Motion image processing device, motion image processing method, and program

Abstract

The present invention provides a motion image processing device, etc., that can acquire motion images suitable for motion analysis processing. [Solution] The motion analysis device comprises: a first generation unit that generates dose waveforms including blood flow fluctuations and respiratory fluctuations in the region of interest of each frame image constituting a motion image obtained by motion imaging with radiation; an extraction unit that extracts frame waveforms containing random body movement fluctuations different from blood flow fluctuations and respiratory fluctuations from the dose waveforms generated by the first generation unit; and a second generation unit that generates information indicating that the waveform information extracted by the extraction unit is a motion image unsuitable for motion analysis.

Description

Technical Field

[0001] The present invention relates to a dynamic image processing apparatus, a dynamic image processing method, and a program.

Background Art

[0002] Clinical research on dynamic analysis using X-ray dynamic images has been progressing, and dynamic analysis is being utilized in the examination of various diseases. For example, a dynamic analysis theory for analyzing blood flow such as pulmonary blood flow and cardiac blood flow using X-ray dynamic images has been developed. Patent Document 1 describes a dynamic image analysis apparatus that generates information regarding pulmonary valve regurgitation based on dynamic images of a region of interest such as the pulmonary artery or the heart.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, noise may be included in the dynamic image due to unpredictable movements of the patient, body movement variations due to coughing, etc., respiratory variations due to breathing, arrhythmia, etc. However, with the conventional technology, although information such as pulmonary valve regurgitation can be generated based on the dynamic image, noise due to body movement variations etc. included in the dynamic image cannot be extracted. When performing dynamic analysis processing using a dynamic image including noise due to body movement variations etc., there is a problem that appropriate analysis results cannot be obtained.

[0005] Therefore, an object of the present invention is to provide a dynamic image processing apparatus, a dynamic image processing method, and a program that can acquire a dynamic image appropriate for dynamic analysis processing in order to solve the above problems.

Means for Solving the Problems

[0006] The motion image processing apparatus according to the present invention is A first generation unit generates waveform information including blood flow fluctuations and respiratory fluctuations in a predetermined region of each frame image constituting a dynamic image obtained by dynamic imaging using radiation, An extraction unit extracts waveform information from the waveform information generated by the first generation unit that includes dose fluctuations different from the blood flow fluctuations and respiratory fluctuations, It is equipped with.

[0007] The motion image processing method according to the present invention is A generation step that generates waveform information including blood flow fluctuations and respiratory fluctuations in a predetermined region of each frame image constituting a dynamic image obtained by dynamic imaging using radiation, Extraction step of extracting waveform information from the generated waveform information that includes dose fluctuations different from the blood flow fluctuations and respiratory fluctuations, It holds.

[0008] The program according to the present invention is Computers, A generation unit that generates waveform information including blood flow fluctuations and respiratory fluctuations in a predetermined region of each frame image constituting a dynamic image obtained by dynamic imaging using radiation. An extraction unit extracts waveform information from the waveform information generated by the generation unit that includes dose fluctuations different from the blood flow fluctuations and respiratory fluctuations. To make it function as such. [Effects of the Invention]

[0009] According to the present invention, waveform information including noise due to fluctuations in patient body movement can be extracted from waveform information, so that a predetermined motion analysis can be performed using appropriate motion images. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows an example of a schematic configuration of the image acquisition system according to this embodiment. [Figure 2]This figure shows frame images that constitute a dynamic image with a defined region of interest according to this embodiment. [Figure 3] This is a dose waveform showing the change in the signal value of a pixel in the region of interest of the dynamic image according to this embodiment. [Figure 4] This flowchart shows an example of the operation of the motion analysis device when extracting noise due to body motion fluctuations from waveform information showing dose fluctuations in the region of interest of a motion image according to this embodiment. [Figure 5] This flowchart shows an example of the operation of the control unit during the first processing according to this embodiment. [Figure 6] This figure shows the dose waveform for which the reference frame waveform of this embodiment has been set. [Figure 7] This figure shows the dose waveform for which the comparison frame waveform of this embodiment has been set. [Figure 8] This flowchart shows an example of the operation of the control unit during the second process according to this embodiment. [Figure 9] This figure shows the dose waveforms in the region of interest of a dynamic image, with the first frame waveform, second frame waveform, third frame waveform, and fourth frame waveform set for each respiratory cycle according to this embodiment. [Modes for carrying out the invention]

[0011] A dynamic image processing apparatus, a dynamic image processing method, and a program according to a preferred embodiment of this disclosure will be described in detail below with reference to the attached drawings.

