Kymographic apparatus and breath-holding failure determination program

Abstract

To enhance reliability of breath-holding failure determination.SOLUTION: A kymographic apparatus comprises: a waveform acquisition part that acquires a lung field signal waveform regarding a lung field and a periodic signal waveform synchronous with a heartbeat from a dynamic image acquired in radiation kymography based on photographing conditions including breath-holding instructions; and a determination part that determines the occurrence of a breath-holding failure during the radiation kymography, on the basis of the result of comparison between the acquired lung field signal waveform and the acquired periodic signal waveform.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a dynamic radiography apparatus and a program for determining insufficient breath-holding. [Background technology]

[0002] Dynamic imaging devices are known that irradiate a patient's chest with radiation to capture dynamic images of the chest. Dynamic analysis of the captured dynamic images can be used to diagnose, for example, the state of lung ventilation and pulmonary blood flow. Depending on the diagnostic content, for example, when diagnosing pulmonary blood flow, it is desirable to capture dynamic images while the patient is holding their breath so that lung movement does not appear in the dynamic images.

[0003] For example, in the device disclosed in Patent Document 1, in the breath-hold heart rate mode, a breathing condition of 0 and a heart rate condition of 8 are set, and when these conditions are met, radiation irradiation is terminated and dynamic images are taken in a breath-hold state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-51012 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, breath-holding is determined based on the respiratory rate, so even if there is slight improper breath-holding, the respiratory rate may be determined to be 0. Even slight improper breath-holding may prevent correct dynamic analysis of dynamic images, and there is a risk that analysis results may not be obtained or artifacts may occur. Therefore, in order to correctly perform dynamic analysis of dynamic images, it is necessary to more accurately determine improper breath-holding.

[0006] An object of the present invention is to provide a dynamic radiography apparatus and a program for determining inadequate breath-holding that can improve the reliability of determining inadequate breath-holding. [Means for solving the problem]

[0007] The dynamic radiography apparatus according to the present invention comprises: a waveform acquisition unit that acquires a lung field signal waveform and a periodic signal waveform synchronized with a heartbeat from a dynamic image acquired in a radiographic dynamic imaging that includes a breath-hold instruction as an imaging condition; a determination unit that determines whether poor breath-holding has occurred during the radiographic dynamic imaging based on a comparison result between the acquired lung field signal waveform and the acquired periodic signal waveform; Equipped with.

[0008] The inadequate breath-holding determination program according to the present invention comprises: On the computer, A process of acquiring a lung field signal waveform and a periodic signal waveform synchronized with a heartbeat from a dynamic image acquired in a radiographic dynamic imaging including a breath-hold instruction as an imaging condition; a process of determining whether poor breath-holding has occurred during the radiographic dynamic imaging based on a comparison result between the acquired lung field signal waveform and the acquired periodic signal waveform; Execute the following. [Effects of the Invention]

[0009] According to the present invention, it is possible to improve the reliability of the determination of inadequate breath-holding. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram showing an example of the configuration of a radiation image processing system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram illustrating an example of the functional configuration of an imaging control unit in a radiation image imaging device that constitutes the radiation image processing system. [Figure 3] FIG. 3 is a block diagram illustrating an example of the functional configuration of a radiation imaging control device that constitutes the radiation image processing system. [Figure 4] FIG. 4 is a block diagram illustrating an example of the functional configuration of a radiation image analysis device that constitutes a radiation image processing system. [Figure 5] FIG. 5 is a flowchart illustrating the process of determining whether breath-holding is inadequate, which is performed by the radiation imaging control device. [Figure 6] FIG. 6 is a diagram illustrating a first region of interest from which a periodic signal waveform is acquired and a second region of interest from which a lung field signal waveform is acquired in one frame of a dynamic image captured by a radiation imaging device and a radiation imaging control device. [Figure 7A] FIG. 7A is a graph comparing, on the time axis, periodic signal waveforms and lung field signal waveforms acquired from the first and second regions of interest shown in FIG. 6, and shows a case where there is no poor breath-holding. [Figure 7B] FIG. 7B is a graph comparing, on the time axis, periodic signal waveforms and lung field signal waveforms acquired from the first and second regions of interest shown in FIG. 6, and shows a case where breath-holding is poor. [Figure 8] FIG. 8 is a graph showing a frequency spectrum obtained by Fourier transforming a periodic signal waveform and a lung field signal waveform. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0012] <Configuration of Radiation Image Processing System> 1 is a diagram illustrating a radiographic image processing system 1 according to the present embodiment. The radiographic image processing system 1 includes a radiographic image capturing device 10, a radiographic image control device (console device) 20, a radiographic image analysis device 30, an image management device 40, and a client terminal 50. The radiographic image capturing device 10 and the radiographic image control device 20 correspond to the dynamic radiographic device of the present invention.

