JP2012187383A - Ultrasonic diagnostic apparatus, image processor, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate diagnosing the condition of propagation of cardiac excitation.SOLUTION: This ultrasonic diagnostic apparatus includes a motion information generation section 17a, an extraction section 17b, an image generation section 14, and a control section 18. The motion information generation section 17a scans the heart of a subject three-dimensionally with ultrasound, to produce motion information on the heart wall motion based on groups of volume data each produced in chronological order. The extraction section 17b extracts a unique region, related to motion information in a certain range, from each volume data. The image generation section 14 generates a superimposed image of a unique region regarding target volume data, which is superimposed on the unique region with its previously-produced target volume data being maintained. The control section 18 displays the superimposed image generated by the image generation section 14.

Description

  Embodiments described herein relate generally to an ultrasonic diagnostic apparatus, an image processing apparatus, and a program.

  Objective and quantitative evaluation of the function of biological tissue is important in diagnosing a disease in the biological tissue. For example, in the diagnosis of cardiac disease, cardiac wall motion is quantitatively evaluated by echocardiography. A quantitative evaluation method has been tried.

  As an example of a quantitative evaluation method using echocardiography, there is a method using speckle tracking that tracks a point set in a myocardium on an ultrasonic image based on a speckle pattern unique to the ultrasonic image. For example, the volumetric data collected by scanning the patient's heart in three dimensions with ultrasound in time series is analyzed by speckle tracking to quantitatively evaluate the heart wall motion of the left ventricle in three dimensions. can do.

  Here, the heart is a tissue of an electromechanical connection system in which the myocardium moves by mechanical activation by electrical stimulation. In recent years, it has been considered that there is a relationship between propagation of electrical stimulation and propagation of mechanical excitement. For example, for the left ventricle, by receiving electrical stimulation in the QRS interval of the electrocardiogram, the left ventricular myocardium having a three-dimensional expansion starts from the apex and synchronizes in a synchronized manner. Cause wall motion. The spatial propagation of wall motion for this purpose (corresponding to the timing of local contraction) can be understood as a state of propagation of mechanical excitement. Therefore, it is considered that a part having a large wall motion information (for example, an index value such as a myocardial strain) that is information related to the heart wall motion corresponds to a “mechanical excitable part”. Therefore, for example, a display method for labeling a region having an index value equal to or greater than a threshold among the index values normalized by the spatial peak value of the wall motion information of each volume data in a plurality of cardiac phases as a singular region Are known. Such a display method provides a doctor with an aspect of excitement propagation by updating a specific part with time.

  However, the above display method does not always display the state of excitation propagation in the heart in an easily understandable manner.

JP 2009-39429 A

  The problem to be solved by the present invention is to provide an ultrasonic diagnostic apparatus, an image processing apparatus, and a program capable of easily discriminating the state of excitation propagation in the heart.

  The ultrasonic diagnostic apparatus according to the embodiment includes a motion information generation unit, an extraction unit, an image generation unit, and a control unit. The motion information generation unit generates motion information related to the motion of the heart wall from each volume data group along a time series generated by three-dimensionally scanning the heart of the subject with ultrasound. The extraction unit extracts, from each volume data, a specific region in which the exercise information generated by the exercise information generation unit falls within a predetermined range. The image generation unit holds the singular region extracted by the extraction unit from the volume data to be processed, and the singular region extracted by the extraction unit from volume data generated before the volume data to be processed. A superimposed image is generated in a state of being overlapped. The control unit controls to display the superimposed image generated by the image generation unit.

FIG. 1 is a diagram for explaining the configuration of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 2 is a diagram for explaining an example of exercise information generated by the exercise information generation unit. FIG. 3 is a diagram for explaining a conventional time phase update type display method. FIG. 4 is a diagram for explaining the image generation unit according to the first embodiment. FIG. 5 is a diagram (1) for explaining a second modified example according to the first embodiment. FIG. 6 is a diagram (2) for explaining the second modified example according to the first embodiment. FIG. 7 is a diagram for explaining a third modification example according to the first embodiment. FIG. 8 is a diagram for explaining a fourth modification example according to the first embodiment. FIG. 9A is a diagram (1) for explaining a fifth modified example according to the first embodiment. FIG. 9-2 is a diagram (2) for explaining the fifth modification example according to the first embodiment. FIG. 10 is a flowchart for explaining processing of the ultrasonic diagnostic apparatus according to the first embodiment. FIG. 11 is a diagram for explaining the second embodiment. FIG. 12 is a diagram (1) for explaining the third embodiment. FIG. 13 is a diagram (2) for explaining the third embodiment.

  Hereinafter, embodiments of an ultrasonic diagnostic apparatus will be described in detail with reference to the accompanying drawings.

(First embodiment)
First, the configuration of the ultrasonic diagnostic apparatus according to the first embodiment will be described. FIG. 1 is a diagram for explaining the configuration of the ultrasonic diagnostic apparatus according to the first embodiment. As shown in FIG. 1, the ultrasonic diagnostic apparatus according to the present embodiment includes an ultrasonic probe 1, a monitor 2, an input device 3, an electrocardiograph 4, and a device main body 10.

  The ultrasonic probe 1 is an external ultrasonic probe that is detachably connected to the apparatus main body 10. The ultrasonic probe 1 includes a plurality of piezoelectric vibrators, and the plurality of piezoelectric vibrators generate ultrasonic waves based on a drive signal supplied from a transmission / reception unit 11 included in the apparatus main body 10 described later. The ultrasonic probe 1 receives a reflected wave from the subject P and converts it into an electrical signal. The ultrasonic probe 1 includes a matching layer provided on the piezoelectric vibrator, a backing material that prevents propagation of ultrasonic waves from the piezoelectric vibrator to the rear, and the like.

  When ultrasonic waves are transmitted from the ultrasonic probe 1 to the subject P, the transmitted ultrasonic waves are reflected one after another at the discontinuous surface of the acoustic impedance in the body tissue of the subject P, and the ultrasonic probe is used as a reflected wave signal. 1 is received by a plurality of piezoelectric vibrators. The amplitude of the received reflected wave signal depends on the difference in acoustic impedance at the discontinuous surface where the ultrasonic wave is reflected. Note that the reflected wave signal when the transmitted ultrasonic pulse is reflected on the moving blood flow or the surface of the heart wall depends on the velocity component of the moving body in the ultrasonic transmission direction due to the Doppler effect. And undergoes a frequency shift.

  Here, the ultrasonic probe 1 according to the first embodiment is an ultrasonic probe capable of two-dimensionally scanning the subject P with the ultrasonic wave by sector scanning and three-dimensionally scanning the subject P. Specifically, the ultrasonic probe 1 according to the first embodiment is an external type that three-dimensionally scans the subject P by swinging a plurality of ultrasonic transducers at a predetermined angle (swing angle). This is a mechanical scan probe.

  In the first embodiment, the ultrasonic probe 1 is a two-dimensional array ultrasonic capable of ultrasonically scanning the subject P in three dimensions by arranging a plurality of ultrasonic transducers in a matrix. Even in the case of an acoustic probe, it is applicable. The two-dimensional array ultrasonic probe is capable of electronically scanning the subject P in three dimensions by electronically focusing and transmitting ultrasonic waves.

  The input device 3 includes a mouse, a keyboard, a button, a panel switch, a touch command screen, a foot switch, a trackball, and the like, accepts various setting requests from an operator of the ultrasonic diagnostic apparatus, and accepts them to the apparatus body 10. Transfer various setting requests.

  For example, the input device 3 according to the first embodiment receives from the operator designation of the type of information on the heart wall motion generated from the volume data and designation of the output form of the generated information. Various specification contents received by the input device 3 according to the first embodiment will be described in detail later.

  The monitor 2 displays a GUI (Graphical User Interface) for an operator of the ultrasonic diagnostic apparatus to input various setting requests using the input device 3, and displays various images generated in the apparatus main body 10. Or

  The electrocardiograph 4 is connected to the apparatus main body 10 and acquires an electrocardiogram (ECG) of the subject P on which ultrasonic scanning is performed. The electrocardiograph 4 transmits the acquired electrocardiogram to the apparatus main body 10.

  The apparatus main body 10 is an apparatus that generates an ultrasonic image based on the reflected wave received by the ultrasonic probe 1. Specifically, the apparatus main body 10 according to the first embodiment is an apparatus that can generate a three-dimensional ultrasonic image (volume data) based on the three-dimensional reflected wave data received by the ultrasonic probe 1. As shown in FIG. 1, the apparatus body 10 includes a transmission / reception unit 11, a B-mode processing unit 12, a Doppler processing unit 13, an image generation unit 14, an image memory 15, an internal storage unit 16, and volume data processing. A unit 17 and a control unit 18.

  The transmission / reception unit 11 includes a trigger generation circuit, a transmission delay circuit, a pulser circuit, and the like, and supplies a drive signal to the ultrasonic probe 1. The pulsar circuit repeatedly generates rate pulses for forming transmission ultrasonic waves at a predetermined rate frequency. Each transmission delay circuit generates a transmission delay time for each piezoelectric vibrator necessary for determining transmission directivity by focusing ultrasonic waves generated from the ultrasonic probe 1 into a beam shape. Give to rate pulse. The trigger generation circuit applies a drive signal (drive pulse) to the ultrasonic probe 1 at a timing based on the rate pulse. That is, the transmission delay circuit arbitrarily adjusts the transmission direction from the piezoelectric vibrator surface by changing the transmission delay time given to each rate pulse.