[0012] [Example configuration of image acquisition system 100] Figure 1 shows an example of a schematic configuration of the image acquisition system 100 according to this embodiment. The image acquisition system 100 comprises an imaging device 1, a console 2, and a motion analysis device 3, which is an example of a motion image processing device. The imaging device 1, console 2, and motion analysis device 3 are connected to each other via a network N, such as a LAN (Local Area Network). The communication method of the network N may be wired communication or wireless communication.

[0013] The imaging device 1 captures a dynamic image of a predetermined imaging region of a subject. The console 2 controls the radiation imaging by the imaging device 1 and also controls the reading operation of the radiation image by the imaging device 1. The dynamic analysis device 3 performs a predetermined dynamic analysis process on the dynamic image transmitted from the console 2 or the like. In the present embodiment, the dynamic analysis device 3 extracts a frame waveform composed of a plurality of frame images including noise due to body movement variations of the subject M in a predetermined region of the dynamic image before performing the dynamic analysis process. Each device constituting the image capture system 100 conforms to the DICOM (Digital Image and Communications in Medicine) standard, and the communication between the devices is performed according to the DICOM standard.

[0014] [Configuration example of imaging device 1] The imaging device 1 can dynamically capture, for example, the morphological changes of the lungs during inhalation and exhalation and the pulsation of the heart associated with respiratory movements. Dynamic imaging refers to obtaining a series of images of the subject M by repeatedly irradiating the subject M with radiation such as X-rays in a pulsed manner at a predetermined time interval in response to a single imaging operation. Repeatedly irradiating the radiation in a pulsed manner at a predetermined time interval is called pulsed irradiation. Alternatively, dynamic imaging refers to obtaining a series of images of the subject M by continuously irradiating the subject M at a low dose rate without interruption in response to a single imaging operation. Continuously irradiating the radiation without interruption is called continuous irradiation. A series of images obtained by dynamic imaging is called a dynamic image. Also, each of all the images constituting the dynamic image is called a frame image. Here, dynamic imaging includes video imaging, but does not include those that capture still images while displaying a video. Also, the dynamic image includes videos, but does not include images obtained by capturing still images while displaying a video.

[0015] 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 14. The radiation irradiation control device 12 and the reading control device 14 are connected via a communication cable or the like, and synchronize the radiation irradiation operation and the image reading operation by exchanging synchronization signals with each other. Note that the radiation detection unit 13 and the reading control device 14 may be integrally configured.

[0016] The radiation source 11 is disposed at a position facing the radiation detection unit 13 with the subject M interposed therebetween. The radiation source 11 irradiates the subject M with radiation such as X-rays according to the control of the radiation irradiation control device 12. The radiation irradiation control device 12 is connected to the console 2. The radiation irradiation control device 12 controls the radiation source 11 based on the radiation irradiation conditions input from the console 2 to perform radiation imaging. The radiation irradiation conditions input from the console 2 are, for example, pulse rate, pulse width, pulse interval, number of imaging frames per imaging, value of X-ray tube current, value of X-ray tube voltage, additional filter type, etc. The pulse rate is the number of radiation irradiations per second and is consistent with the frame rate described later. 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 is consistent with the frame interval described later.

[0017] The radiation detection unit 13 is composed of a semiconductor image sensor such as an FPD (Flat Panel Detector). The FPD has a substrate formed of glass or the like. A plurality of detection elements including pixels and the like are arranged in a matrix at predetermined positions on the substrate. The plurality of detection elements detect the radiation irradiated from the radiation source 11 and at least transmitted through the subject M according to its intensity, convert the detected radiation into an electrical signal, and accumulate it. Each pixel has a switching unit such as a TFT (Thin Film Transistor). The FPD may be of an indirect conversion type or a direct conversion type, and either type may be used. The indirect conversion type is a method of converting radiation into an electrical signal by a photoelectric conversion element via a scintillator. The direct conversion type is a method of directly converting radiation into an electrical signal.

[0018] The reading control device 14 is connected to the console 2. The reading control device 14 controls the switching unit of each pixel of the radiation detection unit 13 based on the image reading conditions input from the console 2. The reading control device 14 switches the reading of the electrical signals accumulated in each pixel of the radiation detection unit 13, and acquires image data by reading the electrical signals accumulated in the radiation detection unit 13. The image data is either a frame image of a moving image or a still image. If a structure exists between the radiation source 11 and the radiation detection unit 13, the amount of radiation reaching the radiation detection unit 13 decreases due to the structure. In this case, the signal value of each pixel of the image data changes according to the structure of the subject M. The signal value includes the pixel value, density value, etc. The reading control device 14 outputs the acquired moving image or still image to the console 2. The image reading conditions are, for example, the frame rate, frame interval, pixel size, image size, etc. The frame rate is the number of frames acquired per second and is the same as the pulse rate. The frame interval is the time from the start of one frame image acquisition operation to the start of the next frame image acquisition operation, and it coincides with the pulse interval.