[0013] 1, the radiographic imaging device 10 is placed in an imaging room, and the radiographic imaging control device 20 is placed in an operation room. The radiographic imaging device 10, the radiographic imaging control device 20, the radiographic image analysis device 30, the image management device 40, and the client terminal 50 are connected to each other via a communication network N. As the communication network N, for example, a communication network conforming to the DICOM (Digital Image and Communications in Medicine) standard or the like is used.

[0014] Also connected to the communication network N is a radiation information terminal 60, such as a RIS (Radiology Information System), which serves as a radiation information system that transmits information relating to radiation examinations, such as examination order information for patients, to the radiation image processing system 1.

[0015] The radiographic imaging device 10 performs radiographic dynamic imaging (hereinafter referred to as dynamic imaging), which is the capturing of dynamic images of radiographic images, under the control of the radiographic imaging control device 20. The radiographic imaging control device 20 controls the radiographic imaging device 10 based on examination order information, etc., transmitted from the radiographic information terminal 60. The dynamic images generated by the radiographic imaging device 10 are processed by the radiographic imaging control device 20 as described below and transmitted to the radiographic image analysis device 30. The radiographic image analysis device 30 performs dynamic analysis on the dynamic images. The dynamic images and the results of the dynamic analysis are transmitted to and managed by an image management device 40, which serves as a medical image management system, such as a PACS (Picture Archiving and Communication System). The dynamic images and the results of the dynamic analysis are transmitted to a client terminal 50 and viewed by medical professionals such as doctors.

[0016] In this embodiment, dynamic imaging refers to repeatedly irradiating a subject with pulsed radiation (e.g., X-rays) at a predetermined frame rate (pulse irradiation) to obtain multiple frames. Dynamic images refer to a series of frames obtained by dynamic imaging. Dynamic analysis refers to analytical processing performed on dynamic images, and includes processing to analyze the movement of the subject based on the dynamic images, as well as processing to analyze the dynamic images and emphasize or attenuate (remove) predetermined structures.

[0017] The radiographic imaging device 10, the radiographic imaging control device 20, and the radiographic image analysis device 30 each have a processor and memory, and are a type of computer that realizes specified functions by reading, expanding, and executing programs stored in the memory.

[0018] [Radiation imaging device 10] As shown in FIG. 1, the radiographic imaging device 10 includes an imaging control unit 11, a radiation irradiation unit 12, an imaging table 13, a radiation detection unit 14, a display unit 15, and an audio output unit 16.

[0019] The imaging control unit 11 acquires setting information related to the settings of dynamic imaging from the radiation imaging control device 20. Based on the setting information, the imaging control unit 11 sets imaging conditions for performing dynamic imaging, and controls the radiation irradiator 12 based on the imaging conditions to irradiate radiation to the patient M (subject) and perform imaging. The imaging control unit 11 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc.

[0020] The setting information is information relating to settings for performing dynamic radiography on the patient M. The setting information includes, for example, at least one of multiple types of dynamic analysis that the radiographic image analysis device 30 can perform on dynamic images. When multiple types of dynamic analysis are combined, the setting information may include information relating to the combination. The setting information is set by an operator of the radiographic image processing system 1, for example, a radiographer, in the radiography control device 20 described below.

[0021] The imaging conditions include various conditions such as the pulse rate, pulse width, pulse interval, number of frames captured per imaging, radiation dose per unit time, and the physical condition of the patient M (such as respiratory condition). The pulse rate is the number of radiation exposures per second and corresponds to the frame rate of the image data. The pulse width is the radiation exposure time per radiation exposure. The pulse interval is the time from the start of one radiation exposure to the start of the next radiation exposure and corresponds to the time interval (frame interval) between multiple image data. The imaging conditions may be automatically determined by the imaging control unit 11 of the radiographic imaging device 10 based on the setting information.

[0022] The radiation irradiator 12 is disposed at a position facing the radiation detector 14 fixed to the imaging table 13. The radiation irradiator 12 irradiates radiation under the control of the imaging controller 11.

[0023] The radiation detection unit 14 is composed of a semiconductor image sensor such as an FPD (Flat Panel Detector). The radiation detection unit 14 has a substrate on which a plurality of detection elements (pixels) are arranged in a matrix, which detect radiation irradiated from the radiation irradiation unit 12 according to its intensity, convert the detected radiation into an electrical signal, and store the electrical signal. Each pixel on the substrate is configured to include a switching unit such as a TFT (Thin Film Transistor).

