JP2020000807A - Dynamic image analysis apparatus and program - Google Patents

Abstract

To provide a dynamic image analysis apparatus and program capable of improving the recognizability of images of a dynamic image analysis result.SOLUTION: According to a diagnostic console 3, a control unit 31 analyzes a predetermined feature amount F from a radiographic dynamic image and displays the predetermined feature amount F on a display unit 34. The control unit 31 also evaluates the reliability of the dynamic image. When the predetermined feature amount F is displayed on the display unit 34, the control unit 31 displays reliability information D2 indicative of the reliability of the dynamic image in association with the predetermined feature amount F.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a dynamic image analysis device and a program.

  2. Description of the Related Art Conventionally, dynamic images obtained by radiographic imaging of dynamics having periodicity of a subject have been used for diagnosis. In the dynamic image, the dynamic of the subject that cannot be captured in the still image can be displayed and analyzed.

  For example, in Patent Document 1, a plurality of volume data (dynamic images) having time information is generated, each image quality information is generated, and motion analysis information of each of the plurality of volume data is generated. A medical image processing apparatus capable of improving the image quality when an image (analysis result image) is generated from a plurality of volume data based on the analysis information and the image quality information is described.

JP 2014-50753 A

  In the medical image processing apparatus described in Patent Literature 1, an image (analysis result image) generated from a plurality of volume data has a parameter that changes according to the reliability of voxels of the volume data. Although correction is performed using a filter, it is not possible to know which area of the image has been corrected and how much by simply looking at the image, and the image has the accuracy intended by the user. Because it is not known, visibility may be rather lowered.

  The present invention has been made in view of the above problems, and has as its object to provide a dynamic image analysis device and a program capable of improving the visibility of an image of a dynamic image analysis result.

In order to solve the above problems, a dynamic image analysis device according to the first aspect of the present invention includes:
A dynamic image analysis device that analyzes a predetermined characteristic amount from a dynamic image obtained by radiography and displays the predetermined characteristic amount on a display unit,
Evaluation means for evaluating the reliability of the dynamic image,
A display control unit for displaying, when the predetermined feature amount is displayed on the display unit, reliability information indicating reliability of the dynamic image evaluated by the evaluation unit in association with the predetermined feature amount; ,
Is provided.

The invention according to claim 2 is the invention according to claim 1,
Detecting means for detecting a body motion of the subject from a series of frame images constituting the dynamic image,
First calculating means for calculating the amount of body movement of the subject detected by the detecting means,
The evaluation unit evaluates the reliability of the dynamic image based on the amount of body movement of the subject calculated by the first calculation unit.

The invention according to claim 3 is the invention according to claim 2,
The evaluation means, when the amount of body motion of the subject calculated by the first calculation means exceeds a threshold related to the amount of the body motion, performs an evaluation that the reliability of the dynamic image is low,
The display control unit displays the reliability information indicating that the reliability of the dynamic image is low on the display unit when the evaluation unit evaluates that the reliability of the dynamic image is low. And displaying, on the display unit, a location where the body motion occurs when the amount of the body motion of the subject exceeds the threshold.

The invention according to claim 4 is the invention according to claim 3,
The display control unit, when the evaluation unit evaluates that the reliability of the dynamic image is low, further displays the amount of body motion exceeding the threshold value on the display unit.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
A second calculating unit that calculates an SN ratio of the pixel signal for each pixel signal of the dynamic image,
The evaluation unit evaluates the reliability of the dynamic image based on the SN ratio calculated by the second calculation unit.

The invention according to claim 6 is the invention according to claim 5,
The evaluation means, when the SN ratio calculated by the second calculation means is less than a threshold value related to the SN ratio, evaluates that the reliability of the dynamic image is low,
The display control unit displays the reliability information indicating that the reliability of the dynamic image is low on the display unit when the evaluation unit evaluates that the reliability of the dynamic image is low. And displaying the pixel position of the pixel signal having the SN ratio less than the threshold value on the display means.

The invention according to claim 7 is the invention according to any one of claims 1 to 6,
A third calculating unit that calculates a correlation coefficient between a signal of a frequency component to be analyzed for the predetermined feature amount extracted from the pixel signal and a predetermined ideal signal for each pixel signal of the dynamic image. ,
The evaluation unit evaluates the reliability of the dynamic image based on the correlation coefficient calculated by the third calculation unit.