[0019] [Example configuration for Console 2] Console 2 is comprised of a computer, such as a personal computer or workstation. As shown in Figure 1, Console 2 includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25. The control unit 21, storage unit 22, operation unit 23, display unit 24, and communication unit 25 are connected by wiring such as a bus 26.

[0020] The control unit 21 includes a CPU (Central Processing Unit), RAM (Random Access Memory), etc. In response to the operation of the operation unit 23, the CPU 21 reads the system program and various processing programs stored in the memory unit 22, loads them into the RAM, and executes various processes according to the loaded programs. The control unit 21 centrally controls the operation of each part of the console 2, the radiation irradiation operation and reading operation of the imaging device 1.

[0021] The storage unit 22 is a non-volatile semiconductor memory, hard disk, etc. The storage unit 22 stores data such as various programs executed by the control unit 21, parameters necessary for executing processing by the programs, and processing results. The various programs are stored in the form of readable program code. The control unit 21 sequentially executes operations according to the program code.

[0022] The operation unit 23 includes a keyboard, mouse, etc. The operation unit 23 may also be a touch panel combined with the display screen of the display unit 24. The operation unit 23 receives various instructions from the user's input and outputs instruction signals corresponding to the received instructions to the control unit 21.

[0023] The display unit 24 is a monitor such as an LCD (Liquid Crystal Display). The display unit 24 displays input instructions and data from the operation unit 23 according to the instructions of the display signals input from the control unit 21.

[0024] The communication unit 25 includes a LAN adapter, modem, etc. The communication unit 25 transmits and receives signals, data, etc., to and from the imaging device 1, motion analysis device 3, etc., which are connected to the network N.

[0025] [Example configuration of Dynamic Analysis System 3] The dynamic analysis device 3 is used as a diagnostic support device to assist physicians in their diagnoses. The dynamic analysis device 3 is composed of a computer, such as a personal computer or workstation. As shown in Figure 1, the dynamic analysis device 3 comprises a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, and a communication unit 35. The control unit 31, storage unit 32, operation unit 33, display unit 34, and communication unit 35 are connected by wiring on a bus 36.

[0026] The control unit 31 includes a CPU, RAM, etc. The CPU reads various programs P, such as system programs, stored in the memory unit 32 in response to operations on the operation unit 33, expands them into RAM, and executes various processes according to the expanded programs. The control unit 31 centrally controls the operation of each part of the dynamic analysis device 3.

[0027] The storage unit 32 includes non-volatile semiconductor memory, a hard disk, etc. The storage unit 32 stores data such as various programs P executed by the control unit 31, parameters necessary for executing the processing by programs P, and processing results. The various programs P are stored in the form of readable program code. The control unit 31 sequentially executes operations according to the program code.

[0028] The operation unit 33 includes a keyboard, mouse, etc. The operation unit 33 may also be a touch panel combined with the display screen of the display unit 24. The operation unit 33 receives various instructions from the user's input and outputs instruction signals corresponding to the received instructions to the control unit 31.

[0029] The display unit 34 has a monitor such as an LCD. The display unit 34 displays various information according to the instructions of the display signals input from the control unit 31. The communication unit 35 has a LAN adapter, modem, etc. The communication unit 35 sends and receives signals, data, etc. to and from the console 2, etc., which is connected to the network N.

[0030] The control unit 31 of the dynamic analysis device 3 functions as a first generation unit, an extraction unit, a second generation unit, and a setting unit. The processor of the control unit 31 realizes the functions of the first generation unit, extraction unit, second generation unit, and setting unit by executing a program P stored in the memory unit 32, etc. The first generation unit generates dose waveforms (waveform information) including blood flow fluctuations and respiratory fluctuations in the region of interest of each frame image constituting the dynamic image obtained by dynamic imaging with radiation. The region of interest is called ROI (Region of Interest). The dose waveform is generated based on the signal value of each pixel in the region of interest of each frame of the dynamic image. Figure 2 is a diagram showing a frame image G constituting a dynamic image in which a region of interest R has been set according to this embodiment. The imaging site is the front of the chest. In this embodiment, for example, the region of interest R is set in the region including the pulmonary artery in the lung field region of frame image G. This allows users such as doctors to diagnose pulmonary artery regurgitation.