  The transmission / reception unit 11 has a function capable of instantaneously changing a transmission frequency, a transmission drive voltage, and the like in order to execute a predetermined scan sequence based on an instruction from the control unit 18 described later. In particular, the change of the transmission drive voltage is realized by a linear amplifier type transmission circuit capable of instantaneously switching its value or a mechanism for electrically switching a plurality of power supply units.

  The transmission / reception unit 11 includes an amplifier circuit, an A / D converter, a reception delay circuit, an adder, and the like, and performs various processes on the reflected wave signal received by the ultrasonic probe 1 to generate reflected wave data. To do. The amplifier circuit amplifies the reflected wave signal for each channel and performs gain correction processing. The A / D converter A / D converts the reflected wave signal whose gain is corrected. The reception delay circuit gives a reception delay time necessary for determining the reception directivity to the digital data. The adder performs the addition process of the reflected wave signal given the reception delay time by the reception delay circuit to generate the reflected wave data. By the addition processing of the adder, the reflection component from the direction corresponding to the reception directivity of the reflected wave signal is emphasized.

  As described above, the transmission / reception unit 11 controls transmission directivity and reception directivity in ultrasonic transmission / reception. Here, the transmission / reception unit 11 according to the first embodiment transmits an ultrasonic beam in three dimensions from the ultrasonic probe 1 to the subject P, and from the three-dimensional reflected wave signal received by the ultrasonic probe 1. Three-dimensional reflected wave data is generated.

  The B-mode processing unit 12 receives the reflected wave data from the transmission / reception unit 11 and performs logarithmic amplification, envelope detection processing, and the like to generate data (B-mode data) in which the signal intensity is expressed by brightness. .

  The Doppler processing unit 13 performs frequency analysis on velocity information from the reflected wave data received from the transmission / reception unit 11, extracts blood flow, tissue, and contrast agent echo components due to the Doppler effect, and mobile body information such as average velocity, dispersion, and power. Is generated for multiple points (Doppler data).

  Note that the B-mode processing unit 12 and the Doppler processing unit 13 according to the first embodiment can process both two-dimensional reflected wave data and three-dimensional reflected wave data. That is, the B-mode processing unit 12 according to the first embodiment can generate three-dimensional B-mode data from the three-dimensional reflected wave data. The Doppler processing unit 13 according to the first embodiment can generate three-dimensional Doppler data from the three-dimensional reflected wave data.

  The image generation unit 14 generates an ultrasound image from the data generated by the B mode processing unit 12 and the Doppler processing unit 13. That is, the image generation unit 14 generates a B-mode image in which the intensity of the reflected wave is represented by luminance from the B-mode data generated by the B-mode processing unit 12. Specifically, the image generation unit 14 generates a three-dimensional B-mode image from the three-dimensional B-mode data generated by the B-mode processing unit 12.

  In addition, the image generation unit 14 generates a color Doppler image as an average velocity image, a dispersed image, a power image, or a combination image representing moving body information from the Doppler data generated by the Doppler processing unit 13. Specifically, the image generation unit 14 generates a three-dimensional color Doppler image from the three-dimensional Doppler data generated by the Doppler processing unit 13.

  Hereinafter, the three-dimensional B-mode image generated by the image generation unit 14 is referred to as “volume data”.

  Here, the image generation unit 14 generally converts (scan converts) a scanning line signal sequence of ultrasonic scanning into a scanning line signal sequence of a video format typified by a television or the like, and serves as a display image. Generate an ultrasound image. Specifically, the image generation unit 14 generates an ultrasonic image as a display image by performing coordinate conversion in accordance with the ultrasonic scanning mode of the ultrasonic probe 1. In addition to the scan conversion, the image generation unit 14 performs various image processing, such as image processing (smoothing processing) for regenerating an average luminance image using a plurality of image frames after scan conversion, Image processing (edge enhancement processing) using a differential filter is performed in the image.

  The image generation unit 14 can also generate a composite image in which character information, scales, body marks, and the like of various parameters are combined with the ultrasonic image.

  The image generation unit 14 can generate various images for displaying volume data on the monitor 2. Specifically, the image generation unit 14 can generate an MPR (Multi Planar Reconstructions) image and a rendering image (volume rendering image or surface rendering image) from the ultrasound volume data.

  The image memory 15 is a memory that stores the ultrasonic image generated by the image generation unit 14. Here, the image generation unit 14 stores the volume data and the time of the ultrasonic scanning performed for generating the volume data in the image memory 15 in association with the electrocardiogram transmitted from the electrocardiograph 4. . That is, the volume data processing unit 17 to be described later can acquire the cardiac time phase at the time of ultrasonic scanning performed for generating the volume data by referring to the data stored in the image memory 15. The image memory 15 can also store data generated by the B-mode processing unit 12 and the Doppler processing unit 13.

  The internal storage unit 16 stores a control program for performing ultrasonic transmission / reception, image processing and display processing, diagnostic information (for example, patient ID, doctor's findings, etc.), various data such as a diagnostic protocol and various body marks. To do. The internal storage unit 16 is also used for storing images stored in the image memory 15 as necessary. The data stored in the internal storage unit 16 can be transferred to an external peripheral device via an interface (not shown).

  The volume data processing unit 17 is a processing unit that performs various types of image processing on the volume data stored in the image memory 15, and includes an exercise information generation unit 17a and an extraction unit 17b as shown in FIG. Further, the image generation unit 14 described above generates various images using the processing result of the volume data processing unit 17. The processing performed by the volume data processing unit 17 and the image generated by the image generation unit 14 using the processing result of the volume data processing unit 17 will be described in detail later.

  The control unit 18 controls the entire processing of the ultrasonic diagnostic apparatus. Specifically, the control unit 18 is based on various setting requests input from the operator via the input device 3 and various control programs and various data read from the internal storage unit 16. Controls the processing of the processing unit 12, Doppler processing unit 13, image generation unit 14, and volume data processing unit 17. Further, the control unit 18 is based on the ultrasonic image stored in the image memory 15, the GUI for designating various processes performed by the volume data processing unit 17, and the processing result of the volume data processing unit 17. Is controlled to display on the monitor 2 the image generated by.

  The overall configuration of the ultrasonic diagnostic apparatus according to the first embodiment has been described above. With this configuration, the ultrasonic diagnostic apparatus according to the first embodiment generates volume data and performs processing on the generated volume data. Specifically, the ultrasonic diagnostic apparatus according to the first embodiment generates volume data of the heart of the subject P. For example, the ultrasonic diagnostic apparatus according to the first embodiment has a plurality of volume data obtained by photographing the left ventricle (LV) of the heart of the subject P in a time series over a period of one heartbeat or more. (Volume data group) is generated.

  The ultrasonic diagnostic apparatus according to the first embodiment performs processing by the volume data processing unit 17 and the image generation unit 14 on the volume data group of the heart of the subject P, so that the state of excitation propagation in the heart is Generate and display the rendered image.

  First, the motion information generation unit 17a shown in FIG. 1 obtains motion information regarding the motion of the heart wall from each of the volume data groups along the time series generated by three-dimensionally scanning the heart of the subject P with ultrasound. Generate. Specifically, the exercise information generation unit 17a generates exercise information by pattern matching between volume data. More specifically, the motion information generation unit 17a calculates the movement vector of each tracking point by tracking the tracking point set in the myocardial tissue depicted in each volume data based on the speckle pattern. Then, the motion information generation unit 17a generates motion information indicating local myocardial motion using the movement vector of each tracking point. In other words, the exercise information generation unit 17a performs three-dimensional speckle tracking to generate exercise information.

  For example, the motion information generation unit 17a generates a local area change rate of the heart tissue as the motion information.

  For example, the input device 3 receives a setting request from the operator to set the volume data collected at the reference time phase in the volume data group as the volume data of the first frame. As the reference time phase, for example, the cardiac time phase in which the left ventricle is most expanded is selected. The control unit 18 to which the setting request has been transferred selects the volume data generated as the reference time phase volume data at the earliest time from the volume data group based on the information associated with each volume data. To do. Then, the control unit 18 reads the selected volume data from the image memory 15 as the volume data of the first frame. Then, the control unit 18 transfers the read volume data of the first frame to the exercise information generation unit 17a. By setting the first frame, the volume data after the reference time phase becomes “second frame, third frame,..., Nth frame”.

  When determining the local area change rate, the motion information generation unit 17a extracts, for example, the myocardial intimal surface included in the volume data of the first frame. In the present embodiment, the motion information generation unit 17a extracts the left ventricular membrane surface. FIG. 2 is a diagram for explaining an example of exercise information generated by the exercise information generation unit.

  As illustrated in FIG. 2, the motion information generation unit 17 a sets a plurality of tracking points on the left ventricular membrane surface included in the volume data of the first frame. For example, as shown in FIG. 2, the motion information generation unit 17a sets a mesh composed of a plurality of rectangles on the left ventricular membrane surface, and sets the vertices of each rectangle as tracking points. Note that the mesh for setting the tracking point is manually set by an operator referring to a plurality of MPR images obtained by cutting the volume data of the first frame at a plurality of cross sections and a surface rendering image of the left ventricular surface. It may be set.