The invention according to claim 8 is the invention according to claim 7,
The evaluation means, when the correlation coefficient calculated by the third calculation means is less than a threshold related to the correlation coefficient, performs an evaluation that the reliability of the dynamic image is low,
The display control unit displays the reliability information indicating that the reliability of the dynamic image is low on the display unit when the evaluation unit evaluates that the reliability of the dynamic image is low. And displaying the pixel position of the pixel signal whose correlation coefficient is less than the threshold value on the display means.

The program according to claim 9 is
A computer of a dynamic image analysis device that analyzes a predetermined characteristic amount from a dynamic image obtained by radiography and displays the predetermined characteristic amount on a display unit,
Evaluation means for evaluating the reliability of the dynamic image,
A display control unit that, when the predetermined feature amount is displayed on the display unit, displays reliability information indicating the reliability of the dynamic image evaluated by the evaluation unit in association with the predetermined feature amount;
Function as

  ADVANTAGE OF THE INVENTION According to this invention, the visibility of the image of the analysis result of a dynamic image can be improved.

It is a figure showing the whole dynamic image analysis system composition in an embodiment of the present invention. 2 is a flowchart illustrating a shooting control process executed by a control unit of the shooting console in FIG. 1. 5 is a flowchart illustrating an image analysis process executed by the control unit of the diagnostic console in FIG. 1 in the first embodiment. FIG. 5 is a diagram illustrating an example of an image analysis result displayed on the display unit of the diagnostic console in FIG. 1 in the first embodiment. It is a flowchart which shows the image analysis process performed by the control part of the diagnostic console of FIG. 1 in 2nd Embodiment. FIG. 7 is a diagram for explaining a process of calculating an SN ratio of a pixel signal. FIG. 11 is a diagram illustrating an example of an image analysis result displayed on the display unit of the diagnostic console in FIG. 1 in the second embodiment. 11 is a flowchart illustrating an image analysis process executed by a control unit of the diagnostic console of FIG. 1 in a third embodiment. FIG. 13 is a diagram illustrating an example of an image analysis result displayed on the display unit of the diagnostic console in FIG. 1 according to the third embodiment.

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

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

[Configuration of photographing apparatus 1]
The image capturing apparatus 1 is an image capturing unit that captures dynamics having periodicity (cycles), such as changes in the form of expansion and contraction of the lungs due to respiratory movements, heart beats, and the like. Dynamic imaging refers to irradiating radiation such as X-rays to a subject in a pulsed manner at predetermined time intervals (pulse irradiation) or irradiating continuously at a low dose rate (continuous irradiation) This means that a plurality of images indicating the dynamics of the subject are obtained. A series of images obtained by dynamic shooting is called a dynamic image. Each of the plurality of images constituting the dynamic image is called a frame image. In the following embodiment, a case where dynamic imaging of the chest is performed by pulse irradiation will be described as an example.

The radiation source 11 is arranged at a position facing the radiation detection unit 13 with the subject M interposed therebetween, and irradiates the subject M with radiation (X-rays) under the control of the radiation irradiation control device 12.
The radiation irradiation control device 12 is connected to the imaging console 2 and controls the radiation source 11 based on radiation irradiation conditions input from the imaging console 2 to perform radiation imaging. The radiation irradiation conditions input from the imaging console 2 include, for example, a pulse rate, a pulse width, a pulse interval, the number of imaging frames per image, an X-ray tube current value, an X-ray tube voltage value, an additional filter type, and the like. It is. The pulse rate is the number of times of radiation irradiation per second, and matches the frame rate described later. The pulse width is a radiation irradiation time per one radiation irradiation. The pulse interval is the time from the start of one irradiation to the start of the next irradiation, and coincides with the frame interval described later.

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

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

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

[Configuration of the imaging console 2]
The imaging console 2 outputs radiation irradiation conditions and image reading conditions to the imaging device 1 to control radiation imaging and radiographic image reading operations by the imaging device 1, and also captures a dynamic image acquired by the imaging device 1 This is displayed for confirmation of positioning by a photographer such as the above or confirmation of whether or not the image is suitable for diagnosis.
As shown in FIG. 1, the imaging console 2 includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25, and each unit is connected by a bus 26.

The control unit 21 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory).
). The CPU of the control unit 21 reads the system programs and various processing programs stored in the storage unit 22 according to the operation of the operation unit 23 and expands them in the RAM, and executes a shooting control process described later according to the expanded programs. First, various processes are executed to centrally control the operation of each unit of the imaging console 2 and the radiation irradiation operation and the reading operation of the imaging device 1.

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

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

  The display unit 24 includes a monitor such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube), and displays an input instruction from the operation unit 23, data, and the like according to an instruction of a display signal input from the control unit 21. I do.