[0031] The extraction unit extracts frame waveforms from the dose waveforms generated by the first generation unit that contain dose fluctuations different from blood flow fluctuations and respiratory fluctuations. Specifically, the extraction unit compares a reference frame waveform in the waveform information with other frame waveforms that differ from this reference frame waveform information. Hereinafter, the other frame waveforms will be referred to as comparison frame waveforms. The reference frame waveform and comparison frame waveform are multiple frame images, each consisting of the same number of frames. If the reference frame waveform and the comparison frame waveform do not match, the extraction unit extracts the comparison frame waveform as a frame image containing noise such as body motion fluctuations. Random body motion fluctuations include, for example, unpredictable movements of the patient, fluctuations due to coughing, etc. The second generation unit generates information indicating that the comparison frame waveform containing body motion fluctuations extracted by the extraction unit is a dynamic image unsuitable for dynamic analysis. The setting unit sets the reference frame waveform, etc., based on the type of dynamic analysis.

[0032] [Regarding the dose waveform in the region of interest R of dynamic images] Figure 3 shows a dose waveform illustrating the change in pixel signal values ​​in the region of interest R of the dynamic image according to this embodiment. In Figure 3, the vertical axis represents the pixel signal value, and the horizontal axis represents time. The dose waveform is, for example, a graph obtained by averaging the signal values ​​of each pixel in the region of interest R. The dose waveform includes at least respiratory fluctuations associated with inhalation and exhalation in the subject M, and blood flow fluctuations associated with the beating of the heart (heartbeat).

[0033] Let's explain respiratory variability. During the inspiratory time from maximum expiratory to maximum inhalation, air flows into the lung field. Maximum expiratory position is the moment when the maximum amount of air has been exhaled from the lung field. Maximum inspiratory position is the moment when the maximum amount of air has been taken into the lung field. In this case, the amount of X-ray transmission in the lung field region increases, and the signal value of the pixels in the region of interest R increases from the maximum expiratory position to the maximum inspiratory position. On the other hand, during the expiratory period from maximum inhalation to maximum expiratory, air flows out of the lung field. In this case, the amount of X-ray transmission in the lung field region decreases, and the signal value of the pixels in the region of interest R of the dynamic image decreases from maximum inhalation to maximum expiratory position. Therefore, as shown in Figure 3, respiratory variability is a waveform that gradually shifts between the maximum expiratory position and the maximum inspiratory position in accordance with the patient's inhalation and exhalation.

[0034] Next, let's discuss blood flow fluctuations. When the heart is in ventricular diastole, less blood flows into the lung field. In this case, the amount of X-ray transmission in the pulmonary artery increases, and the signal value of each pixel in the region of interest R of the dynamic image also increases. On the other hand, when the heart is in ventricular systole, a large amount of blood flows from the heart into the lung field via the pulmonary artery. Therefore, the amount of X-ray transmission in the lung field decreases, and the signal value of each pixel in the region of interest R of the dynamic image also decreases. As a result, blood flow fluctuations appear as a waveform that repeatedly increases and decreases in signal value according to the heartbeat, as shown in Figure 3, and are superimposed on the waveform of respiratory fluctuations.

[0035] During dynamic imaging, random body movement fluctuations may occur due to unpredictable movements by the patient, coughing, poor breath-holding, etc. For example, if random body movement fluctuations occur around time T1 as shown in Figure 3, the waveform around time T1 will be significantly different from the waveform at the maximum inspiratory position where respiratory fluctuations are most stable. If the waveform at the time when random body movement fluctuations occur is used in the dynamic analysis process, it may not be possible to obtain appropriate analysis results. Therefore, in this embodiment, the frame waveform at the time when random body movement fluctuations occur is extracted from the dose waveform, and information is generated indicating that the extracted frame waveform is unsuitable for the dynamic analysis process.

[0036] [Example of operation of image capture system 100] Figure 4 is a flowchart illustrating an example of the operation of the motion analysis device 3 when extracting noise due to motion fluctuations from waveform information showing dose fluctuations in the region of interest R of a motion image according to this embodiment. The control unit 31 executes the program P stored in the storage unit 32 to realize the processing including the generation step and extraction step shown in Figure 4.

[0037] First, the operation of the imaging device 1 and console 2 during dynamic imaging will be explained. The control unit 21 of console 2 sets the radiation irradiation conditions in the radiation irradiation control device 12 and the image reading conditions in the reading control device 14. Next, the control unit 21 outputs a command to start capturing dynamic images to the radiation irradiation control device 12 and the reading control device 14. The radiation source 11 of imaging device 1 irradiates the subject M with radiation at the pulse interval set in the radiation irradiation control device 12. The reading control device 14 outputs the image data acquired by the radiation detection unit 13 to console 2.

[0038] The control unit 21 of console 2 stores each frame image of the motion images contained in the image data transmitted from the imaging device 1 in the storage unit 22, associating it with the frame number indicating the order of acquisition. Next, the control unit 21 displays the acquired motion images on the display unit 24. The user, such as a radiologist, checks whether the images are suitable for diagnosis. Based on the user's confirmation instructions, the control unit 21 adds patient information and examination information to the motion images acquired by motion imaging and transmits these motion images to the motion analysis device 3.