[0024] The radiation detection unit 14 controls the switching unit of each pixel based on the image reading conditions input from the radiation imaging control device 20 to read the electrical signals accumulated in each pixel and output intensity information for each pixel to the image generation unit 113. 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 one image data acquisition operation to the start of the next frame image acquisition operation and coincides with the pulse interval.

[0025] The imaging control unit 11 and the radiation detection unit 14 are connected to each other and exchange synchronization signals with each other to synchronize the radiation irradiation operation and the image reading operation.

[0026] In this way, the radiographic imaging device 10 performs dynamic radiographic imaging by controlling the imaging control unit 11 so that the radiation irradiation unit 12 irradiates radiation and the radiation detection unit 14 generates image data based on the intensity of the irradiated radiation.

[0027] The display unit 15 and the audio output unit 16 give instructions to the patient M regarding the posture to be taken, physical condition, respiratory condition, etc. when performing dynamic radiography of the patient M. The display unit 15 is a display device such as a CRT (Cathode Ray Tube), a liquid crystal display (Liquid Crystal Display), or an organic EL (Electro Luminescence) display. The audio output unit 16 is an audio output device such as a speaker. The audio output unit 16 gives instructions regarding the respiratory condition to the patient M, for example, by autovoice. The display unit 15 and the audio output unit 16 may each give the same instructions to the patient M, or only one of them may give instructions.

[0028] 2 is a block diagram illustrating an example of the functional configuration of the imaging control unit 11 in the radiographic image capturing device 10 that constitutes the radiographic image processing system 1. The imaging control unit 11 has a setting information acquisition unit 111, an imaging condition determination unit 112, an image generation unit 113, and a storage unit 114.

[0029] The setting information acquisition unit 111 acquires setting information from the radiation imaging control device 20 .

[0030] The imaging condition determination unit 112 determines imaging conditions for performing dynamic imaging of the patient M based on the setting information. Information indicating the correspondence between multiple types of dynamic analysis and imaging conditions suitable for each dynamic analysis is stored in advance in the storage unit 114. Information indicating the correspondence between combinations of multiple types of dynamic analysis and imaging conditions suitable for that combination is also stored in advance in the storage unit 114. The imaging condition determination unit 112 may determine imaging conditions by reading information indicating the correspondence from the storage unit 114 for the dynamic analysis or combination of multiple types of dynamic analysis indicated in the setting information and comparing it with the setting information.

[0031] It should be noted that, for example, in the case of screening, emergency care, etc., it may not be possible to set dynamic analysis, which is the setting information. In such cases, the imaging condition determination unit 112 determines the imaging conditions by having the operator select at least one imaging condition from a plurality of predefined imaging conditions. Furthermore, the imaging condition determination unit 112 has the operator select examination order information, and determines the imaging conditions based on the selected examination order information. In this way, when dynamic analysis cannot be set before dynamic imaging, dynamic analysis is set after dynamic imaging under the imaging conditions selected by the operator, and dynamic analysis (analysis by the analysis unit 312, which will be described later) is performed in the radiographic image analyzer 30, which will be described later.

[0032] The image generation unit 113 performs dynamic imaging of the patient M based on the determined imaging conditions and generates multiple frames of radiographic images. Specifically, the image generation unit 113 controls the operations of the radiation irradiator 12 and the radiation detector 14 based on the imaging conditions, and generates image data by obtaining intensity information on the intensity of radiation that has passed through the subject from the radiation detector 14 for each pixel.

[0033] As described above, the memory unit 114 pre-stores information indicating the correspondence between multiple types of dynamic analysis and the imaging conditions suitable for each dynamic analysis, information indicating the correspondence between combinations of multiple types of dynamic analysis and the imaging conditions suitable for that combination, etc.

[0034] [Radiation imaging control device 20] The radiation imaging control device 20 is, for example, a computer such as a PC (Personal Computer), a workstation, etc. The radiation imaging control device 20 may be a desktop computer as shown in the example of Fig. 1, or may be a portable computer such as a notebook computer or a tablet computer.

[0035] The radiography control device 20 receives examination order information from the radiological information terminal 60 or the like, and transmits it to the radiographic image capturing device 10, thereby controlling dynamic radiography by the radiographic image capturing device 10.

