code.

[0048] The operation unit 33 is configured with a keyboard having cursor keys, numeric input keys, various function keys, etc., and a pointing device such as a mouse, and outputs instruction signals input by operating the keys on the keyboard or the mouse to the control unit 31. The operation unit 33 may also have a touch panel on the display screen of the display unit 34, and in this case, outputs instruction signals input via the touch panel to the control unit 31.

[0049] The display unit 34 is configured with a monitor such as an LCD or CRT, and performs various displays according to instructions of a display signal input from the control unit 31.

[0050] The communication unit 35 includes a LAN adapter, a modem, a TA, etc., and controls data transmission and reception between each device connected to the communication network NT.

[0051] [Operation of imaging console 2] Next, the operation of the radiography console 2 as the radiography control device will be described. The control unit 21 of the imaging console 2 executes imaging condition determination processing shown in FIG. 4 when a predetermined condition is met (such as receiving imaging order information from the host system 200). The imaging order information includes the type of still or video imaging, whether or not dynamic analysis will be performed on the captured images, the dynamic analysis items, patient information of the subject (patient's name, age, height, weight, BMI), imaging area (front / side of chest), imaging direction, etc.

[0052] In the imaging condition determination process, first, the control unit 21 acquires the presence or absence of dynamic analysis or dynamic analysis items as first order information from the received imaging order information (step S1). Next, the control unit 21 refers to the imaging condition table and determines a breathing protocol, imaging condition A (first imaging condition), and target image quality based on the presence or absence of dynamic analysis or the dynamic analysis items acquired in step S1 (step S2). Specifically, when the dynamic analysis item acquired in step S1 is "PL-mode," in the example shown in Figure 2, the breathing protocol is "deep breathing," the shooting position as shooting condition A is "standing," the SID is 180 [cm], the frame rate is 10 [FPS], the shooting time is 15 [sec], and the target image quality (here, as an example, the target S value) is 4500.

[0053] Next, the control unit 21 acquires the patient's BMI as second order information from the received radiography order information (step S3). In step S3, the control unit 21 may acquire the height and weight of the patient from the radiography order information, and calculate the BMI from the height and weight.

[0054] Next, the control unit 21 refers to the imaging condition table and determines imaging condition B (second imaging condition) based on the target image quality determined in step S2 and the patient's BMI acquired in step S3 (step S4), and ends this processing. Specifically, when the target image quality determined in step S2 is 4500 and the patient's BMI obtained in step S3 is 20, in the example shown in FIG. 2, the imaging condition B is a tube voltage value of 100 kV, a tube current value of 32 mA, and a pulse time of 4 msec. Then, the control unit 21 outputs the imaging condition A determined in step S2 and the imaging condition B determined in step S4 to the imaging device 1 as imaging conditions for dynamic imaging.

[0055] (Variation) Next, a modification of the above embodiment will be described. The following description will focus on the differences from the above embodiment. The configuration of the radiation imaging system 100 of this modified example is the same as that of the radiation imaging system 100 of the above embodiment.

[0056] In this modification, the control unit 21 calculates the total exposure dose in dynamic imaging based on the first imaging condition determined by the first determination unit and the second imaging condition determined by the second determination unit. Here, the control unit 21 functions as a calculation unit. The control unit 21 also determines whether the total radiation exposure calculated by the calculation unit is greater than a predetermined value. Here, the control unit 21 functions as a determination unit. Furthermore, the control unit 21 issues an alert when the determination unit determines that the total radiation exposure dose is greater than a predetermined value. Here, the control unit 21 functions as a notification control unit. Furthermore, when the determination unit determines that the total exposure dose is greater than a predetermined value, the control unit 21 causes the display unit to display a suggestion to lower the frame rate in dynamic imaging or shorten the imaging time for dynamic imaging. Here, the control unit 21 functions as a display control unit.