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

[Configuration of diagnostic console 3]
The diagnostic console 3 is a dynamic image analysis device that acquires dynamic images from the imaging console 2 and displays the acquired dynamic images and analysis results of the dynamic images to assist a doctor in making a diagnosis.
As shown in FIG. 1, the diagnostic console 3 includes a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, and a communication unit 35, and each unit is connected by a bus 36.

  The control unit 31 includes a CPU, a RAM, and the like. The CPU of the control unit 31 reads the system programs and various processing programs stored in the storage unit 32 according to the operation of the operation unit 33 and expands them in the RAM. Various processes including the process A are executed, and the operation of each unit of the diagnostic console 3 is centrally controlled. The control unit 31 functions as an evaluation unit, a display control unit, a detection unit, and a first calculation unit.

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

  The storage unit 32 stores patient information (eg, patient ID, patient's name, height, weight, age, gender, etc.) and examination information (eg, examination ID, examination date, subject) in the storage unit 32. An electronic medical record device (not shown) stores electronic medical record information corresponding to a dynamic image, such as a region (here, the chest) and the type of dynamic state of the diagnosis target (for example, resting breath, deep breathing, heartbeat, etc.). And may be stored in association with the dynamic image.

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

  The display unit 34 is configured by a monitor such as an LCD and a CRT, and performs various displays in accordance with an instruction of a display signal input from the control unit 31.

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

[Operation of dynamic image analysis system 100]
Next, the operation of the dynamic image analysis system 100 according to the present embodiment will be described.

(Operations of the imaging device 1 and the imaging console 2)
First, the photographing operation by the photographing device 1 and the photographing console 2 will be described.
FIG. 2 shows a photographing control process executed by the control unit 21 of the photographing console 2. The photographing control process is executed in cooperation with the control unit 21 and a program stored in the storage unit 22.

  First, the operation section 23 of the imaging console 2 is operated by the imaging operator to input patient information and examination information of the subject (step S1).

  Next, the radiation irradiation conditions are read from the storage unit 22 and set in the radiation irradiation control device 12, and the image reading conditions are read from the storage unit 22 and set in the read control device 14 (step S2).

  Next, a radiation irradiation instruction by the operation of the operation unit 23 is on standby (step S3). Here, the radiographer performs positioning by arranging the subject M between the radiation source 11 and the radiation detection unit 13. In addition, the subject is instructed on the respiratory state according to the type of dynamics of the diagnosis target. When the preparation for imaging is completed, the operation unit 23 is operated to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input by the operation unit 23 (Step S3; YES), an imaging start instruction is output to the radiation irradiation control device 12 and the reading control device 14, and dynamic imaging is started (Step S4). That is, radiation is irradiated from the radiation source 11 at pulse intervals set in the radiation irradiation control device 12, and a frame image is acquired by the radiation detection unit 13.

  When the imaging of a predetermined number of frames is completed, the control unit 21 outputs an instruction to end the imaging to the radiation irradiation control device 12 and the reading control device 14, and the imaging operation is stopped. The number of frames to be imaged is the number of images that can be imaged in at least one breathing cycle.

  The frame images obtained by the shooting are sequentially input to the shooting console 2 and stored in the storage unit 22 in association with the numbers indicating the shooting order (frame numbers) (step S5), and displayed on the display unit 24. (Step S6). The photographing operator confirms the positioning or the like based on the displayed dynamic image, and determines whether an image suitable for diagnosis has been obtained by photographing (photographing OK) or whether re-photographing is necessary (photographing NG). Then, the user operates the operation unit 23 to input a determination result.

  When a determination result indicating shooting OK is input by a predetermined operation of the operation unit 23 (step S7; YES), an identification ID for identifying a dynamic image is assigned to each of a series of frame images acquired by dynamic imaging. And information such as patient information, examination information, radiation irradiation conditions, image reading conditions, and a number (frame number) indicating the order of imaging (for example, written in the header area of the image data in DICOM format). The data is transmitted to the diagnostic console 3 via the terminal (step S8). Then, this processing ends. On the other hand, when the determination result indicating the photographing NG is input by a predetermined operation of the operation unit 23 (step S7; NO), a series of frame images stored in the storage unit 22 is deleted (step S9), and this processing is performed. finish. In this case, re-imaging is required.

(Operation of diagnostic console 3)
Next, the operation of the diagnostic console 3 will be described.
In the diagnostic console 3, when a series of frame images of the dynamic image are received from the imaging console 2 via the communication unit 35, the control unit 31 and the program stored in the storage unit 32 cooperate with each other. Image analysis processing A shown in FIG.