[0039] As shown in Figure 4, the control unit 31 of the motion analysis device 3 acquires motion images of a predetermined imaging area from the console 2 via the communication unit 35 (step S10). For example, the imaging area is the front of the chest as shown in Figure 2. The motion image consists of multiple frame images. The control unit 31 stores the acquired motion image in the storage unit 32.

[0040] The control unit 31 sets a region of interest R in the frame image of the acquired dynamic image (step S11). For example, as shown in Figure 2, the control unit 31 sets the region of interest R near the pulmonary artery in the lung field. The area near the pulmonary artery is a part with a lot of blood flow and appears whitish in the dynamic image. Therefore, the control unit 31 can automatically set the region of interest R as the area in the lung field of the dynamic image where there are many pixels with high brightness values. Note that the setting of the region of interest R is not limited to automatic setting by the control unit 31. A user such as a radiologist may also set the region of interest R manually. In this case, for example, the display unit 34 may display an image of the lung field that clearly shows the contrast between the part that appears white due to blood flow and the other parts. The user can set the region of interest R by selecting the area near the pulmonary artery using the operation unit 33 in the image displayed on the display unit 34.

[0041] The control unit 31 generates a dose waveform that shows the change in the signal value of each pixel in the region of interest R for all the set frame images (step S12). Specifically, as shown in Figure 3, the control unit 31 generates a dose waveform in the region of interest R of each frame image of the dynamic image that includes respiratory fluctuations associated with inhalation and exhalation, and blood flow fluctuations associated with the beating of the heart (heartbeat).

[0042] For dose waveforms showing changes in generated signal values, one of the first, second, and third processes is executed according to the analysis purpose before the dynamic analysis process (step S13). For example, the user may select a process suitable for the purpose of analyzing the dynamic image from the items of the first to third processes displayed on the screen of the display unit 34 by operating the operation unit 33. Alternatively, the control unit 31 may automatically acquire a process suitable for the purpose of analyzing the acquired dynamic image based on information such as the shooting area and region of interest. Here, the first process is a process for extracting a frame waveform that includes fluctuations corresponding to random body movements from the dose waveform. The second process is a process for extracting a period that is less affected by periodic noise from the dose waveform. The third process is a process for extracting a frame image that includes body movements based on a reference frame image when the region of interest R is the entire image.

[0043] If the process branches to the first process in step S13, the control unit 31 executes the first process on the acquired dynamic image (step S14). In this case, the control unit 31 proceeds to the subroutine shown in Figure 5. Figure 5 is a flowchart showing an example of the operation of the control unit 31 during the first process according to this embodiment. As shown in Figure 5, the control unit 31 sets a reference frame waveform in the dose waveform of the region of interest in each frame image of the dynamic image (step S100). Figure 6 is a diagram showing the dose waveform with the reference frame waveform FS set according to this embodiment. The reference frame waveform FS may be composed of, for example, multiple frame images at and around the maximum expiratory position, or multiple frame images at and around the maximum inspiratory position. This is because the frame images at the maximum expiratory position and maximum inspiratory position are least affected by respiratory fluctuations, and when used in dynamic analysis processing, appropriate dynamic analysis results can be obtained. In this embodiment, the reference frame waveform FS is set using multiple frame images at and around the maximum expiratory position. The reference frame waveform FS is set to include, for example, two heartbeats' worth of peaks due to blood flow fluctuations. In Figure 6, the range containing the reference frame waveform FS is indicated by a dotted-dotted rectangular frame.

[0044] The control unit 31 may set a reference frame waveform FS according to the type of dynamic analysis to be performed. This is because the content of the dynamic analysis differs depending on the type of dynamic analysis, and the extent to which noise such as body motion fluctuations affects each dynamic analysis also differs. The type of dynamic analysis can be determined, for example, based on the shooting conditions such as the shooting area. The shooting conditions such as the shooting area are set based on order information transmitted from the RIS, etc.

[0045] The control unit 31 sets a comparison frame waveform to be compared with the reference frame waveform FS in the dose waveform (step S101). Figure 7 shows a dose waveform in which the comparison frame waveform Fa, etc., according to this embodiment has been set. The control unit 31 may, for example, set the comparison frame waveform Fa, etc., in order by moving the rectangular frame of the reference frame waveform FS along the time direction of the dose waveform. Specifically, if the reference frame waveform FS is 50 to 60 frames, the comparison frame waveform Fa, etc., can be set in order by moving it every 5 frames, for example. In this case, the comparison frame waveform Fa is 55 to 65 frames. Note that the number of frames to move is not limited to 5 frames, and may be, for example, 1 frame. In Figure 7, the range including the comparison frame waveforms Fa, Fb, etc., is shown by a dashed rectangular frame. Note that the number of comparison frame waveforms to set is not limited to the number shown in Figure 7. Alternatively, the user may manually set the reference frame waveform FS, comparison frame waveform Fa, etc., while checking the screen of the display unit 34.