[0036] The examination order information includes various information related to the dynamic imaging to be performed next, such as instruction information related to breathing, patient information, examination information, imaging information, data attributes, etc. The examination information includes information such as the examination ID, the area to be examined (e.g., chest, particularly lungs or heart, etc.), the type of analysis (e.g., ventilation analysis, pulmonary blood flow analysis, measurement of maximum ventilation volume, etc.). The examination order information is generated, for example, when a doctor or the like requests the radiological image processing system 1 to perform dynamic imaging of patient M.

[0037] Furthermore, based on input from the operator, the radiography control device 20 generates setting information indicating at least one of the multiple types of kinetic analyses that can be performed by the radiographic image analyzer 30. When multiple types of kinetic analyses are to be combined, the radiography control device 20 generates setting information indicating a combination of the multiple types of kinetic analyses. The operator, for example, refers to the contents of the examination order information to determine which of the multiple types of kinetic analyses to combine, and performs input operations to generate setting information based on this. Alternatively, the operator may determine which kinetic analyses to combine based on information provided by a doctor or the like in another manner.

[0038] 3 is a block diagram illustrating an example of the functional configuration of the radiation imaging control device 20 that constitutes the radiation image processing system 1. The radiation imaging control device 20 has a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25. The components of the radiation imaging control device 20 are connected to each other via a bus 26.

[0039] The radiography control device 20 outputs setting conditions set by an operator or the like and examination order information acquired in advance from a radiation information terminal 60 or the like to the radiography device 10, and controls the radiography processing by the radiography device 10. The radiography control device 20 may, for example, display dynamic images generated by the radiography device 10 so that the operator can check them.

[0040] The control unit 21 is configured with a CPU, RAM, etc. In the control unit 21, the CPU reads out the system program and various processing programs stored in the storage unit 22 in response to an operation of the operation unit 23, loads them into the RAM, and controls the operation of each unit of the radiation imaging control device 20 based on the loaded programs.

[0041] The control unit 21 includes a waveform acquisition unit 211 and a determination unit 212 .

[0042] The waveform acquisition unit 211 acquires a lung field signal waveform related to the lung field and a periodic signal waveform synchronized with the heartbeat from a dynamic image acquired during dynamic imaging that includes a breath-hold instruction as an imaging condition.

[0043] Here, the waveform acquisition unit 211 acquires the lung field signal waveform based on at least one of the changes in the position of the diaphragm, the changes in the shape of the diaphragm, the changes in the lung field area, the changes in the transmittance of the lung field, and the changes in the position of the ribs in the dynamic image.

[0044] Furthermore, the waveform acquisition unit 211 acquires a periodic signal waveform based on at least one of changes in signal intensity of the apex of the heart, changes in signal intensity of the right heart, and changes in signal intensity of the aorta in the dynamic image.

[0045] The determination unit 212 determines whether poor breath-holding has occurred during dynamic imaging based on the comparison result between the acquired lung field signal waveform and the periodic signal waveform.

[0046] Here, the determination unit 212 compares the pulmonary field signal waveform with the periodic signal waveform on the time axis, and acquires the comparison result from the comparison.

[0047] The determination unit 212 may obtain a comparison result by other comparisons than the above-described comparisons. For example, the determination unit 212 may compare the frequency spectrum of the pulmonary field signal waveform with the frequency spectrum of the periodic signal waveform, and obtain a comparison result by the comparison.

[0048] The determination unit 212 then determines whether inadequate breath-holding has occurred based on the similarity of the pulmonary field signal waveform to the periodic signal waveform. For example, when the pulmonary field signal waveform and the periodic signal waveform are compared on the time axis, the determination unit 212 determines whether inadequate breath-holding has occurred based on the similarity of the signal waveforms. Furthermore, when the frequency spectrum of the pulmonary field signal waveform and the frequency spectrum of the periodic signal waveform are compared, the determination unit 212 determines whether inadequate breath-holding has occurred based on the similarity of the frequency spectra.

[0049] The storage unit 22 is configured with 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, or data such as processing results (dynamic images, etc.). The various programs are stored in the form of readable program code, and the control unit 21 sequentially executes operations in accordance with the program code.

[0050] The storage unit 22 also stores image reading conditions for performing dynamic radiography. Furthermore, the storage unit 22 stores examination order information transmitted from the radiation information terminal 60, etc. When the radiation imaging control device 20 controls dynamic radiography of the radiation image capturing device 10, it reads out the image reading conditions and examination order information corresponding to the patient M from the storage unit 22 and transmits them.

[0051] The operation unit 23 is an operation device such as a keyboard equipped with cursor keys, numeric input keys, and various function keys, a pointing device such as a mouse or a trackball, and a touch panel. The operation unit 23 generates an instruction signal based on an input from the operator and outputs it to the control unit 21.