[0057] FIG. 5 shows an example of an imaging condition table in this modified example. The imaging condition table of this modification, like the imaging condition table of the above embodiment, provides a respiratory protocol, imaging condition A, and target image quality based on the dynamic analysis items or presence or absence of dynamic analysis, which are the first order information included in the imaging order information, as a major classification. Also, the patient's BMI, which is the second order information, is provided as a minor classification, and imaging condition B based on the target image quality is provided. Furthermore, the imaging condition table of this modification provides the radiation dose for each frame image based on the imaging condition B.

[0058] In this modified example, the control unit 21 of the imaging console 2 executes the modified imaging condition determination process shown in Figure 6 when a predetermined condition is met (such as receiving imaging order information from the upper system 200).

[0059] In the photographing condition determination process of this modified example, the control unit 21 performs steps S11 to S13 similar to steps S1 to S3 of the photographing condition determination process of the above embodiment. Next, the control unit 21 refers to the imaging condition table and determines imaging condition B (second imaging condition) and the exposure dose for each frame image based on the target image quality determined in step S12 and the patient's BMI obtained in step S13 (step S14). For example, if the target image quality determined in step S12 is 3000 and the patient's BMI obtained in step S13 is 40 (condition C shown in FIG. 5), in the example shown in FIG. 5, the imaging condition B is a tube voltage value of 100 kV, a tube current value of 32 mA, a pulse time of 7 msec, and an exposure dose per frame image of 18 μGy / 1f.

[0060] Next, the control unit 21 calculates the total radiation exposure amount, which is the radiation exposure amount in one dynamic imaging, based on the imaging condition A determined in step S12 and the radiation exposure amount for each frame image determined in step S14 (step S15). For example, in the case of condition C shown in Figure 5, the frame rate under imaging condition A is 15 [FPS], the imaging time is 7 [sec], and the radiation dose per frame image is 18 [μGy / 1f]. In this case, the total radiation dose is 18 [μGy / 1f] × 15 [FPS] × 7 [sec] = 1890 [μGy].

[0061] Next, the control unit 21 determines whether or not the total exposure dose calculated in step S15 is greater than a predetermined value (step S16). The predetermined value is a value that has little effect on the human body (for example, 1500 [μGy]), and can be arbitrarily set via the operation unit 23 or the communication unit 25. If the total exposure dose is equal to or less than the predetermined value (step S16; NO), the control unit 21 ends this process. Then, the control unit 21 outputs the imaging condition A determined in step S12 and the imaging condition B determined in step S14 to the imaging device 1 as imaging conditions for dynamic imaging.

[0062] Furthermore, if the total radiation exposure dose is greater than the predetermined value (step S16; YES), the control unit 21 displays an alert on the display unit 24 to the effect that the total radiation exposure dose is greater than the predetermined value. Then, the control unit 21 issues the alert and displays on the display unit 24 a suggestion to reduce the frame rate or the imaging time, which is imaging condition A (step S17). Next, the control unit 21 determines whether or not the frame rate or the shooting time, which is the shooting condition A, has been adjusted by the user's input operation via the operation unit 23 (step S18). If the frame rate or the shooting time is not adjusted (step S18; NO), the control unit 21 returns the process to step S 18. That is, the control unit 21 waits until the frame rate or the shooting time is adjusted by the user.

[0063] Moreover, if the frame rate or the shooting time has been adjusted (step S18; YES), the control unit 21 shifts the process to step S15. In step S15, the control unit 21 calculates the total exposure dose based on the value adjusted in step S18. For example, in step S18, if the user changes the frame rate from condition C shown in Figure 5 to 10 [FPS], the total radiation exposure is 18 [μGy / 1f] × 10 [FPS] × 7 [sec] = 1260 [μGy]. If the total exposure dose calculated based on the value adjusted in step S18 is equal to or less than the predetermined value (step S16; NO), the control unit 21 ends this process. Then, the control unit 21 outputs to the imaging device 1, as imaging conditions for dynamic imaging, the frame rate or imaging time adjusted in step S18, the imaging condition A other than the frame rate or imaging time adjusted in step S18 and determined in step S12, and the imaging condition B determined in step S14.

[0064] As described above, by adjusting the frame rate or imaging time so that the total radiation exposure does not exceed a predetermined value, it is possible to determine imaging conditions for safe dynamic imaging that have little effect on the human body.