[0046] The control unit 31 sequentially determines whether the reference frame waveform FS and the comparison frame waveform Fa, etc., match (step S102). Specifically, the control unit 31 compares the reference frame waveform FS and the comparison frame waveform Fa, etc., and determines the degree of similarity between these frame waveforms. The control unit 31 may determine the degree of similarity with the comparison frame waveform Fa, etc., using, for example, the number of peaks or signal values ​​of the reference frame waveform FS. For example, when the control unit 31 determines the degree of similarity using signal values, it can determine that the similarity between the reference frame waveform FS and the comparison frame waveform is high when the amplitude of the comparison frame waveform is in the range of 90 to 110% with the amplitude of the reference frame waveform FS being 100%. Furthermore, the conditions for determining similarity may be other conditions besides the number of peaks or signal value width of the reference frame waveform FS, such as a cross-correlation function that utilizes the entire signal value waveform.

[0047] Specifically, when the comparison target is the comparison frame waveform Fa with the reference frame waveform FS, the similarity is determined as follows. As shown in Figure 7, the number of peaks in the reference frame waveform FS and the number of peaks in the comparison frame waveform Fa are both 2 within the rectangular frame. Therefore, the control unit 31 can determine that the similarity between the reference frame waveform FS and the comparison frame waveform Fa is high. In this case, the control unit 31 determines that the reference frame waveform FS and the comparison frame waveform Fa are identical and proceeds to step S104.

[0048] When the comparison target is the comparison frame waveform Fb with the reference frame waveform FS, the similarity is determined as follows. As shown in Figure 7, the reference frame waveform FS has 2 peaks within the rectangular frame, while the number of peaks in the comparison frame waveform Fb is unknown within the rectangular frame. Therefore, the control unit 31 can determine that the similarity between the reference frame waveform FS and the comparison frame waveform Fb is low. The control unit 31 extracts the comparison frame waveform Fb as a frame waveform that includes the patient's body movements, etc. In this case, the control unit 31 determines that the reference frame waveform FS and the comparison frame waveform Fa do not match and proceeds to step S103.

[0049] The control unit 31 generates analysis-unsuitable information for comparison frame waveforms Fb, etc., that do not match the reference frame waveform FS, indicating that they are unsuitable for dynamic analysis processing (step S103). Specifically, when the dynamic image consists of 100 frames, and the 80th to 90th frames contain noise due to body movement fluctuations, the processing is performed as follows. In this case, the control unit 31 generates analysis-unsuitable information for the 80th to 90th frames and adds the generated analysis-unsuitable information to each of the 80th to 90th frames. After generating the analysis-unsuitable information, the control unit 31 proceeds to step S104.

[0050] The control unit 31 determines whether the comparison of all set comparison frame waveforms Fa, etc. has been completed (step S104). If the control unit 31 determines that the comparison of all set comparison frame waveforms Fa, etc. has not been completed, it returns to step S102. The control unit 31 moves the comparison target with the reference frame waveform FS to an adjacent comparison frame waveform, etc., and repeatedly executes the comparison process of the reference frame waveform FS as described above. On the other hand, if the control unit 31 determines that the comparison with all set comparison frame waveforms Fa, etc. has been completed, it proceeds to step S17 shown in Figure 4.

[0051] If the process branches to the second process in step S13 of Figure 4, the control unit 31 executes the second process on the acquired motion image (step S15). In this case, the control unit 31 proceeds to the subroutine shown in Figure 8. Figure 8 is a flowchart showing an example of the operation of the control unit 31 during the second process according to this embodiment.

[0052] The control unit 31 sets multiple frame waveforms in the dose waveform within each respiratory cycle (step S200). Figure 9 is a diagram showing a dose waveform in which a first frame waveform F1, a second frame waveform F2, a third frame waveform F3, and a fourth frame waveform F4 are set within each respiratory cycle according to this embodiment. In the first respiratory cycle C1, the control unit 31 sets the first frame waveform F1 during the maximum inspiratory period, the second frame waveform F2 during the expiratory period, the third frame waveform F3 during the maximum expiratory period, and the fourth frame waveform F4 during the inspiratory period. In the second respiratory cycle C2 and beyond, the control unit 31 sets the first frame waveform F1, the second frame waveform F2, the third frame waveform F3, and the fourth frame waveform F4 in the same manner as in the first respiratory cycle C1.