  Then, the exercise information generation unit 17a tracks to which position each tracking point set in the first frame has moved by speckle tracking in each frame after the first frame. For example, as illustrated in FIG. 2, the motion information generation unit 17a specifies the position of the nth frame corresponding to each tracking point of the first frame. Then, as shown in FIG. 2, the exercise information generation unit 17a calculates the rectangular area (A1) of the first frame and the rectangular area (An) corresponding to the rectangle of the first frame in the nth frame. . That is, the exercise information generation unit 17a calculates A1 and An for each corresponding rectangle. Then, the exercise information generation unit 17a calculates “((An−A1) / A1) × 100” as the area change rate (unit:%) of the nth frame relative to the first frame. That is, the exercise information generation unit 17a calculates the area of each corresponding rectangle between the volume data, and calculates the area change rate between the rectangles. Thereby, the exercise information generation unit 17a calculates a local area change rate of the left ventricular membrane surface. That is, the motion information generation unit 17a first calculates the area of each local region of the intimal surface (the area of each rectangle) at the reference time phase. Then, the motion information generation unit 17a calculates the rectangular area of each cardiac phase by tracking the tracking points in temporally continuous volume data, and calculates the rectangular area of each cardiac phase, A local area change rate is obtained by normalizing with a rectangular area corresponding to the reference time phase. Thereby, the movement information generation unit 17a obtains a local area change rate indicating how each rectangle is deformed in temporally continuous volume data.

  The exercise information generation unit 17a may calculate a time change rate (Area change rate) of a local area change rate (Area change) as the exercise information. That is, the exercise information generation unit 17a may calculate the time change rate of the area change rate by estimating the time differential value of the local area change rate. In addition, “s, i, p, l” shown in FIG. 2 is a 16 fraction recommended by the American Society of Echocardiography, etc. “sept, lower wall (inf), rear wall (post), Corresponds to “side wall (lat)”.

  Returning to FIG. 1, the extraction unit 17 b extracts, from each volume data, a singular region in which the exercise information generated by the exercise information generation unit 17 a falls within a predetermined range. Specifically, the extraction unit 17b extracts a specific region using the predetermined threshold and a range exceeding the predetermined threshold as the predetermined range. For example, the extraction unit 17b searches for a peak value of exercise information in each volume data. In this embodiment, since the area change rate becomes a negative value, the extraction unit 17b searches for the minimum value as the peak value of the area change rate in each volume data. Then, the extraction unit 17b determines, as a predetermined threshold value, a value obtained by multiplying the peak value searched in each volume data by a predetermined setting value (α, where α is a value greater than or equal to 0 and smaller than 1). . And the extraction part 17b extracts a specific area | region by making into the said predetermined range the range from which the exercise | movement information which the exercise | movement information generation part 17a produced | generated is below a predetermined threshold value. That is, the extraction unit 17b determines the threshold value of the nth frame based on the peak value of the motion information of the nth frame and “α”.

  Note that when the cardiac time phase in which the left ventricle contracts most is selected as the reference time phase, the area change rate becomes a positive value. Therefore, the extraction unit 17b uses the peak value of the area change rate in each volume data. Search for the maximum value as Then, the extraction unit 17b determines a value obtained by multiplying the peak value searched in each volume data by “α” as a predetermined threshold value. Then, the extraction unit 17b extracts a singular region with a range that is equal to or greater than a predetermined threshold as the predetermined range.

  By the way, the extraction process of the singular region may be performed using the value of the exercise information as it is, or may be performed after normalizing the exercise information described below. That is, when extracting the singular region from each volume data, the extraction unit 17b performs the extraction process after normalizing the exercise information with the representative value in the cardiac phase in which the volume data to be processed is generated. Specifically, the extraction unit 17b normalizes the exercise information by using a preset value as a representative value.

  For example, the extraction unit 17b sets the representative value in the cardiac phase where the volume data to be processed is generated as the peak value of the local area change rate. Then, the extraction unit 17b normalizes by setting the peak value to “1” and dividing the area change rate other than the peak value by the peak value. Thereby, the extraction unit 17b extracts a region having a value of “α” or more as a singular region in the exercise information (index value of 1 or less) after normalizing each volume data.

  By the way, in the real heart (left ventricle), when “α” is set as a value close to “1”, the region extracted as the singular region based on the normalized motion information is limited to a narrow region, It is difficult to understand the state of excitement propagation. This is because the spatial distribution in the vicinity of the peak of the wall motion index value is pointed (limited to a narrow region).

  Therefore, in order to make it easier to understand the state of excitement propagation, “α” is set to a value close to “0”, the number of areas extracted as specific areas by the normalized motion information is increased, and a wide range of specific areas is obtained. It is necessary to. However, if the singular area is wide, the singular areas of the volume data in each cardiac phase overlap.

  Conventionally, when displaying a singular region, a “time phase update type display method” has been performed. That is, in the time phase update type display method, for example, a superimposed image in which a specific region of the first volume data is superimposed on the surface rendering image of the left ventricular surface included in the first volume data is displayed, and the second volume is displayed. A superimposed image in which a specific region of the second volume data is superimposed on the surface rendering image of the left ventricular membrane surface included in the data is displayed. However, when the singular regions of each cardiac time phase overlap in a wide range, the conventional time phase update type display method makes it difficult to understand the state of excitation propagation.

  FIG. 3 is a diagram for explaining a conventional time phase update type display method. FIG. 3 is an example in which the time phase update type display method is applied to the result of extracting the singular region by “α = 0.2” using the area change rate after normalization. Further, “s, i, p, l” shown in FIG. 3 corresponds to 16 fractions recommended by the American Echocardiographic Society and the like, as in FIG.

  In FIG. 3, the superimposed images of the first frame to the fourth frame are displayed by the time phase update type display method. In FIG. 3, the singular region is displayed in a color tone associated with the cardiac phase of the volume data from which the singular region is extracted. That is, in the example shown in FIG. 3, the singular region is color-coded according to the cardiac time phase of the singular region. By referring to the superimposed images of the first frame to the fourth frame shown in FIG. 3, the operator (for example, a doctor) can identify a specific region of each cardiac phase. However, it is difficult for the operator to grasp the state of excitement propagation in the time phase update type display method because the specific regions of each cardiac time phase overlap in a wide range.

  Therefore, in the first embodiment, processing of the image generation unit 14 described below is performed in order to easily determine the state of excitation propagation in the heart.

  That is, the image generation unit 14 illustrated in FIG. 1 extracts the singular region extracted by the extraction unit 17b from the volume data to be processed from the volume data generated before the volume data to be processed. A superimposed image is generated in a state where the singular region is retained. Further, the image generation unit 14 shown in FIG. 1 generates a superimposed image after changing the color tone assigned to each singular region according to the cardiac phase in which the volume data from which each singular region is extracted is generated. . That is, the image generation unit 14 generates a time phase holding type superimposed image. Then, the control unit 18 illustrated in FIG. 1 performs control so that the superimposed image generated by the image generation unit 14 is displayed on the monitor 2.

  FIG. 4 is a diagram for explaining the image generation unit according to the first embodiment. Note that FIG. 4 relates to the embodiment of the first embodiment with respect to the result of extracting the singular region by “α = 0.2” using the normalized area change rate, as in FIG. It is the superimposed image which the image generation part 14 produced | generated. Also, “s, i, p, l” shown in FIG. 4 corresponds to 16 fractions recommended by the American Echocardiographic Society, etc., as in FIG.

  For example, as shown in FIG. 4, the image generation unit 14 converts the singular region of the first frame colored with a color corresponding to the cardiac time phase of the first frame into a surface rendering image of the left ventricular surface of the first frame. A superimposed image is generated. Then, when processing the volume data of the second frame, the image generation unit 14 converts the singular region of the second frame that does not overlap with the singular region of the first frame, as shown in FIG. And a superimposed image superimposed on the surface rendering image of the left ventricular membrane surface of the second frame is generated.

  Further, when processing the volume data of the third frame, the image generation unit 14 converts the singular region of the third frame that does not overlap with the singular region of the first frame and the second frame, as shown in FIG. A superimposed image is generated by superimposing the surface rendering image of the left ventricular membrane surface of the third frame with a color tone corresponding to the cardiac phase. In addition, when processing the volume data of the fourth frame, the image generation unit 14 converts the singular region of the fourth frame that does not overlap with the singular region of the first frame to the third frame, as shown in FIG. A superimposed image is generated by superimposing the surface rendering image of the left ventricular membrane surface of the fourth frame with a color tone corresponding to the cardiac phase.

  The time phase holding type superimposed image generated by the image generation unit 14 in this way is displayed in parallel or in a moving image on the monitor 2 under the control of the control unit 18.

  That is, in the first embodiment, a part that once exceeds a threshold value in time is considered to be already excited, and a superimposed image that “holds” a time phase that is first excited in that part is displayed. In the first embodiment, among regions that have not yet been labeled (color coded) from all regions, sites that have exceeded a relative threshold value for the first time in a certain cardiac phase are added sequentially with time and labeled (colored). Is encoded). That is, the display method according to the first embodiment is a “time phase maintaining display method”.

  By referring to such a superimposed image, the operator can clearly recognize the site (see the area of the arrow shown in FIG. 4) added sequentially as the cardiac phase elapses. That is, in comparison with FIG. 3 (conventional method), the state of excitement propagation is depicted in FIG. 4 in an easy-to-understand manner. The example shown in FIGS. 3 and 4 shows the response at the contraction start phase in the subject P who has dilated cardiomyopathy with the left leg block.

  By the way, 1st Embodiment may be a case where it implements by the modification shown below. Hereinafter, Modification 1 to Modification 5 according to the first embodiment will be described in order.