[0065] (Test screen) Next, an examination screen to be displayed on the display unit 24 when the control unit 21 receives imaging order information from the host system 200 will be described. FIG. 7 shows an example of an examination screen 241 displayed on the display unit 24.

[0066] Based on the received imaging order information, the control unit 21 displays the imaging conditions (imaging conditions A and B) determined in the imaging condition determination process on a display 2411 within the examination screen 241. In the example shown in Fig. 7, the tube voltage value, tube current value, pulse time, frame rate, and imaging time are displayed as the imaging conditions.

[0067] Furthermore, the control unit 21 displays the dynamic analysis items and the patient's BMI included in the received radiography order information in a display 2413 of the radiography condition tab 2412 in the examination screen 241. Furthermore, in the display 2413, the control unit 21 displays the breathing protocol and radiography position determined in the radiography condition determination process based on the received radiography order information.

[0068] Furthermore, based on the received imaging order information, the control unit 21 displays the imaging conditions (imaging conditions A and B) determined in the imaging condition determination process in the display 2414 of the imaging condition tab 2412. In the example shown in Fig. 7, the tube voltage value, tube current value, pulse time, frame rate, and imaging time are displayed as the imaging conditions.

[0069] Furthermore, in the imaging condition determination process of the above-described modified example, the control unit 21 accepts adjustment of the imaging conditions by a user's input operation via the adjustment buttons 2415 of the imaging condition tab 2412. In the example shown in Fig. 7, by pressing the "+" button or "-" button of the adjustment buttons 2415, the tube voltage value, tube current value, pulse time, frame rate, and imaging time can be adjusted. Then, when the control unit 21 receives the adjustment of the imaging conditions, it displays the adjusted imaging conditions on the displays 2411 and 2414.

[0070] 7, the display 2414 displays the tube current value and pulse time as imaging conditions, and the imaging conditions are configured to be adjustable via the adjustment button 2415. However, the imaging conditions are not limited to this. Instead of the tube current value and pulse time, the display 2414 may display the mAs value, and the mAs value may be adjusted via the adjustment button 2415.

[0071] FIG. 8 shows an example of an examination screen 241 in a form different from that shown in FIG. The following mainly describes the differences from FIG.

[0072] In the example shown in FIG. 8, the control unit 21 receives the selection of dynamic analysis items, a breathing protocol, and an imaging position through an input operation by the user via the selection button 2416 of the imaging condition tab 2412. For example, the dynamic analysis item can be selected from "FE-MODE", "BS-MODE", "PL-MODE", and "DM-MODE" via the selection button 2416. Note that multiple dynamic analysis items may be selected. Also, for example, the breathing protocol can be selected from "deep breathing," "quiet breathing," and "breath holding" via the selection button 2416. Furthermore, for example, the photographing position can be selected from "standing front view," "standing side view," "lying front view," "lying side view," "sitting front view," and "sitting side view" via the selection button 2416. The control unit 21 may display a warning on the examination screen 241 when the combination of dynamic analysis items and breathing protocols selected by the user's input operation is not preferable. Then, when the control unit 21 receives the selection of the dynamic analysis items, breathing protocol, and imaging position, it displays the selected dynamic analysis items, breathing protocol, and imaging position on the display 2413. As shown in FIGS. 7 and 8, the imaging conditions can be manually changed or corrected by the user's input operation.

[0073] As described above, the imaging console 2 (imaging control device) in this embodiment is an imaging control device that controls dynamic imaging, which irradiates radiation onto a subject and captures the dynamics of the subject by acquiring multiple frame images, and is equipped with a first acquisition unit (control unit 21) that acquires first order information including at least one of information on whether or not dynamic analysis is to be performed on the dynamic image acquired by dynamic imaging and information on the dynamic analysis items, a first determination unit (control unit 21) that determines first imaging conditions and target image quality based on the first order information acquired by the first acquisition unit, and a second determination unit (control unit 21) that determines second imaging conditions to achieve the target image quality determined by the first determination unit. Therefore, it is possible to set imaging conditions that are more suitable for dynamic imaging based on the information on whether or not dynamic analysis is performed, which is the first order information, and the information on the dynamic analysis items.