[0052] The display unit 24 is configured with a display device such as a CRT, a liquid crystal display, an organic EL display, etc. In accordance with instructions of a display signal input from the control unit 21, the display unit 24 displays input instructions from the operation unit 23, image data (dynamic images, etc.) generated by the radiographic image capturing device 10, etc.

[0053] The communication unit 25 transmits and receives data to and from the radiation image capturing device 10, the radiation image analyzing device 30, the radiation information terminal 60, and the like.

[0054] [Radiation image analyzer 30] The radiation image analysis device 30 is, for example, a computer such as a PC, a workstation, etc. The radiation image analysis device 30 may be a desktop computer or a portable computer such as a notebook computer or a tablet computer.

[0055] The radiographic image analysis device 30 performs dynamic analysis on the dynamic images captured by the radiographic image capturing device 10 based on the setting information set in the radiographic image capturing control device 20. The radiographic image analysis device 30 may perform a combination of multiple types of dynamic analysis.

[0056] 4 is a block diagram illustrating an example of the functional configuration of the radiographic image analysis device 30 that constitutes the radiographic image processing system 1. The radiographic image analysis device 30 has a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, and a communication unit 35. The components of the radiographic image analysis device 30 are connected by a bus 36.

[0057] The control unit 31 is configured with a CPU, RAM, etc. In the control unit 31, the CPU 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, expands them in the RAM, and performs operation control of each unit of the radiological image analysis device 30, dynamic analysis, etc. based on the expanded programs.

[0058] The control unit 31 includes an image acquisition unit 311 and an analysis unit 312 .

[0059] The image acquisition unit 311 acquires dynamic images, which are radiographic images of multiple frames generated by the radiographic image capturing device 10.

[0060] The analysis unit 312 executes the dynamic analysis set in the setting information on the dynamic image acquired from the radiographic image capturing device 10 and acquires the analysis result. At this time, if the analysis unit 312 cannot analyze the dynamic image (cannot acquire the analysis result), it determines that the analysis is not possible.

[0061] The analysis unit 312 has, as types of dynamic analysis, for example, a blood flow analysis mode, a ventilation analysis mode, an adhesion analysis mode, a diaphragm movement amount analysis mode, etc. Each mode will be briefly described below.

[0062] The blood flow analysis mode visualizes signal changes within the lung field that are synchronized with the heartbeat.

[0063] The ventilation analysis mode is a mode in which signal changes in the time direction in a specific time frequency band are extracted and the behavior of lung tissue during breathing is visualized.

[0064] The adhesion analysis mode is a mode for visualizing the degree of tissue adhesion.

[0065] The diaphragm movement amount analysis mode is a mode for tracking the up and down movement of the diaphragm that accompanies breathing.

[0066] In this embodiment, particularly when the blood flow analysis mode is executed, a determination is made before execution as to whether or not breath-holding is inadequate, as will be described later, for the dynamic image to be analyzed.

[0067] The storage unit 32 is configured with a non-volatile semiconductor memory, a hard disk, etc. The storage unit 32 stores various programs executed by the control unit 31, parameters required for executing processing by the programs, or data such as processing results (dynamic images, analysis results, etc.). The 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.

[0068] The storage unit 32 also stores list information indicating patient information, examination information, and status (e.g., progress status such as receiving, dynamic analysis in progress, analysis completed, etc.) related to each dynamic image generated by the radiographic imaging device 10. Furthermore, the storage unit 32 stores analysis results in association with the dynamic image.

[0069] The operation unit 33 is an operation device such as a keyboard equipped with cursor keys, numeric input keys, and various function keys, a pointing device such as a mouse or a trackball, and a touch panel. The operation unit 33 generates instruction signals based on input by the operator and outputs them to the control unit 31. The operation unit 33 may also be equipped with a touch panel on the display screen of the display unit 34, in which case the operation unit 33 outputs instruction signals input via the touch panel to the control unit 31.

[0070] The display unit 34 is configured with a display device such as a CRT, a liquid crystal display, an organic EL display, etc. In accordance with instructions of a display signal input from the control unit 31, the display unit 34 displays input instructions from the operation unit 33, image data (dynamic images, etc.) generated by the radiographic image capturing device 10, etc.

[0071] The communication unit 35 transmits and receives data to and from the radiation imaging control device 20, the image management device 40, and the like.