  In the image analysis processing A, first, a predetermined feature amount is analyzed from the received dynamic image (step S11). Here, examples of the predetermined feature amount include a feature amount related to a ventilation function and a feature amount related to a blood flow function.

Next, each of a series of frame images of the dynamic image to be analyzed is compared (step S12), and the subject's body motion is reduced by attempting to acquire the subject's body motion region using, for example, a known inter-frame difference method. It is determined whether or not it has been detected (step S13).
Here, examples of the body motion include a displacement (lateral displacement, anterior-posterior displacement, etc.) of the entire subject part (chest), and movement of a rib, an outer rib cage, and a breast due to breathing, but are not limited thereto. Absent.

In step S13, when it is determined that the subject's body movement is not detected (step S13; NO), steps S14 to S16 are skipped, and the process proceeds to step S17.
On the other hand, when it is determined in step S13 that the body movement of the subject has been detected (step S13; YES), the amount of the detected body movement is calculated (step S14).

Next, it is determined whether the amount of body movement calculated in step S14 exceeds a threshold value related to the amount of body movement (step S15).
For example, when the body movement of the subject detected in step S13 is a displacement of the entire subject portion (chest), the determination in step S15 is performed using a threshold value (for example, 5 cm) relating to the amount of displacement of the entire subject portion. Processing is performed. If the body movement of the subject detected in step S13 is a movement of a rib, the determination process of step S15 is performed using a threshold (for example, 3 cm) related to the amount of movement of the rib.

In step S15, when it is determined that the amount of body movement calculated in step S14 does not exceed the threshold relating to the amount of body movement (step S15; NO), step S16 is skipped, and the process of step S17 is performed. Move to.
On the other hand, when it is determined in step S15 that the amount of body movement calculated in step S14 exceeds the threshold value related to the amount of body movement (step S15; YES), the reliability of the dynamic image to be analyzed is low. An evaluation of low is made (step S16).

  Next, it is determined whether the comparison of each frame image of the dynamic image has been completed (step S17).

In step S17, when it is determined that the comparison of each frame image of the dynamic image has not been completed (step S17; NO), the process returns to step S12, and the subsequent processes are repeated.
On the other hand, when it is determined in step S17 that the comparison of each frame image of the dynamic image has been completed (step S17; YES), it is determined whether the dynamic image to be analyzed has been evaluated as having low reliability. (Step S18).

  If it is determined in step S18 that the dynamic image to be analyzed has been evaluated as having low reliability (step S18; YES), an image IM1 indicating the feature value F analyzed in step S11 and a step S15 And a body motion information D1 indicating a detection area of the body motion determined to exceed the threshold value and an amount of the body motion, and an image IM2 on which reliability information D2 indicating an evaluation result indicating low reliability is superimposed. , Are displayed side by side on the display unit 34 (step S19), and the image analysis processing A ends. Here, the image IM2 is, for example, one frame image of a dynamic image to be analyzed, and is a frame image when a body motion exceeding the threshold is detected.

For example, when the body movement of the subject detected in step S13 is a movement of a rib and the movement amount of the rib is 5 cm, it is determined that the threshold value (3 cm) has been exceeded as shown in FIG. The image IM2 on which the body motion information D1 indicating the detection area of the ribs and the movement amount of the ribs and the reliability information D2 indicating the evaluation result indicating low reliability are superimposed is the feature amount F analyzed in step S11. Is displayed on the display unit 34 in association with the image IM1 indicating.
In addition, for example, when a lateral displacement exceeding a threshold value is detected in addition to the movement of the ribs, as shown in FIG. 4B, the image IM3 on which the body motion information D3 indicating the occurrence of the lateral displacement is further superimposed. Is displayed on the display unit 34 in association with the image IM1. The body movement information D3 indicating occurrence of the lateral shift includes the shift amount of the lateral shift. When the body movement information D3 is displayed on the display unit 34, the shift amount of the lateral shift is also displayed. You may do so.

  When it is determined in step S18 that the dynamic image to be analyzed has not been evaluated as having low reliability (step S18; NO), only the image IM1 indicating the feature value F analyzed in step S11 is included. The image is displayed on the display unit 34 (step S19), and the image analysis processing A ends.

  As described above, in the first embodiment, the reliability of the dynamic image obtained by the radiography is evaluated, and the image IM1 indicating the predetermined feature value F analyzed from the dynamic image is displayed on the display unit 34. In this case, since the image IM2 on which the reliability information D2 indicating the reliability of the dynamic image is superimposed is displayed in association with the predetermined feature value F, the predetermined feature value displayed on the image IM1 is displayed. It is possible to clarify the reliability of F, and it is possible to give an indication as to whether or not to make a careful judgment on the predetermined feature value F. Therefore, in the first embodiment, it is possible to give an indication as to whether or not to make a careful judgment on the predetermined feature value F, so that the visibility of the predetermined feature value F can be improved.