[0074] In the imaging console 2 of this embodiment, the first order information includes instruction information (breathing protocol) regarding the breathing of the subject during dynamic imaging. Therefore, it is possible to set imaging conditions that are more suitable for dynamic imaging based on the breathing protocol, which is the first order information.

[0075] In the imaging console 2 of this embodiment, the first determination unit determines the first imaging conditions based on a first table indicating the relationship between the first order information and the first imaging conditions. Therefore, imaging conditions that are more suitable for dynamic imaging can be easily set based on the first table.

[0076] In the imaging console 2 of this embodiment, the first imaging condition includes any one of the subject's body position during dynamic imaging, the distance between the radiation source and the radiation detection unit that generates an image corresponding to the radiation irradiated from the radiation source, the frame rate during dynamic imaging, and the imaging time during dynamic imaging. Therefore, it is possible to set imaging conditions that are more suitable for dynamic imaging, such as the subject's body position, the distance between the radiation source and the radiation detection unit, the frame rate, and the imaging time.

[0077] In addition, the imaging console 2 in this embodiment is equipped with a second acquisition unit (control unit 21) that acquires second order information, which is information regarding the imaging area, and a second determination unit determines second imaging conditions based on the target image quality and the second order information. Therefore, it is possible to set imaging conditions that are more suitable for dynamic imaging based on the target image quality and second order information.

[0078] In the imaging console 2 of this embodiment, the second order information includes the BMI of the subject. Therefore, it is possible to set imaging conditions that are more suitable for dynamic imaging based on the BMI of the subject, which is the second order information.

[0079] In the imaging console 2 of this embodiment, the second determination unit determines the second imaging conditions based on a second table indicating the relationship between the target image quality, the second order information, and the second imaging conditions. Therefore, imaging conditions that are more suitable for dynamic imaging can be easily set based on the second table.

[0080] In the imaging console 2 of this embodiment, the second imaging condition includes any one of the tube voltage, tube current, and radiation irradiation time per frame image in the radiation source. Therefore, it is possible to set the tube voltage, tube current, and radiation irradiation time per frame image of the radiation source, which are imaging conditions more suitable for dynamic imaging.

[0081] Furthermore, in the imaging console 2 of this embodiment, the first determination unit determines the target signal value of the region of interest in the frame image or the target value of an index indicating image quality as the target image quality based on the first order information, and the second determination unit determines the second imaging conditions that can achieve the target signal value or the target value of an index indicating image quality. Therefore, it is possible to easily determine the imaging conditions that achieve the target signal value of the region of interest in the frame image or the target value of the index indicating the image quality.

[0082] In addition, the imaging console 2 in this embodiment is equipped with a calculation unit (control unit 21) that calculates the total radiation exposure amount in dynamic imaging based on the first imaging condition determined by the first determination unit and the second imaging condition determined by the second determination unit, a judgment unit (control unit 21) that determines whether the total radiation exposure amount calculated by the calculation unit is greater than a predetermined value, and a notification control unit (control unit 21) that issues an alert when the judgment unit determines that the total radiation exposure amount is greater than the predetermined value. Therefore, if the total radiation exposure is greater than a safe value that has minimal impact on the human body, an alert can be issued to notify the user.

[0083] In addition, the imaging console 2 in this embodiment is equipped with a display control unit (control unit 21) that displays on the display unit 24 a suggestion to lower the frame rate in dynamic imaging or shorten the imaging time for dynamic imaging when the judgment unit determines that the total exposure dose is greater than a predetermined value. Therefore, by adjusting the frame rate or imaging time so that the total radiation exposure does not exceed a safe value that has minimal impact on the human body, it is possible to determine imaging conditions for safe dynamic imaging that has minimal impact on the human body.

[0084] Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments and that various modifications are possible without departing from the spirit of the present invention.

[0085] For example, in the present embodiment, the case where the imaging console 2 functions as an imaging control device has been exemplified, but the imaging control device is not limited to this. For example, the diagnostic console 3 may be configured to function as an imaging control device.

