Ultrasound diagnostic device and control method for ultrasound diagnostic device

Abstract

This invention provides an ultrasound diagnostic device and a control method for the ultrasound diagnostic device that can support the accurate measurement of cardiac function with a simple device configuration. [Solution] The ultrasound diagnostic device includes an image acquisition unit (31) that acquires multiple frames of ultrasound images of the subject's heart using an ultrasound probe (1), a contour extraction unit (24) that extracts the contours of the cardiac chambers from each of the multiple frames of ultrasound images, a contour correction unit (26) that applies correction processing to the multiple contours of the cardiac chambers extracted from the multiple frames of ultrasound images so that they change smoothly over time, and a display control unit (22) that displays an ultrasound image on a monitor (23) in real time with the contours of the cardiac chambers extracted for each frame superimposed, and also displays an ultrasound image on the monitor (23) with the corrected contours of the cardiac chambers superimposed.

Description

Technical Field

[0001] The present invention relates to an ultrasonic diagnostic apparatus for photographing an ultrasonic image of a subject's heart and a control method for the ultrasonic diagnostic apparatus.

Background Art

[0002] Conventionally, an ultrasonic image representing a tomographic plane of a subject's heart is photographed using a so-called ultrasonic diagnostic apparatus, and using this ultrasonic image, so-called left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume, left ventricular end-systolic volume, E / e' which is an index representing the diastolic function of the left ventricle, MAPSE (Mitral Annular Plane Systolic Excursion), TAPSE (Tricuspid Annular Plane Systolic Excursion), etc. may be measured. Measurement of cardiac function may be performed, for example, at the scene of emergency medical treatment, and in particular, accurate measurement is required in this case.

[0003] Therefore, in order to accurately measure cardiac function, techniques such as those disclosed in Patent Document 1 have been developed. Patent Document 1 discloses an apparatus that selects ultrasonic images corresponding to the end-diastolic and end-systolic phases of the heart by referring to data in which an ultrasonic image, the time of ultrasonic scanning, and the electrocardiogram waveform of the subject are associated, extracts the contour of the cardiac chamber in the selected ultrasonic image, and calculates at least one of the volume and ejection fraction of the cardiac chamber using the information of the extracted contour.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, it is necessary to acquire the subject's electrocardiogram waveform using an electrocardiograph in order to link the ultrasound image and ultrasound scanning time to the subject's electrocardiogram waveform. Thus, in order to accurately measure cardiac function using the technology of Patent Document 1, a complex device configuration was required.

[0006] This invention was made to solve the problems of the conventional methods, and aims to provide an ultrasound diagnostic device and a control method for the ultrasound diagnostic device that can support the accurate measurement of cardiac function with a simple device configuration. [Means for solving the problem]

[0007] The above objective can be achieved with the following configuration. [1] Ultrasound probe and Monitor and, An image acquisition unit that acquires multiple frames of ultrasound images as moving images of the subject's heart by transmitting and receiving ultrasound beams using an ultrasound probe, A contour extraction unit extracts the contours of the cardiac chambers from each of the multiple frames of ultrasound images acquired by the image acquisition unit, A contour correction unit applies correction processing to multiple contours of the cardiac chambers, which are extracted from multiple frames of ultrasound images by a contour extraction unit, so that the multiple contours of the cardiac chambers change smoothly over time. A display control unit displays an ultrasound image on a monitor in real time with the contours of the cardiac chambers extracted by the contour extraction unit superimposed for each frame, and also displays an ultrasound image on the monitor with the contours of the cardiac chambers superimposed after correction processing by the contour correction unit. An ultrasound diagnostic device equipped with the following features. [2] The ultrasound diagnostic apparatus according to [1], further comprising a measurement target image extraction unit that extracts an ultrasound image to be measured from multiple frames of ultrasound images based on the contour of the cardiac chamber extracted by the contour extraction unit. [3] The ultrasound diagnostic apparatus according to [1] or [2], wherein the contour correction unit corrects the contour of the cardiac chamber extracted by the contour extraction unit to ensure consistency with the contour of the cardiac chamber in the anterior and posterior frames. [4] The contour correction unit corrects the contour of the cardiac chambers based on positional information of characteristic structures of the cardiac chambers, as described in [1] or [2]. [5] The contour correction unit is, Based on the contours of the cardiac chambers extracted by the contour extraction unit, heart rate phase information is acquired. An ultrasound diagnostic device according to [1] or [2], which corrects the contours of cardiac chambers so that the positions of the contours of cardiac chambers corresponding to multiple ultrasound images of the same phase in different cardiac cycles are aligned with each other by referring to cardiac phase information. [6] The contour correction unit is: The contour extraction unit calculates the edge line that has the maximum brightness difference in the vicinity of the contour of the cardiac chamber extracted, An ultrasound diagnostic device according to [1] or [2] that corrects the contour of the cardiac chambers so that the contour of the cardiac chambers aligns with the edge lines. [7] The ultrasound diagnostic apparatus according to any one of [1] to [6], wherein the display control unit highlights the portion of the ultrasound image related to the correction performed by the contour correction unit. [8] An ultrasound diagnostic apparatus according to any one of [1] to [6], comprising an image selection unit that selects an ultrasound image from multiple frames of ultrasound images to be used for contour correction of the cardiac chamber contour by a contour correction unit. [9] Equipped with an input device for the user to perform input operations, The ultrasound diagnostic apparatus described in [8], wherein the image selection unit selects an ultrasound image selected by the user via an input device as the image to be corrected.