  In the first embodiment, the body movement of the subject is detected from a series of frame images constituting the dynamic image, the amount of the detected body movement of the subject is calculated, and the calculated amount of the body movement of the subject is calculated. , The reliability of the dynamic image can be evaluated objectively. Therefore, in the first embodiment, since the reliability of the dynamic image can be objectively evaluated, highly accurate evaluation of the reliability of the dynamic image can be performed.

  Further, in the first embodiment, when the calculated amount of body motion of the subject exceeds the threshold regarding the amount of body motion, an evaluation that the reliability of the dynamic image is low is performed, and the dynamic image is evaluated. When the evaluation that the reliability is low is performed, the reliability information D2 indicating that the reliability of the dynamic image is low is displayed on the display unit 34, and the amount of the body movement of the subject exceeds the threshold. Since the body motion information D1 indicating the location (detection area) of the body motion at that time is displayed on the display unit 34, the reliability of the feature amount of any of the predetermined feature amounts F displayed on the image IM1 is determined. Can be easily understood. Therefore, in the first embodiment, it is possible to indicate a place that requires careful judgment on the predetermined feature value F, and it is possible to further improve the visibility of the predetermined feature value F.

  In the first embodiment, when the evaluation that the reliability of the dynamic image is low is performed, the amount of the body motion exceeding the threshold is further displayed on the display unit 34 as the body motion information D1. Therefore, it is possible to easily understand which of the predetermined feature values F displayed in the image IM1 has low reliability of the feature value, and to clearly determine how much influence is exerted by the body motion. can do. Therefore, in the first embodiment, it is possible to give a suggestion on how much more cautious judgment should be made for a portion where the judgment of the predetermined feature value F is necessary. The visibility can be further improved.

<Second embodiment>
Hereinafter, a second embodiment of the present invention will be described.
The configuration in the second embodiment is the same as that described in the first embodiment, except that a program for executing the image analysis processing B is stored in the storage unit 32 of the diagnostic console 3. The description is omitted, and the operation of the second embodiment will be described below.

  FIG. 5 is a flowchart showing an image analysis process B executed by the diagnostic console 3 in the second embodiment. The image analysis processing B is executed in cooperation with the control unit 31 and a program stored in the storage unit 32. The control unit 31 functions as an evaluation unit, a display control unit, and a second calculation unit.

  First, similarly to the image analysis processing A, a predetermined feature F is analyzed from the dynamic image received from the imaging console 2 (step S21).

Next, the SN ratio of the pixel signal of each dynamic image to be analyzed is calculated (step S22).
As a method of calculating the SN ratio of a pixel signal, for example, as shown in FIG. 6, frequency analysis is performed on a pixel signal corresponding to each pixel P of a dynamic image. Then, the S / N ratio of the pixel signal is calculated from the signal intensity of the frequency component to be analyzed and the signal intensity of the noise component obtained by the frequency analysis. The effect of noise is small if the SN ratio is high, and the effect of noise is large if the SN ratio is small.

  Next, it is determined whether or not the SN ratio calculated in step S22 is less than a threshold value related to the SN ratio (step S23).

In step S23, if it is determined that the SN ratio calculated in step S22 is not less than the threshold value related to the SN ratio, that is, it is determined that the influence of noise is small (step S23; NO), step S24 is skipped and step S25 is performed. Move to the processing of.
On the other hand, in step S23, when it is determined that the SN ratio calculated in step S22 is less than the threshold value related to the SN ratio, that is, it is determined that the influence of noise is large (step S23; YES), the dynamic image to be analyzed is not trusted. It is evaluated that the property is low (step S24).

  Next, it is determined whether the SN ratios of all the pixel signals have been calculated (step S25).

If it is determined in step S25 that the SN ratios of all the pixel signals have not been calculated (step S25; NO), the process returns to step S22, and the subsequent processes are repeated.
On the other hand, when it is determined in step S25 that the SN ratios of all the pixel signals have been calculated (step S25; YES), it is determined whether the dynamic image to be analyzed has been evaluated as having low reliability. (Step S26).

  If it is determined in step S26 that the dynamic image to be analyzed has been evaluated as having low reliability (step S26; YES), an image IM1 indicating the feature value F analyzed in step S21, and step S23. And an image IM4 on which the region information R1 of the pixel signal determined to be less than the threshold value, the evaluation result of low reliability, and the reliability information D4 indicating the factor evaluated as low reliability are superimposed. , Are displayed side by side on the display unit 34 (step S9), and the image analysis processing B ends. Here, it is assumed that the image IM4 is one frame image among the dynamic images to be analyzed.