[0072] [Breath-holding failure detection process] Fig. 5 is a flowchart illustrating the inadequate breath-holding determination process performed by the radiation imaging control device 20. The program for the inadequate breath-holding determination process described below is included in the dynamic imaging program executed by the control unit 21. Fig. 6 is a diagram illustrating a first region of interest from which a periodic signal waveform is acquired and a second region of interest from which a lung field signal waveform is acquired in one frame of a dynamic image captured by the radiation imaging device 10 and the radiation imaging control device 20.

[0073] (Step S11) The radiographic imaging device 10 and the radiographic imaging control device 20 perform dynamic imaging, which includes a breath-hold instruction as an imaging condition, on the patient M to be imaged. During dynamic imaging, the radiographic imaging control device 20 instructs the patient M to hold their breath, for example, by auto-voice using the audio output unit 16.

[0074] For example, when examining pulmonary blood flow, that is, when executing the blood flow analysis mode, it is desirable to hold one's breath during dynamic imaging, and the doctor or operator sets imaging conditions including a breath-hold instruction as imaging conditions. These imaging conditions are transmitted as examination order information, together with examination information, patient information, imaging information, etc., from the radiation information terminal 60, for example, to the radiation imaging control device 20.

[0075] (Step S12) The radiography control device 20 (waveform acquisition unit 211) acquires a periodic signal waveform and a lung field signal waveform from a dynamic image acquired by dynamic radiography.

[0076] Here, the control unit 21 of the radiography control device 20 first recognizes the lung field region in each frame of the dynamic image, for example, by edge detection processing of the lung field, and sets the lung fields R21L, R21R, diaphragm R22L, R22R, etc. shown in Fig. 6. Thereafter, the control unit 21 recognizes the heart region in each frame of the dynamic image, for example, by template matching processing, and sets the apex R11, right ventricle R12, aorta R13, etc. shown in Fig. 6.

[0077] A periodic signal waveform is a waveform synchronized with the heartbeat. Therefore, the waveform acquiring unit 211 of the control unit 21 targets a region related to the heart, such as the apex R11, the right ventricle R12, the aorta R13, etc. shown in Fig. 6, as a first region of interest from which to acquire a periodic signal waveform. The waveform acquiring unit 211 acquires the periodic signal waveform based on changes in signal intensity of the apex R11, the right ventricle R12, the aorta R13, etc.

[0078] For example, the graph shown in the lower part of Fig. 6 is a periodic signal waveform acquired based on changes in signal intensity at the apex R11 of the heart, which is the first region of interest. Here, a periodic signal waveform based on changes in signal intensity at the apex R11 of the heart is shown as an example, but similar periodic signal waveforms can also be acquired from the right ventricle R12 or the aorta R13.

[0079] Furthermore, the lung field signal waveform is a waveform related to the lung field. Therefore, the waveform acquisition unit 211 targets regions related to the lung field, such as the lung fields R21L and R21R and the diaphragm R22L and R22R shown in Fig. 6, as the second region of interest from which to acquire the lung field signal waveform. Although not shown in Fig. 6, the ribs may also be used as the second region of interest. The waveform acquisition unit 211 acquires the lung field signal waveform based on changes in the area and transmittance of the lung fields R21L and R21R, changes in the position and shape of the diaphragms R22L and R22R, and changes in the position of the ribs.

[0080] For example, the graph shown in the upper part of Fig. 6 is a lung field signal waveform acquired based on changes in the area of ​​lung field R21L, for example, with lung field R21L as the second region of interest. Here, a lung field signal waveform based on changes in the area of ​​lung field R21L is shown as an example, but a similar lung field signal waveform can also be acquired for lung field R21R. Furthermore, a similar lung field signal waveform can be acquired based on changes in the transmittance of lung fields R21L and R21R, changes in the position and shape of diaphragms R22L and R22R, and changes in the position of the ribs.

[0081] When the breath-holding state is maintained, the lung field signal waveform mainly contains periodic signal components accompanying the heartbeat, but if, for example, the breath-holding state cannot be maintained and even a slight breath is taken, the lung field signal waveform contains random signal components, i.e., non-periodic signal components. Therefore, as will be described below, by comparing the periodic signal waveform with the lung field signal waveform, it is possible to accurately determine whether breath-holding is inadequate, and the reliability of the determination can be improved.

[0082] (Step S13) The radiography control device 20 (determining unit 212) compares the periodic signal waveform with the lung field signal waveform, and obtains the comparison result, for example, the similarity.