  First, a first modification will be described. The first modification relates to the processing of the extraction unit 17b. In the above example, the case where the representative value used for normalization by the extraction unit 17b is a preset value, and this value is the peak value of the motion information of each cardiac phase. That is, in the above example, the representative value is a value that varies according to the volume data group to be processed. However, the preset value may be a fixed value associated with the cardiac time phase.

  For example, when using the area change rate as the exercise information, the operator stores the average area change rate value in each cardiac phase in the healthy case as a table in the internal storage unit 16. In this table, for example, the value of the average area change rate is associated with the elapsed time from the reference time phase. As an example, such a table is “70 msec: −5%, 120 msec: −10%, 140 msec: −15%, 180 msec: −20%, 200 msec: −25%,... . The extraction unit 17b refers to such a table and performs the normalization process with “−5%” as a representative value when processing volume data of “70 msec”. In addition, when the volume data to be processed is a cardiac time phase not set in the table, the extraction unit 17b determines a representative value by interpolating a predetermined value at the nearest time value. For example, when processing volume data of “130 msec”, referring to “120 msec: −10%, 140 msec: −15%”, the average value of “−10%” and “−15%” is “− Normalization processing is performed with “12.5%” as a representative value.

  In addition, when using a fixed value as a representative value, the operator can set a temporally constant value (for example, −20%). Thus, when using a fixed value as a representative value, prepare an individual fixed value according to the type of exercise information, and switch according to the selection of the type of exercise information used to obtain excitement propagation information. It is preferable to set them. The exercise information other than the area change rate and the time change rate of the area change rate will be described later.

  Or the extraction part 17b which concerns on a 1st modification may normalize exercise | movement information by using the spatial extreme value estimated from the exercise | movement information in each cardiac time phase as a representative value. That is, the extraction unit 17b may estimate the peak value from the statistical analysis result of the exercise information, instead of searching for the peak value of the exercise information. When spike noise is mixed into the value of motion information due to the influence of artifacts, it is useful to estimate the peak value by statistical estimation.

  For example, the extraction unit 17b calculates an average value (μ) and standard deviation (sd) of exercise information generated from volume data to be processed. Then, when the value of the exercise information is negative, the extraction unit 17b estimates “μ−k × sd” as the peak value. Alternatively, the extraction unit 17b estimates “μ + k × sd” as the peak value when the value of the exercise information is positive. “K” is preferably a value of “2 to 3”. Thus, estimating the peak value from the statistical analysis result of the exercise information is useful for eliminating the influence of noise.

  Furthermore, the extraction unit 17b according to the first modification standardizes the motion information in a certain local region over each heart time phase instead of performing the process of normalizing the motion information of each point in a certain heart time phase. The process of converting may be performed for each local region. In this case, the extraction unit 17b normalizes the motion information in the local region by using the extreme value (peak value) in the time series section of the motion information in the predetermined local region as a representative value in the local region. Specifically, when the extraction unit 17b normalizes the exercise information, the temporal change of the exercise information in a certain local region is monitored. Then, the extraction unit 17b replaces the spatial peak value with a temporal peak value that the motion information in the local region has within a predetermined section of one cardiac cycle (or systole or diastole). The motion information is normalized by using it as a representative value in the local region. As a local region for this purpose, a representative value may be given at each point (unit of defined minimum space division), or as an average peak value in a minute region in order to add stability. A value may be given.

  By doing in this way, even when the average value in the healthy example of the target exercise information is physiologically distributed between the parts, the normalization of the exercise information is easily performed as intended.

  Here, when monitoring temporal changes in exercise information and obtaining temporal peak values, tracking the movement of the target local region and calculating the peak value while updating the position where the exercise information is monitored Is preferably performed. Since the motion information is obtained by speckle tracking processing by the motion information generation unit 17a, motion information defined while tracking the position by motion within a predetermined section (the motion in the embodiments described so far) As for the information, the same position as obtained by tracking the position in this way may be used. For example, the motion information generation unit 17a tracks the movement of the local region based on data obtained by ultrasonic scanning. Then, when obtaining the extreme value (peak value) in the time series section of the motion information in the local region, the extraction unit 17b obtains the peak value based on the motion information obtained at the tracked local region position. . The motion tracking of the local area may be performed not by the motion information generating unit 17a but by a processing unit separately installed as a tracking unit. For the search of the peak value whose position is tracked, for example, when the Polar-map format shown in FIG. 5 described later is used, this format is given in the coordinate system of the heart. It will be understood that this is easily realized by comparing the values of the motion information in the time direction above.

  The display of the singular region relating to the present embodiment described above is characterized in that an output whose position is tracked in accordance with the local motion of the heart is performed. Therefore, in the search for the peak value of the present modification, it is expected that the accuracy of the local analysis is further increased by tracking the position corresponding to the local motion of the heart.

  In addition, when normalizing exercise information using temporal peak values, it is preferable to set a predetermined lower threshold level in order to detect only effective singular regions after normalization. This lower threshold is effective in preventing erroneous detection of noise and tissue that hardly deforms (such as scar that is a scar due to myocardial infarction).

  As this lower limit threshold, it is preferable to use a value that is about several percent of the global temporal peak value. The global temporal peak value is obtained, for example, by averaging the peak values at each point over the entire region. Or you may set the value previously defined for every exercise | movement information as a lower limit threshold value.

  Subsequently, a second modification will be described. The second modification relates to the processing of the image generation unit 14. In the example shown in FIG. 4, the singular region is superimposed on the surface rendering image by the “time phase maintaining display method”. 5 and 6 are diagrams for explaining a second modification example according to the first embodiment.

  On the other hand, in the second modified example, the image generation unit 14 generates a superimposed image in which the singular region is superimposed on the Polar-map image by the “time phase maintaining display method”. In the example shown in FIG. 5, the 16-fraction Polar-map image recommended by the American Academy of Echocardiography, etc. shows that the singular region until the late expansion (late-diastole) of the subject P who is a healthy subject is “hour”. It is superimposed by the “phase-retaining display method”. Further, in the example shown in FIG. 6, the unique region until the late expansion of the subject P in the left leg block case is superimposed on the 16-fraction Polar-map image by the “time phase holding display method”. Yes. 5 and FIG. 6, “ant-sept” is the front wall septum, “ant” is the front wall, “lat” is the side wall, and “post” is the rear wall. Yes, “inf” is the lower wall and “sept” is the septum.

  Further, in the second modification, the image generation unit 14 includes a time-keeping type superimposed image, an electrocardiogram waveform, a graph of a time change curve of average motion information (average area change rate) every 16 fractions, May be synthesized. In FIG.5 and FIG.6, the time change curve of the average area change rate of each 16 fraction is shown as the continuous line. However, in practice, the image generation unit 14 determines a time change curve of the average motion information of each of the 16 fractions so that the time change curve of each average motion information corresponds to which fraction. It is colored with the color tone assigned to each fraction.

  In FIGS. 5 and 6, the time change curve of the rate of change of the myocardial volume is shown by dotted lines a and c, respectively, along with the time change curve of the average area change rate. In FIGS. 5 and 6, the time change curves of the volume of the heart lumen are shown by dotted lines b and d, respectively. That is, the motion information generation unit 17a sets the tracking point on the outer membrane surface of the myocardium of the left ventricle together with the inner membrane surface of the myocardium of the left ventricle. Can be calculated. Then, the motion information generation unit 17a calculates the volume of the myocardium of each time phase by subtracting the volume of the heart lumen from the volume inside the outer membrane of the myocardium, and calculates the rate of change of the volume of the myocardium. The image generation unit 14 can generate the time change curve graphs shown in FIGS. 5 and 6 by acquiring these pieces of information from the exercise information generation unit 17a. Here, the volume information of the heart lumen has clinically important significance as information such as ejection fraction and left ventricular size. On the other hand, the myocardial weight that can be estimated from the myocardial volume (or the myocardial weight may be normalized by the body surface area) is also used as an index for determining the severity of cardiomyopathy or hypertrophy, for example. Therefore, the significance of being able to observe and evaluate these volume information at the same time as the wall motion index value for each fraction reflecting local wall motion abnormalities is an application to the determination of the effect of cardiac resynchronization therapy described later. It can be said that it is very large.

  By referring to the superimposed image shown in FIG. 5, the operator can grasp at a glance how the uniform excitement propagates in the circumferential direction from the apex to the annulus in a healthy case. On the other hand, by referring to the superimposed image shown in FIG. 6, the operator can grasp at a glance the appearance of abnormal excitement propagation in which the circumferential uniformity is interrupted in the left leg block case. That is, by referring to the superimposed image shown in FIG. 6, in the case of the left leg block, the operator passes the excitement path from the apex to the anterior wall and wraps around the side wall, and the excitement propagation from the apex to the posterior wall. It is possible to grasp at a glance how the septal region is excited after being delayed overall. In addition, by referring to the superimposed image shown in FIG. 6, the operator can see the abnormal early-excitation (septal-flash) aspect, which is a common finding in the case of the left leg block from the septum to the anterior wall septum. Can be understood at a glance.

  At present, the observation of propagation of electrical stimulation of the heart is performed by an electrophysiological mapping device by catheter insertion, which is an invasive and highly invasive diagnostic method. On the other hand, the motion information of the left ventricle depicted in the superimposed images shown in FIG. 5 and FIG. 6 shows the appearance of mechanical excitation propagation, but corresponds to the propagation of electrical stimulation observed as an electrocardiographic waveform. It is thought that there is. Therefore, by using the “time phase holding display method”, diagnostic information similar to that obtained with the electrophysiological mapping device used in the diagnosis of stimulation conduction system abnormalities is non-invasive and simple. It is suggested that it may be obtained.