[0086] In addition, in this embodiment, the distance (SID) between the radiation source 11 and the radiation detection unit 13, which is imaging condition A, is determined based on the presence or absence of dynamic analysis or the dynamic analysis items, which are the first order information, but this is not limited to this. If the radiation imaging system 100 is a medical cart, it may be provided with a detection unit that detects the actual SID, and the SID may be determined based on the detection result of the detection unit. In addition, in this embodiment, the photographing position, which is the photographing condition A, is determined based on the presence or absence of dynamic analysis or the dynamic analysis items, which are the first order information, but this is not limitative and may be determined based on other conditions.

[0087] In this embodiment, the second order information is the BMI of the subject, but is not limited to this. The second order information may be the subject's height, weight, body thickness, and the chest front / side as the imaging region, etc.

[0088] In the present embodiment, the BMI values ​​of the subjects are used as minor categories in the photographing condition table, but this is not limiting. BMI levels (underweight, normal weight, obesity level 1, etc.) may also be used as minor categories. In the present embodiment, the BMI of the subject is classified into sub-categories in the imaging condition table, such as BMI of 10 or more and less than 20, 20 or more and less than 30, 30 or more and less than 40, and 40 or more, but this is not limiting. In the imaging condition table, BMI may be classified into sub-categories in increments of 1 (for example, BMI of 10 or more and less than 11) or in increments of 5 (for example, BMI of 10 or more and less than 15).

[0089] Furthermore, the photographing condition table is not limited to the examples shown in FIGS. The relationship between the S value and the patient's BMI as shown in FIG. 3A or the relationship between the mAs value and the patient's BMI as shown in FIG. 3B may be fed back to update the imaging condition table. Furthermore, the change in the actual radiation output relative to the set value over time due to deterioration of the radiation source 11 or the like may be reflected in the imaging condition table.

[0090] Furthermore, the combination of tube current and pulse time under imaging condition B is not limited to the examples shown in Figures 2 and 5. As shown in Figure 3B, there is a correlation between the patient's BMI and the mAs value, which is expressed by a linear approximation, so it is possible to arbitrarily set a combination of tube current and pulse time that can achieve a mAs value corresponding to the patient's BMI. Furthermore, the mAs value may be calculated based on the patient's BMI using an approximation formula such as linear approximation, polynomial approximation, or exponential approximation (logarithmic approximation), and the imaging conditions may be determined from the calculated mAs value.

[0091] 2 and 5, a Cu 0.2 mm additional filter is used, but the additional filter is not limited to this. If the additional filter is different, the radiation quality (tube voltage) and dose (mAs value) will also be different. Therefore, when using a different additional filter (filter type, filter thickness, etc.), it is desirable to create an imaging condition table based on the conditions.

[0092] Furthermore, in radiography using the radiation imaging system 100, radiation is applied under predetermined reference imaging conditions without placing a subject in advance, and a solid image (uniform exposure image) is captured to be read. Then, calibration is performed by matching the output of the radiation source 11 with the sensitivity (signal value) of the radiation detection unit 13 based on the signal value of the radiation detection unit 13 when capturing the uniform exposure image. Thereafter, the imaging conditions may be determined by the imaging condition determination process, and imaging may be performed. The calibration of the radiation source 11 and the radiation detection unit 13 is preferably performed at predetermined intervals (for example, daily, once a week, etc.).

[0093] In addition, in this embodiment, the user can adjust the tube voltage value, tube current value, pulse time, frame rate, and imaging time through input operations as shown in Figures 7 and 8, and can select dynamic analysis items, breathing protocol, and imaging position as shown in Figure 8, but this is not limited to this. The system may be configured so that the distance (SID) between the radiation source 11 and the radiation detection unit 13 or the target image quality can be adjusted through input operations by the user. When the SID or target image quality is changed from the value in the imaging condition table through input operations by the user, the imaging condition B may be changed accordingly.