[0053] Here, the first frame waveform F1 is composed of multiple frame images during the maximum inspiratory period. The second frame waveform F2 is composed of multiple frame images at approximately the midpoint between the maximum inspiratory position and the maximum expiratory position. The third frame waveform F3 is composed of multiple frame images during the maximum expiratory period. The fourth frame waveform F4 is composed of multiple frame images at approximately the midpoint between the maximum expiratory position and the maximum inspiratory position. Note that the number of frame waveforms to be set is not limited to Figure 9. Also, the setting position of the frame waveform is not limited to Figure 9 and can be set to any position (period) of the dose waveform.

[0054] The control unit 31 compares frame waveforms within the same period set for each respiratory cycle. Based on the comparison results, the control unit 31 determines whether or not there is an abnormality in any of the multiple frame waveforms within each respiratory cycle (step S201). Specifically, as shown in Figure 9, the control unit 31 compares the first frame waveform F1, the second frame waveform F2, the third frame waveform F3, and the fourth frame waveform F4, which are set for each n respiratory cycles. n is a positive integer. The control unit 31 may also determine the similarity between each frame waveform based on the number of peaks in each frame waveform, the width of the waveform signal values, etc.

[0055] If the first frame waveform F1 of the first respiratory cycle C1 does not contain any frame waveforms with low similarity to the corresponding frame waveforms of other respiratory cycles, the control unit 31 determines that the first respiratory cycle C1 does not contain periodic noise. The control unit 31 performs the same processing on other respiratory cycles as it did on the first respiratory cycle. If no periodic noise is found in any respiratory cycle, the control unit 31 determines that there are no abnormalities in any respiratory cycle. In this case, the control unit 31 proceeds to step S17 in Figure 4.

[0056] On the other hand, if the first frame waveform F1 of the first respiratory cycle C1 contains a frame waveform that has low similarity to the corresponding frame waveform of another respiratory cycle, the control unit 31 determines that the first respiratory cycle C1 contains periodic noise. The control unit 31 performs the same processing on other respiratory cycles as it did on the first respiratory cycle. If periodic noise is found in at least one respiratory cycle, the control unit 31 determines that there is an abnormality in one of the respiratory cycles. In this case, the control unit 31 extracts the respiratory cycle containing the periodic noise and proceeds to step S202.

[0057] The control unit 31 generates analysis-unsuitable information for the frame waveforms of the extracted respiratory cycles that have abnormalities, indicating that they are unsuitable for dynamic analysis processing (step S202). For example, the control unit 31 may extract respiratory cycles with less periodic noise by adding analysis-unsuitable information to all frame waveforms of the identified respiratory cycles. Once the control unit 31 has generated the analysis-unsuitable information, it proceeds to step S17 in Figure 4.

[0058] If the process branches to the third process in step S13 of Figure 4, the control unit 31 performs the third process on the acquired motion images (step S16). Specifically, the control unit 31 determines a frame image from a normal location that is assumed not to contain body motion, among the signal value waveforms when the region of interest R of each frame is considered as the overall image, as the reference frame image. The control unit 31 calculates the similarity between each frame of a specific number of frames to be used for motion analysis and the reference frame image. The similarity can be determined using signal values, etc., as described above. Based on the similarity comparison results, the control unit 31 determines that frame images with low similarity that exceed a threshold are abnormal frame images containing noise due to body motion, and extracts the frame images with low similarity. The control unit 31 may discard the extracted frame images, or it may add information that makes the frame images unanalyzable to the extracted frame images as described above.

[0059] The control unit 31 uses the generated dose waveform to perform dynamic analysis processing according to the purpose (step S17). If the first and second processes have been performed, the control unit 31 performs dynamic analysis processing on frame images in which no unanalyzable information has been added to the dynamic image. In other words, the control unit 31 performs dynamic analysis processing on frame images in which noise caused by patient movement, etc., is not included.

[0060] The control unit 31 displays the generated dose waveform and dynamic analysis results on the screen of the display unit 34 (step S18). For example, when the control unit 31 has performed the first and second processes, it displays the results of the dynamic analysis process performed on frame images that do not have analysis-unavailable information attached on the screen of the display unit 34. At this time, the control unit 31 may also display a pop-up message on the screen of the display unit 34 indicating that frame images with analysis-unavailable information attached are not used for dynamic analysis processing.