  For example, when the pixels determined that the S / N ratio of the pixel signal is less than the threshold are concentrated near the lower part of the right lung, the S / N ratio of the pixel signal is determined to be less than the threshold as shown in FIG. The image information IM4 on which the region information R1 of the pixel signal and the reliability information D4 indicating the evaluation result indicating low reliability and the factor (noise) evaluated as low reliability are analyzed in step S21. The image 34 is displayed on the display unit 34 in association with the image IM <b> 1 indicating the feature amount F thus set.

  If it is determined in step S26 that the dynamic image to be analyzed has not been evaluated as having low reliability (step S26; NO), only the image IM1 indicating the feature amount analyzed in step S21 is displayed. The image is displayed on the unit 34 (step S28), and the image analysis processing B ends.

  As described above, in the second embodiment, the SN ratio of the pixel signal is calculated for each pixel signal of the dynamic image, and the reliability of the dynamic image is evaluated based on the calculated SN ratio. The reliability can be evaluated objectively. Therefore, in the second embodiment, the reliability of the dynamic image can be objectively evaluated, so that the reliability of the dynamic image can be evaluated with high accuracy.

  Further, in the second embodiment, when the calculated SN ratio is less than the threshold value related to the SN ratio, the evaluation that the reliability of the dynamic image is low is performed, and the evaluation that the reliability of the dynamic image is low is performed. If performed, the reliability information D4 indicating that the reliability of the dynamic image is low is displayed on the display unit 34, and the region information R1 of the pixel signal whose SN ratio is less than the threshold is displayed on the display unit 34. Therefore, it is possible to easily understand which area of the predetermined feature F displayed on the image IM1 has low reliability of the feature. Therefore, in the second embodiment, it is possible to indicate a place that requires careful judgment on the predetermined feature value F, so that the visibility of the predetermined feature value F can be further improved.

<Third embodiment>
Hereinafter, a third embodiment of the present invention will be described.
The configuration in the third embodiment is the same as that described in the first embodiment, except that a program for executing the image analysis processing C is stored in the storage unit 32 of the diagnostic console 3. The description is omitted, and the operation of the third embodiment will be described below.

  FIG. 8 is a flowchart illustrating an image analysis process C executed by the diagnostic console 3 in the third embodiment. The image analysis processing C is executed in cooperation with the control unit 31 and a program stored in the storage unit 32. The control unit 31 functions as an evaluation unit, a display control unit, and a third calculation unit.

  First, similarly to the image analysis processing A, a predetermined feature amount is analyzed from the dynamic image received from the imaging console 2 (step S31).

Next, for each pixel signal of the dynamic image to be analyzed, a correlation coefficient between the signal of the frequency component to be analyzed among the pixel signals and the ideal signal is calculated (step S32).
As a method of calculating the correlation coefficient, for example, as shown in FIG. 6, a frequency analysis is performed on a pixel signal corresponding to each pixel of the dynamic image. Then, a signal of a frequency component to be analyzed obtained by the frequency analysis is extracted, and a correlation coefficient between the extracted signal and an ideal signal set in advance is calculated.

  Next, it is determined whether the correlation coefficient calculated in step S32 is less than a threshold value related to the correlation coefficient (step S33).

If it is determined in step S33 that the correlation coefficient calculated in step S32 is not less than the threshold value related to the correlation coefficient, that is, it is determined that the signal does not deviate from the ideal signal (step S33; NO), step S34 is skipped. Then, the process proceeds to the process of step S35.
On the other hand, if it is determined in step S33 that the correlation coefficient calculated in step S32 is less than the threshold value related to the correlation coefficient, that is, it is determined that the correlation signal deviates from the ideal signal (step S33; YES), the analysis target Is evaluated as having low reliability (step S34).

  Next, it is determined whether correlation coefficients have been calculated for all pixel signals (step S35).

When it is determined in step S35 that the correlation coefficients have not been calculated for all the pixel signals (step S35; NO), the process returns to step S32, and the subsequent processes are repeated.
On the other hand, if it is determined in step S35 that the correlation coefficients have been calculated for all the pixel signals (step S35; YES), it is determined whether the dynamic image to be analyzed has been evaluated as having low reliability. (Step S36).