[0094] In addition, the detailed configuration and detailed operation of each part constituting the imaging control device (the imaging console 2 in this embodiment) can also be modified as appropriate within the scope of the present invention. [Explanation of symbols]

[0095] 100 Radiography System 1. Imaging device 11 Radiation source 12 Radiation exposure control device 13 Radiation detection unit 14 Reading control device 2. Imaging console (imaging control device) 21 control unit (first acquisition unit, second acquisition unit, first determination unit, second determination unit, calculation unit, determination unit, notification control unit, display control unit) 22 Memory section 23 Control section 24 Display section 25 Communications Department 26 Bus 3 Diagnostic Console 31 Control Unit 32 Storage section 33 Operation section 34 Display section 35 Communications Department 36 Bus

Claims

1. An imaging control device that controls dynamic imaging for imaging dynamics of a subject by irradiating the subject with radiation and acquiring a plurality of frame images, a first acquisition unit that acquires first order information including at least one of information on whether or not a dynamic analysis is to be performed on the dynamic image acquired by the dynamic imaging and information on dynamic analysis items; a first determination unit that determines a first photographing condition and a target image quality based on the first order information acquired by the first acquisition unit; a second determination unit that determines a second photographing condition for achieving the target image quality determined by the first determination unit; a second acquisition unit that acquires second order information, which is information related to the imaging region; Equipped with The second determination unit determines the second photographing condition based on the target image quality and the second order information.

2. The imaging control device according to claim 1 , wherein the first order information includes instruction information regarding breathing of the subject during the dynamic imaging.

3. The imaging control device according to claim 1 , wherein the first determination unit determines the first imaging condition based on a first table indicating a relationship between the first order information and the first imaging condition.

4. 4. The imaging control device according to claim 1, wherein the first imaging condition includes any one of a body position of the subject during the dynamic imaging, a distance between a radiation source and a radiation detection unit that generates an image according to radiation irradiated from the radiation source, a frame rate during the dynamic imaging, and an imaging time for the dynamic imaging.

5. The imaging control device according to claim 1 , wherein the second order information includes a BMI of the subject.

6. 6. The imaging control device according to claim 1, wherein the second determination unit determines the second imaging condition based on a second table indicating a relationship between the target image quality, the second order information, and the second imaging condition.

7. The imaging control device according to claim 1 , wherein the second imaging condition includes any one of a tube voltage, a tube current, and a radiation irradiation time per frame image in a radiation source.

8. the first determination unit determines, based on the first order information, a target signal value of a region of interest in the frame image or a target value of an index indicating image quality as the target image quality; The imaging control device according to claim 1 , wherein the second determination unit determines the second imaging condition that can achieve the target signal value or a target value in the index indicating the image quality.

9. a calculation unit that calculates a total exposure dose in the dynamic radiography based on the first radiography condition determined by the first determination unit and the second radiography condition determined by the second determination unit; a determination unit that determines whether the total exposure dose calculated by the calculation unit is greater than a predetermined value; a notification control unit that issues an alert when the determination unit determines that the total exposure dose is greater than a predetermined value; and The imaging control device according to claim 1 , comprising:

10. 10. The imaging control device according to claim 9, further comprising a display control unit that, when the determination unit determines that the total exposure dose is greater than a predetermined value, displays on a display unit a suggestion to lower the frame rate in the dynamic imaging or to shorten the imaging time for the dynamic imaging.

11. a computer of an imaging control device that controls dynamic imaging to capture dynamic images of a subject by irradiating the subject with radiation and acquiring a plurality of frame images; a first acquisition unit that acquires first order information including at least one of information on whether or not a dynamic analysis is to be performed on the dynamic image acquired by the dynamic imaging and information on dynamic analysis items; a first determination unit that determines a first photographing condition and a target image quality based on the first order information acquired by the first acquisition unit; a second determination unit that determines a second photographing condition for achieving the target image quality determined by the first determination unit; a second acquisition unit that acquires second order information, which is information related to the imaging region; It functions as The second determination unit is a program that determines the second shooting condition based on the target image quality and the second order information.

12. The imaging control device according to any one of claims 1 to 10; an external device connected to the imaging control device and transmitting the first order information and the second order information; A radiography system comprising:

Images