  Subsequently, a third modification will be described. The third modified example also relates to the processing of the image generation unit 14. In the third modified example, the image generation unit 14 uses an MPR image as an image in which the singular region is superimposed with a time phase holding type. FIG. 7 is a diagram for explaining a third modification example according to the first embodiment.

  For example, the image generation unit 14 generates a plurality of MPR images having a short-axis cross section or a long-axis cross section from the volume data. In the example illustrated in FIG. 7, the image generation unit 14 generates a composite image in which an image in which a specific region is superimposed on the left ventricular heart wall of the apex four-chamber image in the region A is arranged in a time-keeping manner. ing. In the example shown in FIG. 7, the image generation unit 14 generates a composite image in which an image in which a specific region is superimposed on the left ventricular heart wall of the apex two-chamber image in the region B is arranged in a time phase holding type. Is generated.

  In the example illustrated in FIG. 7, the image generation unit 14 arranges an image in which a singular region is superimposed on the left ventricular heart wall of the short-axis cross-sectional image near the apex in the region C3 in a time-keeping manner. A composite image is generated. In the example shown in FIG. 7, the image generation unit 14 arranges an image in which the singular region is superimposed on the left ventricular heart wall of the short-axis cross-sectional image close to the apex in the region C5 in a time-keeping type. A composite image is generated. In the example shown in FIG. 7, the image generation unit 14 has a temporal phase holding type singular region on the left ventricular heart wall of the short-axis cross-sectional image located in the middle between the apex and the base in the region C7. A composite image in which the superimposed images are arranged is generated. In the example shown in FIG. 7, the image generation unit 14 arranges an image in which a singular region is superimposed on the left ventricular heart wall of a short-axis cross-sectional image close to the heart base in a time-keeping type in the region C7. A composite image is generated.

  In the example shown in FIG. 7, the values of various exercise information are displayed as a table together with the color bar and the electrocardiogram waveform. The EDV shown in FIG. 7 is the volume of the heart lumen in the end diastole (ED) phase. In the example illustrated in FIG. 7, the EDV is “156.01 mL” and the end diastole (reference time phase) time is “0 msec”. Moreover, ESV shown in FIG. 7 is the volume of the heart lumen in the end systole (ES) phase. In the example shown in FIG. 7, the ESV is “109.20 mL” and the end systolic time is “422 msec”.

  Moreover, EF shown in FIG. 7 is the ejection ratio defined from EDV and ESV. In the example illustrated in FIG. 7, the EF is “30.01%”. “1.50 × MV” shown in FIG. 7 is obtained by multiplying the myocardial volume (MV) by an average myocardial density value “1.05 g / mL”. It is. In the example illustrated in FIG. 7, “1.50 × MV” is “140.66 g”. In the example shown in FIG. 7, “est.LV MASS” indicating that “140.66 g” is estimated from the myocardial volume of the left ventricle is shown.

  Subsequently, a fourth modification will be described. The fourth modification relates to an output form of information related to the singular region. In the fourth modification, the control unit 18 performs control so as to output time information related to the cardiac phase extracted as the singular region. For example, in the fourth modified example, the control of the control unit 18 causes the image generation unit 14 to display character information regarding the cardiac phase from which volume data from which each singular region is extracted is generated for each singular region. Then, a superimposed image is generated. FIG. 8 is a diagram for explaining a fourth modification example according to the first embodiment.

  In FIGS. 4 to 7, the information on the cardiac phase from which the singular region is extracted is color-coded. On the other hand, in the fourth modification, the information on the cardiac phase from which the singular region is extracted is further superimposed on the singular region as a time value (unit: msec). The example shown in FIG. 8 shows a superimposed image in which a singular region is superimposed on a 16-fraction Polar-map image in a time-phase-holding type, and further, character information (time value) on the cardiac phase is superimposed. ing. In the fourth modified example, the control unit 18 may perform control so as to output time information related to the cardiac phase extracted as the singular region in a text format. For example, the time information related to the cardiac phase extracted as the singular region may be output to the image memory 15 as a text file or printed. Further, the time information related to the cardiac phase extracted as the singular region is converted from text format information into a table or list, and then displayed on the monitor 2, output to the image memory 15, or printed out. It may be a case.

  Subsequently, a fifth modification will be described. The fifth modification relates to a display form of a superimposed image in which a singular region is superimposed in a time phase holding type. The time keeping type display method is also effective in diagnosing the therapeutic effect. In recent years, attention has been focused on Cardiac Resynchronization Therapy (CRT) in which biventricular pacing is performed on patients with severe heart failure. CRT is a treatment that can improve dyssynchrony of heart wall motion, often associated with patients with severe heart failure. Therefore, the doctor can diagnose the effect of the CRT by displaying the time-phase-contained superimposed images in parallel before and after the CRT.

  FIGS. 9A and 9B are diagrams for explaining the fifth modification example according to the first embodiment. 9A and 9B, as described with reference to FIGS. 5 and 6, superimposition in which the singular region is superimposed on the Polar-map image by the “time phase holding display method”. An image and a change curve of motion information of each fraction are displayed. Further, it is assumed that the monitor 2 displays the images shown in FIGS. 9-1 and 9-2 in parallel. Here, the superimposed image shown in FIG. 9A is a superimposed image generated from a volume data group generated before CRT (Pre-CRT). 9B is a superimposed image generated from a volume data group generated after CRT (Post-CRT).

  By referring to the superimposed image in FIG. 9A, the operator can observe that “spetal-flash” has occurred. Furthermore, by referring to the superimposed image in FIG. 9A, the operator can observe that the contraction delay occurs mainly on the front wall septum and the front wall side. On the other hand, by referring to the superimposed image in FIG. 9B, the operator can observe that “spetal-flash” has disappeared. Furthermore, by referring to the superimposed image of FIG. 9-2, the operator can observe how the delay of contraction, which is mainly seen on the front wall septum and the front wall side, is improved. That is, the doctor can confirm the therapeutic effect of CRT or the like by displaying the time phase maintaining superimposed images in parallel before and after the treatment.

  Next, processing of the ultrasonic diagnostic apparatus according to the first embodiment will be described with reference to FIG. FIG. 10 is a flowchart for explaining processing of the ultrasonic diagnostic apparatus according to the first embodiment. In the following, processing after the volume data group is stored in the image memory 15 will be described.

  As shown in FIG. 10, the ultrasonic diagnostic apparatus according to the first embodiment determines whether an image processing request for a volume data group has been received from the operator via the input device 3 (step S101). Here, when the image processing request is not accepted (No at Step S101), the ultrasonic diagnostic apparatus is in a standby state.

  On the other hand, when an image processing request is received (Yes at Step S101), the exercise information generation unit 17a generates exercise information of each volume data (Step S102), and the extraction unit 17b extracts a specific region of each volume data. (Step S103).

  Then, the image generation unit 14 generates a superimposed image in which the singular region is superimposed in a time phase holding type for each cardiac phase (step S104), and the control unit 18 monitors the superimposed image for each cardiac phase. (Step S105), and the process is terminated. Note that the superimposed images for each cardiac phase may be displayed in parallel or displayed as a moving image.

  As described above, in the first embodiment, the motion information generation unit 17a calculates the heart data from each of the volume data groups along the time series generated by three-dimensionally scanning the heart of the subject P with ultrasound. Generate motion information about wall motion. Specifically, the exercise information generation unit 17a generates exercise information by pattern matching between volume data.

  The extraction unit 17b extracts, from each volume data, a singular region in which the exercise information generated by the exercise information generation unit 17a falls within a predetermined range. In the first embodiment, the extraction unit 17b extracts a specific region with a predetermined threshold and a range exceeding the predetermined threshold as a predetermined range.

  The image generation unit 14 retains the singular region extracted by the extraction unit 17b from the volume data to be processed, and the singular region extracted by the extraction unit 17b from the volume data generated before the volume data to be processed. A superimposed image superimposed in a state is generated. Here, the image generation unit 14 generates a superimposed image after changing the color tone assigned to each singular region in accordance with the cardiac phase in which the volume data from which each singular region is extracted is generated. Then, the control unit 18 controls to display the superimposed image generated by the image generation unit 14.

  That is, in the first embodiment, by performing the time phase holding type display method, the presence or absence of abnormal excitement propagation or the site where the abnormal excitement propagation occurs is displayed as a conventional time phase update type display method. In comparison, it can be expressed easily. That is, the operator can grasp and analyze the aspect of the three-dimensional propagation of the motion information analyzed three-dimensionally. For example, in the first embodiment, as described above, in normal cases, uniform excitement propagates in the circumferential direction from the apex to the annulus, whereas abnormal conduction due to arrhythmia or the like is present. Then, it is possible to display an image that can grasp at a glance the aspect of excitement propagation in which the uniformity in the circumferential direction is interrupted. Therefore, in the first embodiment, it is possible to easily determine the state of excitation propagation in the heart.

  In the first embodiment, the exercise information generation unit 17a generates at least one of a local area change rate of the heart tissue or a time change rate of the local area change rate as the exercise information. The area change rate is movement information having information on both expansion and contraction in the circumferential direction and expansion and contraction in the long axis direction. Accordingly, the use of the area change rate or the time change rate of the area change rate as exercise information is a useful index for diagnosing the state of excitation propagation in the heart.