[0061] According to this embodiment, by performing the first process, the dynamic analysis device 3 compares the reference frame waveform and the comparison frame waveform in the dose waveform and extracts the comparison frame waveform that does not match the reference frame waveform. This makes it possible to extract frame waveforms containing noise due to random body movement fluctuations of the patient from the respiratory cycle of the dose waveform. Furthermore, the dynamic analysis device 3 uses frame images of the maximum inspiratory period or maximum expiratory period, which are the timings when respiratory fluctuations stabilize, as the reference frame waveform. Therefore, since only frame images of the portion with little respiratory fluctuation can be extracted from the dose waveform, a highly accurate dynamic image that does not include random body movement fluctuations can be obtained. As a result, a predetermined dynamic analysis can be performed using an appropriate dynamic image, and accurate analysis results can be obtained.

[0062] According to this embodiment, by performing the second process, the dynamic analysis device 3 can determine that periodic noise, such as involuntary movements of neurological symptoms or arrhythmias, is present in a respiratory cycle if it detects that the respiratory cycle contains frame waveforms with low similarity among the multiple frame waveforms set for each respiratory cycle. Furthermore, the dynamic analysis device 3 adds information indicating that analysis is not possible to the frame waveforms of respiratory cycles containing periodic noise, thereby enabling the acquisition of highly accurate dynamic images. As a result, a predetermined dynamic analysis can be performed using appropriate dynamic images, thus obtaining accurate analysis results.

[0063] Although preferred embodiments of this disclosure have been described in detail above with reference to the attached drawings, the technical scope of this disclosure is not limited to these examples. Furthermore, various modifications and improvements naturally fall within the technical scope of this disclosure, within the scope of the technical ideas described in the claims, as would be expected by those skilled in the art.

[0064] For example, in the above embodiment, the motion analysis device 3 performed the process of extracting noise such as random fluctuations in the patient's body movement included in the motion image, but it is not limited to this. For example, the console 2 may function as a motion image processing device and perform the process of extracting noise included in the motion image. An information processing device such as a client terminal may function as a motion image processing device and perform the process of extracting noise included in the motion image.

[0065] Furthermore, in the above embodiment, the operation unit 33 and display unit 34 of the motion analysis device 3 were used to extract noise contained in the motion image, but the invention is not limited to this. For example, the operation unit and display unit of an information processing device on another client terminal connected to the network N may be used. In this case, the motion analysis device 3 may not have an operation unit 33 and a display unit 34. [Explanation of symbols]

[0066] 3. Dynamic Analysis Device (Dynamic Image Processing Device) 31 Control Unit (First Generation Unit, Extraction Unit, Second Generation Unit, Setting Unit) FS Reference Frame Waveform (First Waveform Information) Fa, Fb, Fc, Fd, Fe, Ff, Fg Comparison frame waveform (second waveform information) R Area of ​​interest (specified area)

Claims

1. A first generation unit generates waveform information including blood flow fluctuations and respiratory fluctuations in a predetermined region of each frame image constituting a dynamic image obtained by dynamic imaging using radiation, An extraction unit extracts waveform information from the waveform information generated by the first generation unit that includes dose fluctuations different from the blood flow fluctuations and respiratory fluctuations, A motion image processing device equipped with the following features.

2. The system includes a second generation unit that generates information indicating that the waveform information extracted by the extraction unit is a motion image unsuitable for motion analysis. The motion image processing apparatus according to claim 1.

3. The extraction unit extracts the second waveform information if the first waveform information and the second waveform information do not match, based on a comparison between the first waveform information, which serves as a reference in the waveform information, and the second waveform information which is different from the first waveform information. The motion image processing apparatus according to claim 1.

4. The first waveform information includes multiple frame images during the maximum respiratory cycle or multiple frame images during the maximum inspiratory period due to the respiratory variation. The dynamic image processing apparatus according to claim 3.

5. The system includes a setting unit that sets the first waveform information based on the type of dynamic analysis. The dynamic image processing apparatus according to claim 3.

6. The extraction unit extracts the second waveform information when the second waveform information includes fluctuations in the patient's body movement. The dynamic image processing apparatus according to claim 3.

7. The first generation unit generates the waveform information based on the signal value of each pixel in the predetermined region of each frame image of the motion image. The motion image processing apparatus according to claim 1.

8. A generation step that generates waveform information including blood flow fluctuations and respiratory fluctuations in a predetermined region of each frame image constituting a dynamic image obtained by dynamic imaging using radiation, Extraction step of extracting waveform information from the generated waveform information that includes dose fluctuations different from the blood flow fluctuations and respiratory fluctuations, A motion image processing method having the following characteristics.

9. Computers, A generation unit that generates waveform information including blood flow fluctuations and respiratory fluctuations in a predetermined region of each frame image constituting a dynamic image obtained by dynamic imaging using radiation. An extraction unit extracts waveform information from the waveform information generated by the generation unit that includes dose fluctuations different from the blood flow fluctuations and respiratory fluctuations. A program designed to function as such.

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