  When it is determined in step S36 that the dynamic image to be analyzed has been evaluated as having low reliability (step S36; YES), the image IM1 indicating the feature amount analyzed in step S31 and the image IM1 indicating the feature amount analyzed in step S33. Region information R2 of the pixel signal determined to be less than the threshold value, and an image IM5 on which the reliability result is superimposed and the reliability information D5 indicating the factor evaluated as low reliability, Are displayed side by side on the display unit 34 (step S37), and the image analysis processing C ends. Here, it is assumed that the image IM5 is one frame image among the dynamic images to be analyzed.

  For example, when the pixels for which the correlation coefficient is determined to be less than the threshold are concentrated near the lower part of the right lung, as shown in FIG. In step S31, the region information R2 and the image IM5 on which the reliability information D5 indicating the evaluation result of low reliability and the factor (deviation from the ideal signal) evaluated as low reliability are superimposed are analyzed. The image 34 is displayed on the display unit 34 in association with the image IM <b> 1 indicating the feature amount F thus set.

  If it is determined in step S36 that the dynamic image to be analyzed has not been evaluated as having low reliability (step S36; NO), only the image IM1 indicating the feature value analyzed in step S31 is displayed. The image is displayed on the unit 34 (step S38), and the image analysis processing C ends.

  As described above, in the third embodiment, for each pixel signal of the dynamic image, the phase relationship between the signal of the frequency component to be analyzed for the predetermined feature value F extracted from the pixel signal and the predetermined ideal signal Since the number is calculated and the reliability of the dynamic image is evaluated based on the calculated correlation coefficient, the reliability of the dynamic image can be objectively evaluated. Therefore, in the third embodiment, the reliability of the dynamic image can be objectively evaluated, so that the reliability of the dynamic image can be evaluated with high accuracy.

  Further, in the third embodiment, when the calculated correlation coefficient is less than the threshold value related to the correlation coefficient, the evaluation that the reliability of the dynamic image is low is performed, and the reliability of the dynamic image is low. When the evaluation is performed, the reliability information D5 indicating that the reliability of the dynamic image is low is displayed on the display unit 34, and the region information R2 of the pixel signal whose correlation coefficient is less than the threshold is displayed on the display unit. 34, it is possible to easily understand which region of the predetermined feature value F displayed on the image IM1 has low reliability of the feature value. Therefore, in the third embodiment, it is possible to indicate a place that requires careful judgment on the predetermined feature value F, so that the visibility of the predetermined feature value F can be further improved.

  As described above, the first to third embodiments of the present invention have been described, but the description in the embodiments is a preferred example of the present invention, and the present invention is not limited to these.

  For example, in the above embodiment, the case where the subject region is the chest is described as an example. However, the present invention can be applied to a case where an analysis process is performed on a dynamic image obtained by photographing another region.

  In the first embodiment, the case where the control unit 31 of the diagnostic console 3 executes the image analysis processing A has been described as an example. For example, in addition to the image analysis processing A, the control unit 31 At least one of the image analysis processing B described in the embodiment and the image analysis processing C described in the third embodiment may be executed together.

  Further, in the second embodiment, the case where the control unit 31 of the diagnostic console 3 executes the image analysis processing B has been described as an example. However, for example, the control unit 31 may perform the third processing in addition to the image analysis processing B. The image analysis processing C described in the embodiment may be executed together.

  Further, in the first embodiment, when the amount of body movement of the subject calculated by the control unit 31 of the diagnostic console 3 exceeds the threshold regarding the amount of body movement, the reliability of the movement image is low. Although the evaluation is performed, for example, at the stage when the comparison of each frame image is completed, if the determination that the amount of the body movement of the subject has exceeded the threshold regarding the amount of the body movement has never been made, May be evaluated such that the reliability of the dynamic image is high. In such a case, for example, a state in which the reliability information indicating at least the evaluation result indicating high reliability and the image IM1 indicating the predetermined feature value F analyzed by the control unit 31 of the diagnostic console 3 are arranged side by side. Is displayed on the display unit 34.

  In the second embodiment, when the SN ratio calculated by the control unit 31 of the diagnostic console 3 is smaller than a threshold value related to the SN ratio, the evaluation that the reliability of the dynamic image is low is performed. However, for example, when there is a pixel signal for which it is determined that the SN ratio calculated by the control unit 31 of the diagnostic console 3 is equal to or more than the threshold value related to the SN ratio, at least the area information and the reliability of the pixel signal Is displayed on the display unit 34 in a state where the image including the reliability information indicating the evaluation result indicating that the evaluation value is high and the image IM1 indicating the predetermined feature value F analyzed by the diagnostic console 3 are arranged side by side. To do.