[0083] Here, Fig. 7A is a graph comparing, on the time axis, periodic signal waveforms and lung field signal waveforms acquired from the first and second regions of interest shown in Fig. 6, and showing a case where there is no poor breath-holding. Also, Fig. 7B is a graph comparing, on the time axis, periodic signal waveforms and lung field signal waveforms acquired from the first and second regions of interest shown in Fig. 6, and showing a case where there is poor breath-holding. Here, as an example, the first region of interest from which periodic signal waveforms are acquired is the apex of the heart R11, and the second region of interest from which lung field signal waveforms are acquired is the lung field R21L (see Fig. 6).

[0084] When there is no poor breath-holding, random signal components due to poor breath-holding are not included in the lung field signal waveform, so the periodic signal waveform and the lung field signal waveform are similar (have similar shapes), as shown in Figure 7A. On the other hand, when there is poor breath-holding, random signal components due to poor breath-holding are included in the lung field signal waveform, so changes in signal intensity due to poor breath-holding appear in the lung field signal waveform, as shown in Figure 7B, and the periodic signal waveform and the lung field signal waveform are no longer similar (have similar shapes).

[0085] Therefore, the determination unit 212 of the control unit 21 evaluates the similarity of the pulmonary field signal waveform to the periodic signal waveform, for example, and obtains the waveform similarity as a comparison result between the periodic signal waveform and the pulmonary field signal waveform.

[0086] Although the similarity of the pulmonary field signal waveform to the periodic signal waveform is evaluated here, it is not limited to the waveform, and the similarity of the frequency spectrum may also be evaluated. Here, Fig. 8 is a graph showing the frequency spectrum obtained by Fourier transforming the periodic signal waveform and the pulmonary field signal waveform.

[0087] For example, the determination unit 212 may perform a Fourier transform on the periodic signal waveform and the pulmonary field signal waveform to obtain their respective frequency spectra, as shown in Fig. 8. Then, the determination unit 212 may evaluate the similarity of the frequency spectrum of the pulmonary field signal waveform to the frequency spectrum of the periodic signal waveform, and obtain the similarity of the frequency spectra as a comparison result between the periodic signal waveform and the pulmonary field signal waveform.

[0088] Furthermore, evaluation is not limited to the above-described similarity, and may be based on, for example, the difference between waveforms or spectra.

[0089] (Step S14) The radiation imaging control device 20 (determination unit 212) determines whether the acquired similarity is equal to or greater than a predetermined similarity, and if the similarity is equal to or greater than the predetermined similarity (YES), proceeds to step S15, and if the similarity is less than the predetermined similarity (NO), proceeds to step S16.

[0090] (Step S15) If the similarity is equal to or greater than a predetermined similarity (YES in step S14), the radiation imaging control apparatus 20 (determining unit 212) determines that there is no inadequate breath-holding.

[0091] (Step S16) If the similarity is less than the predetermined similarity (NO in step S14), the radiation imaging control apparatus 20 (determining unit 212) determines that there is poor breath-holding.

[0092] When determining the similarity as described above, the control unit 21 may display the compared periodic signal waveform and lung field signal waveform, or the frequency spectrum of the compared periodic signal waveform and lung field signal waveform, together with the determination result on the display unit 24, or may store them in the memory unit 22.

[0093] After the above-described poor breath-holding determination process is completed, if the control unit 21 determines that poor breath-holding has occurred, it may display, for example, "Do you want to retake the image?" on the display unit 24. Furthermore, the control unit 21 may determine, for example, whether the cause is breathing or body movement based on a non-periodic signal waveform included in the lung field signal waveform. Whether the cause is breathing or body movement can be determined, for example, by selecting a region of interest where body movement is likely to occur.

[0094] On the other hand, if the control unit 21 determines that there is no inadequate breath-holding, it transmits the acquired dynamic image together with the determination result to the radiation image analysis device 30, the image management device 40, or the like.

[0095] The radiographic image analyzer 30 analyzes the dynamic image transmitted from the radiography control device 20, and in the case of a blood flow analysis mode, for example, visualizes the blood flow in the lung field as the analysis result.

[0096] The analysis results obtained by the radiation image analysis device 30 are then transmitted to the image management device 40 together with the above-mentioned determination results and dynamic images, and can be viewed by a doctor or the like from the client terminal 50, for example.

[0097] A doctor viewing the analysis results from client terminal 50 can confirm from the above determination results that no poor breath-holding occurred during dynamic imaging. In this case, the analysis results are based on dynamic images captured without poor breath-holding, so the reliability of the analysis is high, and the doctor can make a correct diagnosis based on the analysis results.