  In the first embodiment, the singular region may be extracted using the normalized motion information. That is, when extracting the singular region from each volume data, the extraction unit 17b performs the extraction process after normalizing the exercise information with the representative value in the cardiac phase in which the volume data to be processed is generated. Specifically, the extraction unit 17b normalizes the exercise information by using a preset value as a representative value. Or the extraction part 17b normalizes exercise | movement information by using the spatial extreme value estimated from the exercise | movement information in each cardiac time phase as a representative value.

  By performing normalization, it is possible to simplify the singular region extraction process from the volumetric data of each cardiac phase. In addition, by making the representative value a statistically estimated peak value, the motion information of the part where excitation propagation is not actually performed is mixed with spike-like noise due to artifacts etc. Therefore, it is possible to avoid being adopted as a peak value.

  In the first embodiment, the control unit 18 performs control so as to output time information related to the cardiac phase extracted as the singular region. According to the first embodiment, further, the time value (time information regarding the cardiac time phase from which the volume data was obtained) on each local position detected as a specific region from the entire left ventricle is defined. Is possible. Therefore, in the first embodiment, the time information may be output in a text file format or displayed on an image via the image generation unit 14. For example, in the above case, the singular region is color-coded and displayed, and the average value of each time value detected as the singular region in each fraction is superimposed and displayed as character information on each singular region. Thereby, the operator can grasp | ascertain quantitatively by numerical value how much excitement propagation is progressing.

(Second Embodiment)
In the second embodiment, a case where an index value of excitement propagation is calculated using a time phase holding type superimposed image will be described with reference to FIG. FIG. 11 is a diagram for explaining the second embodiment.

  In the temporal phase holding type superimposed image, among the parts that are not yet labeled from the entire region, parts that have exceeded a relative threshold value for the first time in a certain time phase are sequentially added and labeled with time. That is, in comparison with the time phase update type superimposed image, the time phase of excitement propagation is divided into fine regions in the time phase holding type superimposed image. Therefore, when a new specific region appears in the next time phase around a specific site labeled at a certain time phase, it is considered that excitement has propagated in the direction of the new specific region that appeared in the next time phase. Can do. That is, the boundary position of the singular region in a certain time phase is detected, and the normal vector between the adjacent boundary lines is obtained for the portion close to the boundary position of the singular region in the next time phase. Thus, the direction of excitement propagation regarding this part can be estimated.

  Therefore, in the second embodiment, the extraction unit 17b further calculates temporal change information related to the temporal change in the boundary position between singular regions in successive cardiac phases. The extraction unit 17b can acquire position information of a singular region in each volume data. Therefore, as illustrated in FIG. 11A, the extraction unit 17b, when a boundary position L1 of the new singular region in the current phase appears around the boundary position L0 of the singular region of the previous cardiac time phase, A normal line starting from the point P0 on L0 is generated, and a point P1 that is the intersection of the generated normal line and the boundary position L1 is specified. That is, the extraction unit 17b calculates the “normal vector P0P1” having the point P0 as the start point and the point P1 as the end point as the temporal change information regarding the temporal change in the boundary position. The magnitude of the normal vector can be regarded as the magnitude of the excitation propagation velocity vector. The magnitude of the excitation propagation velocity vector is preferably estimated as a value obtained by dividing the magnitude of the normal vector P0P1 by two.

  Then, the control unit 18 according to the second embodiment controls to output temporal change information. For example, the image generation unit 14 according to the second embodiment further generates a superimposed image after superimposing the temporal change information calculated by the extraction unit 17b on the singular region under the control of the control unit 18. For example, as illustrated in FIG. 11B, the image generation unit 14 has an arrow indicating the normal vector calculated by the extraction unit 17 b at the boundary position of the singular region superimposed on the Polar-map image of the second frame. Is superimposed. Here, the length of the arrow is one half the size of the normal vector. Further, as shown in FIG. 11B, the image generation unit 14 performs the same process for the third frame. Then, the control unit 18 causes the monitor 2 to display the superimposed image shown in FIG.

  In the second embodiment, the extraction unit 17b may further calculate excitement propagation speed information based on temporal change information (normal vector, excitement propagation speed vector). That is, the extraction unit 17b can also calculate the value of the excitation propagation velocity value (unit: cm / sec) by dividing the excitation propagation velocity vector by the time interval between frames. Information on the excitation propagation speed calculated by the extraction unit 17 b is output under the control of the control unit 18. Specifically, under the control of the control unit 18, the image generation unit 14 further superimposes the excitation propagation speed information calculated by the extraction unit 17 b on the singular region, and then generates a superimposed image. The superimposed image is displayed. In the second embodiment, only one of the temporal change information and the excitement propagation speed information is output even when both the temporal change information and the excitement propagation speed information are output. It may be the case. Moreover, the output form of temporal change information and excitement propagation speed is not limited to the case where it is displayed as a superimposed image as described above. For example, the time change information (excitation propagation speed vector) and the excitation propagation speed may be displayed as a time change graph (time change curve) or may be output as a numerical text file.

  As described above, in the second embodiment, the extraction unit 17b further calculates temporal change information regarding the temporal change of the boundary position between the singular regions in successive cardiac phases, and the calculated time The information of excitement propagation speed is calculated using the change information. And the control part 18 is controlled to output at least one of the information of time change information or excitement propagation speed. For example, the control unit 18 causes the image generation unit 14 to generate a superimposed image after superimposing the temporal change information calculated by the extraction unit 17b on the singular region. In the second embodiment, specific information related to the excitation propagation speed can be provided. Therefore, in the second embodiment, it is possible to more easily determine the state of excitation propagation in the heart. Further, the temporal change information (excitation propagation velocity vector) and the excitation propagation velocity, which are information on temporal changes in the boundary position of the singular region obtained by the extraction unit 17b, are displayed as a time change curve, It may be output as a numerical text file. Such an output form also makes it possible to more easily determine the state of excitation propagation in the heart.

(Third embodiment)
In the third embodiment, a modified example of the method for extracting the singular region used for the temporal phase maintaining type superimposed image will be described with reference to FIGS. 12 and 13. FIG. 12 and FIG. 13 are diagrams for explaining the third embodiment.

  In the first embodiment, the extraction unit 17b obtains, for example, an index value normalized with the peak value of each cardiac phase, and extracts a region where the index value is equal to or greater than a threshold value (α) as a unique region. In the third embodiment, when the extraction method of the singular region of the first embodiment is the first extraction method, the second extraction method or the third extraction method described below is executed by the extraction unit 17b. Is done.

  First, the second extraction method will be described. When executing the second extraction method, the extraction unit 17b extracts a singular region using a plurality of ranges set from predetermined section values as a predetermined range. That is, in the second extraction method, a part where the exercise information is in a range of a plurality of predetermined values is extracted as a specific area. For example, the extraction unit 17b classifies the index values obtained by normalizing the exercise information with the peak value of each cardiac time phase into four levels. That is, as described in the first embodiment, the exercise information (index value) normalized by the peak value is a value of “1.0” or less.

  Therefore, the extraction unit 17b divides the index value into four levels, for example, by setting a predetermined plurality of stages as “4”. That is, the extraction unit 17b sets the index values to “0.0 to 0.25”, “0.25 to 0.5”, “0.5 to 0.75”, and “0.75 to 1.0”. Divide into 4 sections. Then, the extraction unit 17b sets a plurality of ranges based on a preset value “δ”. That is, the extraction unit 17b has a first range of “(0.25−δ) to (0.25 + δ)” as illustrated in FIG. 12 with respect to “0.25” that is a boundary level between section values. Set. In addition, the extraction unit 17b has a second range of “(0.5−δ) to (0.5 + δ)” as illustrated in FIG. 12 with respect to “0.5” which is the boundary level between the section values. Set. In addition, the extraction unit 17b has a third range of “(0.75−δ) to (0.75 + δ)” as illustrated in FIG. 12 with respect to “0.75” which is the boundary level between the section values. Set. The extraction unit 17b sets a fourth range of “(1.0−δ) to 1.0” as shown in FIG. 12 for “1.0” which is the boundary level.

  And the extraction part 17b extracts the area | region applicable to a 1st range-a 4th range as a singular area | region. In other words, in the second extraction method, a plurality of regions corresponding to contour lines are extracted as singular regions from an index value obtained by standardizing exercise information. The singular region extracted by the second extraction method is displayed on the monitor 2 after being superimposed on the surface rendering image, the Polar-map image, and the MRP image in a time phase maintaining manner, as in the first embodiment. Is done.

  Also in the second extraction method, the extraction unit 17b performs the normalization process using a plurality of fixed values or one fixed value as a representative value, as described as the first modification of the first embodiment. Can be done. Also in the second extraction method, the extraction unit 17b performs the normalization process using the statistically estimated peak value as a representative value, as described as the first modification of the first embodiment. be able to.

  Next, the third extraction method will be described. At the forefront position of excitement propagation, it is considered that a local peak distribution appears as a ridgeline of a mountain or valley in the value of motion information. That is, the state of excitement propagation can be imaged as ripples spreading on the water surface by dropping water drops. Such a local peak distribution can be extracted as a region where the spatial total differential “df” of the motion information “f” is close to zero. Therefore, when executing the third extraction method, the extraction unit 17b extracts a singular region with a range including a value in which the exercise information is spatially extreme as a predetermined range.