  In the third embodiment, when the correlation coefficient calculated by the control unit 31 of the diagnostic console 3 is smaller than a threshold value related to the correlation coefficient, the evaluation that the reliability of the dynamic image is low is performed. However, for example, when there is a pixel signal whose correlation coefficient calculated by the control unit 31 of the diagnostic console 3 is determined to be equal to or more than a threshold value related to the correlation coefficient, at least the area of the pixel signal is determined. An image including information and reliability information indicating an evaluation result indicating high reliability and an image IM1 indicating a feature value F analyzed by the diagnostic console 3 are displayed on the display unit 34 in a state where they are arranged side by side. To be done.

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

  In addition, the detailed configuration and detailed operation of each device constituting the dynamic image analysis system can be appropriately changed without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 100 dynamic image analysis system 1 imaging device 11 radiation source 12 radiation irradiation control device 13 radiation detection unit 14 reading control device 2 imaging console 21 control unit 22 storage unit 23 operation unit 24 display unit 25 communication unit 26 bus 3 diagnostic console 31 Control unit 32 Storage unit 33 Operation unit 34 Display unit 35 Communication unit 36 Bus

Claims (9)

A dynamic image analysis device that analyzes a predetermined characteristic amount from a dynamic image obtained by radiography and displays the predetermined characteristic amount on a display unit,
Evaluation means for evaluating the reliability of the dynamic image,
A display control unit for displaying, when the predetermined feature amount is displayed on the display unit, reliability information indicating reliability of the dynamic image evaluated by the evaluation unit in association with the predetermined feature amount; ,
A dynamic image analysis device, comprising: Detecting means for detecting a body motion of the subject from a series of frame images constituting the dynamic image,
First calculating means for calculating the amount of body movement of the subject detected by the detecting means,
The dynamic image analysis apparatus according to claim 1, wherein the evaluation unit evaluates the reliability of the dynamic image based on the amount of body movement of the subject calculated by the first calculation unit. The evaluation means, when the amount of body motion of the subject calculated by the first calculation means exceeds a threshold related to the amount of the body motion, performs an evaluation that the reliability of the dynamic image is low,
The display control unit displays the reliability information indicating that the reliability of the dynamic image is low on the display unit when the evaluation unit evaluates that the reliability of the dynamic image is low. 3. The dynamic image analysis apparatus according to claim 2, wherein a position where the body motion occurs when the amount of the body motion of the subject exceeds the threshold is displayed on the display unit.   The display control unit, when the evaluation unit evaluates that the reliability of the dynamic image is low, further displays the amount of body motion exceeding the threshold on the display unit. The dynamic image analysis device according to claim 3. A second calculating unit that calculates an SN ratio of the pixel signal for each pixel signal of the dynamic image,
The dynamic image according to any one of claims 1 to 4, wherein the evaluation unit evaluates the reliability of the dynamic image based on the SN ratio calculated by the second calculating unit. Analysis device. The evaluation means, when the SN ratio calculated by the second calculation means is less than a threshold value related to the SN ratio, evaluates that the reliability of the dynamic image is low,
The display control unit displays the reliability information indicating that the reliability of the dynamic image is low on the display unit when the evaluation unit evaluates that the reliability of the dynamic image is low. 6. The dynamic image analyzer according to claim 5, wherein a pixel position of the pixel signal whose SN ratio is less than the threshold is displayed on the display unit. A third calculating unit that calculates a correlation coefficient between a signal of a frequency component to be analyzed for the predetermined feature amount extracted from the pixel signal and a predetermined ideal signal for each pixel signal of the dynamic image. ,
The dynamics according to any one of claims 1 to 6, wherein the evaluation unit evaluates the reliability of the dynamic image based on the correlation coefficient calculated by the third calculating unit. Image analysis device. The evaluation means, when the correlation coefficient calculated by the third calculation means is less than a threshold related to the correlation coefficient, performs an evaluation that the reliability of the dynamic image is low,
The display control unit displays the reliability information indicating that the reliability of the dynamic image is low on the display unit when the evaluation unit evaluates that the reliability of the dynamic image is low. 8. The dynamic image analyzer according to claim 7, wherein a pixel position of the pixel signal whose correlation coefficient is less than the threshold value is displayed on the display unit. A computer of a dynamic image analysis device that analyzes a predetermined characteristic amount from a dynamic image obtained by radiography and displays the predetermined characteristic amount on a display unit,
Evaluation means for evaluating the reliability of the dynamic image,
A display control unit that, when the predetermined feature amount is displayed on the display unit, displays reliability information indicating the reliability of the dynamic image evaluated by the evaluation unit in association with the predetermined feature amount;
Program to function as.

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