[0098] As described above, the radiography control device 20 includes the waveform acquisition unit 211 and the determination unit 212. The waveform acquisition unit 211 acquires a lung field signal waveform related to the lung field and a periodic signal waveform synchronized with the heartbeat from dynamic images acquired during radiography whose imaging conditions include a breath-holding instruction. The determination unit 212 determines whether poor breath-holding has occurred during radiography based on a comparison result between the acquired lung field signal waveform and the periodic signal waveform.

[0099] The radiography control device 20 compares the lung field signal waveform with the periodic signal waveform and determines whether or not breath-holding is inadequate based on, for example, the degree of similarity between them. This allows for accurate determination of whether breath-holding is inadequate, improving the reliability of the determination.

[0100] Furthermore, since the radiography control device 20 accurately determines whether breath-holding is improper, the radiography image analysis device 30 can correctly perform dynamic analysis on dynamic images that are determined not to have improper breath-holding, thereby obtaining correct analysis results without generating artifacts.

[0101] Furthermore, the radiation imaging control device 20 performs the process of determining whether breath-holding is poor, so that the determination of whether breath-holding is poor can be made immediately after dynamic imaging. If the radiation imaging control device 20 determines that breath-holding is poor, consent for re-imaging is obtained from the patient M, and by presenting the determination result to the patient M, re-imaging can be carried out smoothly. At that time, if the cause of the poor breath-holding (for example, breathing or body movement) has been identified, the cause can be taken into consideration when re-imaging.

[0102] The above-described embodiments are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be carried out in various forms without departing from the gist or main features thereof.

[0103] For example, in the above embodiment, the radiography control device 20 performs the determination process for inadequate breath-holding during dynamic radiography, but the determination process for inadequate breath-holding may also be performed during dynamic analysis. In this case, the determination process for inadequate breath-holding is performed by the radiographic image analyzer 30. [Explanation of symbols]

[0104] 1. Radiation image processing system 10 Radiation imaging device 11. Imaging control unit 12 Radiation irradiation unit 13 Photo stand 14 Radiation detection unit 15 Display section 16 Audio output section 20 Radiography control device 21 Control section 22 Memory section 23 Control section 24 Display 25 Communications Department 26 Bus 30 Radiation image analysis device 31 Control Unit 32 Storage section 33 Operation section 34 Display section 35 Communications Department 36 Bus 40 Image management device 50 client terminals 60 Radiation Information Terminal 111 Setting information acquisition unit 112 Shooting condition determination unit 113 Image Generation Unit 114 Storage section 211 Waveform acquisition section 212 Judgment section 311 Image Acquisition Unit 312 Analysis Department

Claims

1. a waveform acquisition unit that acquires a lung field signal waveform and a periodic signal waveform synchronized with a heartbeat from a dynamic image acquired in a radiographic dynamic imaging that includes a breath-hold instruction as an imaging condition; a determination unit that determines whether poor breath-holding has occurred during the radiographic dynamic imaging based on a comparison result between the acquired lung field signal waveform and the acquired periodic signal waveform; Equipped with Dynamic imaging device.

2. the determination unit compares the lung field signal waveform with the periodic signal waveform on a time axis to obtain the comparison result; The dynamic imaging apparatus according to claim 1.

3. the comparison result is a similarity of the lung field signal waveform to the periodic signal waveform; The dynamic imaging apparatus according to claim 2.

4. the determination unit compares the frequency spectrum of the lung field signal waveform with the frequency spectrum of the periodic signal waveform to obtain the comparison result; The dynamic imaging apparatus according to claim 1.

5. the comparison result is a similarity between the frequency spectrum of the lung field signal waveform and the frequency spectrum of the periodic signal waveform. The dynamic imaging apparatus according to claim 4.

6. the waveform acquisition unit acquires the lung field signal waveform based on at least one of a change in the position of the diaphragm, a change in the shape of the diaphragm, a change in the area of ​​the lung field, a change in the transmittance of the lung field, and a change in the position of the ribs in the dynamic image. The dynamic imaging apparatus according to claim 1.

7. the waveform acquisition unit acquires the periodic signal waveform based on at least one of a change in signal intensity of the apex of the heart, a change in signal intensity of the right heart, and a change in signal intensity of the aorta in the dynamic image. The dynamic imaging apparatus according to claim 1.

8. The computer of the dynamic radiography device A process of acquiring a lung field signal waveform and a periodic signal waveform synchronized with a heartbeat from a dynamic image acquired in a radiographic dynamic imaging including a breath-hold instruction as an imaging condition; a process of determining whether poor breath-holding has occurred during the radiographic dynamic imaging based on a comparison result between the acquired lung field signal waveform and the acquired periodic signal waveform; Execute Poor breath-holding assessment program.

Images