  Specifically, the extraction unit 17b sets “ε” to a value close to zero (for example, 0.01), and detects a region where | df | <ε as a singular region as illustrated in FIG. By setting “ε”, the width of the singular region corresponding to the ridgeline of the mountain or valley can be controlled. When a relatively large value is used as “ε”, the width increases and the singular region has a linear distribution. On the other hand, when “ε” is set to be small, the singular region has a point-like distribution for obtaining a maximum (or minimum) value. The singular region extracted by the third extraction method is displayed on the monitor 2 after being superimposed on the surface rendering image, the Polar-map image, and the MRP image in a time phase holding manner, as in the first embodiment. Is done.

  As described above, in the third embodiment, as the second extraction method, the extraction unit 17b extracts a singular region using a plurality of ranges set from predetermined section values as a predetermined range. . By performing the second extraction method, it is possible to grasp the excitement region in the same time phase that is difficult to identify due to insufficient time resolution of the volume data by not labeling using the level gap. Since spatial continuity is expected in the motion information obtained from the living body, if it can be considered that “a portion with a relatively large value is excited faster than a portion with a small value”, the second The above effects can be achieved by the extraction method.

  Or in 3rd Embodiment, the extraction part 17b is a 3rd extraction method, and the extraction part 17b extracts the specific area | region by making into a predetermined | prescribed range the range containing the value from which exercise information becomes a spatial extreme value. To do. By performing the third extraction method, it is possible to easily grasp the forefront position of excitement propagation.

  In the first to third embodiments described above, the case has been described in which left ventricular motion information is generated as motion information. However, the exercise information is not limited to the left ventricle, and may be exercise information of the left atrium, right ventricle, and right atrium. Further, in the first to third embodiments described above, the exercise information generation unit 17a has been described when generating a local area change rate or a time change rate of the local area change rate as exercise information. . However, the exercise information generated by the exercise information generation unit 17a may be as follows. That is, the motion information generation unit 17a may generate, as motion information, a local strain of the heart tissue and a strain rate that is a temporal change rate of the local strain of the heart tissue. Further, the motion information generation unit 17a may generate, as motion information, a local rotation of the heart tissue and a rotation rate that is a time change rate of the local rotation of the heart tissue. Further, the motion information generation unit 17a may generate, as motion information, a local twist of the heart tissue and a twist rate that is a time change rate of the local twist of the heart tissue. Further, the motion information generation unit 17a may generate, as motion information, a local displacement of the heart tissue or a speed that is a time change rate of the local displacement of the heart tissue.

  The exercise information generation unit 17a can generate at least one exercise information selected from the exercise information. In addition, when a plurality of pieces of motion information are generated, the extraction unit 17b extracts a singular region for each piece of exercise information, and the image generation unit 14 generates a time phase holding type superimposed image for each piece of exercise information. Generate. The monitor 2 displays a superimposed image for each piece of exercise information.

  Further, in the first to third embodiments described above, the case where the processing for the volume data group is performed in the ultrasonic diagnostic apparatus has been described. However, the above-described processing for the volume data group may be performed by an image processing apparatus installed independently of the ultrasonic diagnostic apparatus. Specifically, the image processing apparatus having the display control functions of the volume data processing unit 17, the image generation unit 14, and the control unit 18 shown in FIG. 1 is an ultrasonic diagnostic apparatus, a PACS database, or an electronic medical record system. It may be a case where the volume data group received from the database is received and the above-described image processing is performed.

  In the first to third embodiments described above and the image processing apparatus described above, the case where the processing for the volume data group is performed has been described. However, the series of image processing described above is performed by obtaining three-dimensional motion information distribution information by synthesizing a plurality of two-dimensional cross-sectional data at different positions instead of using the volume data. There may be.

  In such a case, the motion information generation unit 17a uses a plurality of cross-sectional data groups along a time series generated by scanning so as to include a plurality of two-dimensional regions among the target regions of the subject's heart. Then, a three-dimensional distribution in the target region of motion information regarding the motion of the heart wall is generated. And the extraction part 17b extracts the specific area | region where the exercise | movement information which the exercise | movement information generation part 17a produced | generated becomes a predetermined range from the exercise | movement information distributed to the object area | region. Then, the image generation unit 14 uses the plurality of pieces of cross-sectional data generated before the plurality of pieces of cross-sectional data to be processed as the specific regions extracted by the extraction unit 17b based on the plurality of pieces of cross-section data to be processed. Based on the above, a superimposed image is generated in a state where the singular region extracted by the extraction unit 17b is retained. And the control part 18 is controlled to display a superimposed image. In addition, when extracting the singular region from the plurality of cross-section data, the extraction unit 17b performs the extraction process after normalizing the motion information with the representative value in the cardiac phase when the plurality of cross-section data to be processed is generated. Do. In addition, the image generation unit 14 generates a superimposed image after changing the color tone assigned to each singular region according to the cardiac phase in which a plurality of cross-sectional data from which each singular region is extracted is generated.

  Specifically, the motion information generation unit 17a performs a one-beat moving image of each of the A4C image (apex portion four-chamber image), A2C image (apex portion two-chamber image), and A3C image (apex portion three-chamber image) Motion information is generated by pattern matching between two-dimensional image data. Then, the motion information generation unit 17a obtains spatiotemporal distribution information of the three-dimensional motion information by performing spatial interpolation processing on the motion information in the circumferential direction of the left ventricle. Thus, it is a preferable example to perform extraction of the singular region, generation of a superposition image of the temporal phase holding type of the singular region, and display of the superimposed image.

  In this case, the “volume data processing unit 17” shown in FIG. 1 is replaced with “a plurality of two-dimensional image data processing units 17 ′”, and the description of “volume data” shown in FIG. It will be easily understood that by replacing with “image data”, an essentially equivalent action can be provided.

  However, in this embodiment, since it is necessary to collect a plurality of image data, three-dimensional information at the same heart rate cannot be obtained. In addition, since the actual data can be obtained only in a limited area of about three sections in terms of space, the gap data is estimated by interpolation, so that the spatial resolution is higher than when volume data is obtained. Decreases. Furthermore, since the movement in the direction perpendicular to the cross section cannot be detected, the obtained movement information indicates that the projection component of the three-dimensional movement inherent to the heart is observed.

  On the other hand, in the case of two-dimensional scanning, the frame rate can be kept higher than in the case of three-dimensional scanning when collecting volume data. Has the advantage of high time resolution.

  An ultrasonic diagnostic apparatus capable of three-dimensional scanning requires a two-dimensional array probe as the ultrasonic probe 1. On the other hand, in the case of this embodiment, since a general one-dimensional array of probes can be applied as the ultrasonic probe 1, the ultrasonic diagnostic apparatus can be configured more simply.

  Alternatively, the series of image processing described above may be performed using only one cross section without using a plurality of images obtained by two-dimensional scanning as in the above-described modification.

  In this case, the motion information generation unit 17a uses the cross-sectional data group along the time series generated by two-dimensionally scanning the subject's heart with ultrasound, and the motion information related to the motion of the heart wall 2 A two-dimensional distribution in the two-dimensional scanning region is generated. And the extraction part 17b extracts the specific area | region where the exercise | movement information which the exercise | movement information generation part 17a produced | generated becomes a predetermined range from cross-sectional data. Then, the image generation unit 14 holds the singular region extracted by the extraction unit 17b from the cross-sectional data to be processed, and the singular region extracted by the extraction unit 17b from the cross-sectional data generated before the cross-sectional data to be processed. A superimposed image is generated in a superimposed state. And the control part 18 is controlled to display a superimposed image. In addition, when extracting the singular region from one cross-section data, the extraction unit 17b performs the extraction process after normalizing the motion information with the representative value in the cardiac phase when one cross-section data to be processed is generated. Do. In addition, the image generation unit 14 generates a superimposed image after changing the color tone assigned to each singular region in accordance with the cardiac phase in which one cross-sectional data from which each singular region is extracted is generated.

  In this case, the “volume data processing unit 17” shown in FIG. 1 is replaced with “2D image data processing unit 17 ″”, and the description of “volume data” shown in FIG. 10 is changed to “2D image data”. Replacing provides essentially the same effect. However, the display form of the output image is not limited to the three-dimensional display described so far, and is limited to a two-dimensional expression obtained by coloring a two-dimensional image. For example, two-dimensional image data in which an image in which a specific region is superimposed on the left ventricular heart wall of the apex four-chamber image as shown in region A of FIG. 7 is displayed as an output image. The

  Therefore, in this embodiment, the grasp of the distribution of the specific region related to the main image processing in the output (corresponding to the information of mechanical excitation propagation) is limited to the two-dimensional specific region in the scanned heart. become. However, since the original two-dimensional image has a high spatio-temporal resolution, information on mechanical excitation propagation in the target two-dimensional region can be grasped with a relatively high spatio-temporal resolution. Have advantages.

  Note that the image processing method described in the present embodiment can be realized by executing an image processing program prepared in advance on a computer such as a personal computer or a workstation. This image processing program can be distributed via a network such as the Internet. The image processing program can also be executed by being recorded on a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, or a DVD, and being read from the recording medium by the computer. .

  As described above, according to the first to third embodiments, it is possible to easily determine the state of excitation propagation in the heart.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Monitor 3 Input apparatus 4 Electrocardiograph 10 Apparatus main body 11 Transmission / reception part 12 B mode processing part 13 Doppler processing part 14 Image generation part 15 Image memory 16 Internal storage part 17 Volume data processing part 17a Motion information generation part 17b Extraction unit 18 Control unit

Claims (23)

A motion information generating unit that generates motion information related to the motion of the heart wall from each of the volume data groups in time series generated by three-dimensionally scanning the heart of the subject with ultrasound;
An extraction unit that extracts a specific region in which the exercise information generated by the exercise information generation unit is in a predetermined range from each volume data;
The singular region extracted by the extraction unit from the volume data to be processed is superimposed with the singular region extracted by the extraction unit from the volume data generated before the volume data to be processed being retained An image generation unit for generating a superimposed image;
A control unit that controls to display the superimposed image generated by the image generation unit;
An ultrasonic diagnostic apparatus comprising: Using the plurality of cross-sectional data groups along the time series generated by scanning so as to include a plurality of two-dimensional regions among the target regions of the subject's heart, the motion information related to the motion of the heart wall A motion information generator that generates a three-dimensional distribution in the target region;
An extraction unit that extracts a specific region in which the exercise information generated by the exercise information generation unit is in a predetermined range from the exercise information distributed in the target region;
The extraction unit extracts the singular region extracted by the extraction unit based on a plurality of cross-section data to be processed based on a plurality of cross-section data generated before the plurality of cross-section data to be processed. An image generation unit that generates a superimposed image in a state where the extracted singular region is retained;
A control unit that controls to display the superimposed image generated by the image generation unit;
An ultrasonic diagnostic apparatus comprising: A two-dimensional distribution in the two-dimensional scanning region of motion information relating to the motion of the heart wall is obtained using a cross-sectional data group along a time series generated by two-dimensionally scanning the heart of the subject with ultrasound. An exercise information generation unit to generate,
An extraction unit that extracts from the cross-sectional data a singular region in which the exercise information generated by the exercise information generation unit falls within a predetermined range;
The singular region extracted by the extraction unit from the cross-sectional data to be processed is superimposed with the singular region extracted by the extraction unit from the cross-sectional data generated before the cross-sectional data to be processed being retained. An image generation unit for generating a superimposed image;
A control unit that controls to display the superimposed image generated by the image generation unit;
An ultrasonic diagnostic apparatus comprising:   The ultrasonic diagnosis according to any one of claims 1 to 3, wherein the extraction unit extracts the specific region using the predetermined threshold and a range exceeding the predetermined threshold as the predetermined range. apparatus.   4. The extraction unit according to claim 1, wherein the extraction unit extracts the singular region using a plurality of ranges set from predetermined section values as the predetermined range. 5. Ultrasonic diagnostic equipment.   The said extraction part extracts the said specific area | region by making into the said predetermined range the range containing the value from which the said exercise | movement information becomes an extreme value spatially. Ultrasound diagnostic equipment.   When the extraction unit extracts the singular region from each volume data or at least one or more cross-section data, the representative value in the cardiac phase in which the volume data or at least one or more cross-section data to be processed is generated The ultrasonic diagnostic apparatus according to claim 4 or 5, wherein the extraction process is performed after the motion information is standardized by the method.   The ultrasonic diagnostic apparatus according to claim 7, wherein the extraction unit normalizes the motion information by using a preset value as the representative value.   The super extractor according to claim 7, wherein the extraction unit normalizes the motion information by using a spatial extreme value estimated from the motion information in each cardiac time phase as the representative value. Ultrasonic diagnostic equipment.   The extraction unit normalizes the motion information in the local region by using an extreme value in a time series section of the motion information in a predetermined local region as the representative value in the local region. The ultrasonic diagnostic apparatus according to claim 7. A tracking unit that tracks the movement of the local region based on the data obtained by the scanning;
Further comprising
The extraction unit obtains the extreme value within the time series section of the motion information in the local region, based on the motion information obtained at the position of the local region tracked by the tracking unit. The ultrasonic diagnostic apparatus according to claim 10, wherein:   The image generation unit changes the color to be assigned to each singular region in accordance with a cardiac time phase in which volume data from which each singular region is extracted or at least one cross-sectional data is generated, and then the superimposed image The ultrasonic diagnostic apparatus according to any one of claims 1 to 11, wherein:   The ultrasonic diagnostic apparatus according to claim 1, wherein the control unit controls to output time information related to a cardiac time phase extracted as the singular region. The extraction unit further calculates temporal change information related to temporal changes in boundary positions between specific regions in successive cardiac time phases, and calculates excitement propagation velocity information using the calculated temporal change information. And
The ultrasonic diagnostic apparatus according to claim 1, wherein the control unit controls to output at least one of the temporal change information or the excitement propagation speed information.   The motion information generation unit generates at least one of a local area change rate of a heart tissue or a time change rate of a local area change rate as the motion information. The ultrasonic diagnostic apparatus according to any one of 14.   The motion information generation unit includes, as the motion information, a local distortion of the heart tissue, a strain rate that is a temporal change rate of the local distortion of the heart tissue, a local rotation of the heart tissue, a local of the heart tissue Rotation rate, which is the rate of time change of general rotation, local twist of heart tissue, Twist rate, which is the time change rate of local twist of the heart tissue, local displacement of heart tissue, or the heart tissue The ultrasonic diagnostic apparatus according to claim 1, wherein at least one of the velocities, which is a time change rate of the local displacement, is generated.   The ultrasonic diagnostic apparatus according to claim 1, wherein the motion information generation unit generates the motion information by a process including pattern matching between time series data. A motion information generating unit that generates motion information related to the motion of the heart wall from each of the volume data groups in time series generated by three-dimensionally scanning the heart of the subject with ultrasound;
An extraction unit that extracts a specific region in which the exercise information generated by the exercise information generation unit is in a predetermined range from each volume data;
The singular region extracted by the extraction unit from the volume data to be processed is superimposed with the singular region extracted by the extraction unit from the volume data generated before the volume data to be processed being retained An image generation unit for generating a superimposed image;
A control unit that controls to display the superimposed image generated by the image generation unit;
An image processing apparatus comprising: Using the plurality of cross-sectional data groups along the time series generated by scanning so as to include a plurality of two-dimensional regions among the target regions of the subject's heart, the motion information related to the motion of the heart wall A motion information generator that generates a three-dimensional distribution in the target region;
An extraction unit that extracts a specific region in which the exercise information generated by the exercise information generation unit is in a predetermined range from the exercise information distributed in the target region;
The extraction unit extracts the singular region extracted by the extraction unit based on a plurality of cross-section data to be processed based on a plurality of cross-section data generated before the plurality of cross-section data to be processed. An image generation unit that generates a superimposed image in a state where the extracted singular region is retained;
A control unit that controls to display the superimposed image generated by the image generation unit;
An image processing apparatus comprising: A two-dimensional distribution in the two-dimensional scanning region of motion information relating to the motion of the heart wall is obtained using a cross-sectional data group along a time series generated by two-dimensionally scanning the heart of the subject with ultrasound. An exercise information generation unit to generate,
An extraction unit that extracts from the cross-sectional data a singular region in which the exercise information generated by the exercise information generation unit falls within a predetermined range;
The singular region extracted by the extraction unit from the cross-sectional data to be processed is superimposed with the singular region extracted by the extraction unit from the cross-sectional data generated before the cross-sectional data to be processed being retained. An image generation unit for generating a superimposed image;
A control unit that controls to display the superimposed image generated by the image generation unit;
An image processing apparatus comprising: A motion information generation procedure for generating motion information related to the motion of the heart wall from each of the volume data groups along the time series generated by three-dimensionally scanning the heart of the subject with ultrasound;
An extraction procedure for extracting from each volume data a singular region in which the exercise information generated by the exercise information generation procedure falls within a predetermined range;
The singular region extracted by the extraction procedure from the volume data to be processed is stored in the state where the singular region extracted by the extraction procedure from the volume data generated before the volume data to be processed is retained. An image generation procedure for generating a superimposed image;
A control procedure for controlling to display the superimposed image generated by the image generation procedure;
An image processing program for causing a computer to execute. Using the plurality of cross-sectional data groups along the time series generated by scanning so as to include a plurality of two-dimensional regions among the target regions of the subject's heart, the motion information related to the motion of the heart wall A motion information generation procedure for generating a three-dimensional distribution in the target region;
An extraction procedure for extracting from the exercise information distributed in the target region a specific region in which the exercise information generated by the exercise information generation procedure is a predetermined range;
The extraction procedure extracts the singular region extracted by the extraction procedure based on a plurality of cross-section data to be processed based on a plurality of cross-section data generated before each of the plurality of cross-section data to be processed. An image generation procedure for generating a superimposed image in a state where the extracted singular region is retained;
A control procedure for controlling to display the superimposed image generated by the image generation procedure;
An image processing program for causing a computer to execute. A two-dimensional distribution in the two-dimensional scanning region of motion information relating to the motion of the heart wall is obtained using a cross-sectional data group along a time series generated by two-dimensionally scanning the heart of the subject with ultrasound. The exercise information generation procedure to be generated;
An extraction procedure for extracting from the cross-sectional data a singular region in which the motion information generated by the motion information generation procedure falls within a predetermined range;
The singular region extracted by the extraction procedure from the cross-sectional data to be processed is superimposed with the singular region extracted by the extraction procedure from the cross-sectional data generated before the cross-sectional data to be processed being retained. An image generation procedure for generating a superimposed image;
A control procedure for controlling to display the superimposed image generated by the image generation procedure;
An image processing program for causing a computer to execute.