[10] The contour correction unit further corrects the contour of the cardiac chambers when the user selects a new ultrasound image to be corrected via an input device after the display control unit has displayed an ultrasound image on a monitor in which the corrected contours of the cardiac chambers have been superimposed.

[11] The image selection section is, Based on the contours of the cardiac chambers extracted by the contour extraction unit, heart rate phase information is acquired. The ultrasound diagnostic device described in [8], which selects the ultrasound image to be corrected based on the acquired heart rate phase information.

[12] The ultrasound diagnostic apparatus according to [2], comprising a measurement unit that measures cardiac function using an ultrasound image which is the target of measurement extracted by the measurement target image extraction unit and on which the contours of the cardiac chambers corrected by the contour correction unit are superimposed.

[13] The ultrasound diagnostic apparatus according to

[12] , wherein the display control unit displays the measurement results from the measurement unit together with an ultrasound image on which the contours of the cardiac chambers extracted by the contour extraction unit are superimposed.

[14] The contour correction unit corrects the contour of the cardiac chamber each time the contour extraction unit extracts the contour of the cardiac chamber, as described in [1] to

[13] .

[15] By transmitting and receiving an ultrasound beam using an ultrasound probe, multiple frames of ultrasound images are obtained as moving images of the subject's heart. The contours of the cardiac chambers are extracted from each of the multiple ultrasound images acquired. Multiple contours of the cardiac chambers extracted from multiple frames of ultrasound images are corrected so that they change smoothly over time. A display control unit that displays an ultrasound image on a monitor in real time with the contours of the cardiac chambers extracted for each frame superimposed, and also displays an ultrasound image on the monitor with the corrected contours of the cardiac chambers superimposed. A control method for an ultrasound diagnostic device equipped with the following features. [Effects of the Invention]

[0008] The present invention provides an ultrasonic diagnostic apparatus, comprising: an ultrasonic probe; a monitor; an image acquisition unit that acquires a plurality of frames of ultrasonic images as moving images obtained by transmitting and receiving ultrasonic beams using the ultrasonic probe to image the heart of a subject; a contour extraction unit that extracts the contour of a cardiac chamber from each of the plurality of frames of ultrasonic images acquired by the image acquisition unit; a contour correction unit that performs correction processing on the plurality of contours of the cardiac chamber so that the plurality of contours of the cardiac chamber extracted by the contour extraction unit from the plurality of frames of ultrasonic images change smoothly in time series; and a display control unit that displays, in real time, on the monitor, an ultrasonic image in which the contour of the cardiac chamber extracted by the contour extraction unit for each frame is superimposed, and displays on the monitor an ultrasonic image in which the contour of the cardiac chamber subjected to correction processing by the contour correction unit is superimposed. Therefore, with a simple device configuration, assistance for accurately measuring cardiac function can be provided.

Brief Description of the Drawings

[0009] [Figure 1] It is a block diagram showing the configuration of an ultrasonic diagnostic apparatus according to Embodiment 1 of the present invention. [Figure 2] It is a block diagram showing the internal configuration of a transmission / reception circuit in Embodiment 1 of the present invention. [Figure 3] It is a block diagram showing the internal configuration of an image generation unit in Embodiment 1 of the present invention. [Figure 4] It is a diagram schematically showing an example of an ultrasonic image representing a four-chamber cross-section at the cardiac apex. [Figure 5] It is a diagram showing examples of contours of a cardiac chamber extracted from each of three consecutive frames of ultrasonic images. [Figure 6] It is a diagram showing the contours of a cardiac chamber extracted from each of three consecutive frames of ultrasonic images superimposed on each other. [Figure 7] It is a diagram showing examples of contours of a cardiac chamber extracted from each of three frames of ultrasonic images in the same phase at different cardiac cycle periods. [Figure 8] It is a diagram showing the contours of a cardiac chamber extracted from each of three frames of ultrasonic images in the same phase at different cardiac cycle periods superimposed on each other. [Figure 9] It is a diagram showing an example of the position of characteristic structures in the heart cavity. [Figure 10] It is a diagram showing an example of the contour of the extracted heart cavity and the edge line where the luminance difference of the ultrasonic image is maximized in the vicinity thereof. [Figure 11] It is a diagram showing an example of arranging side by side and displaying an ultrasonic image including the contour of the heart cavity before correction and an ultrasonic image including the contour of the heart cavity after correction. [Figure 12] It is a diagram showing an example of highlighting and displaying correction locations in an ultrasonic image including the contour of the heart cavity after correction. [Figure 13] It is a diagram showing an example of displaying an ultrasonic image in which the contour of the heart cavity is corrected and a correction reference image used for correcting the contour of the heart cavity. [Figure 14] It is a flowchart showing the operation of the ultrasonic diagnostic apparatus according to Embodiment 1 of the present invention. [Figure 15] It is a flowchart showing the operation of the ultrasonic diagnostic apparatus according to Embodiment 2 of the present invention. [Figure 16] It is a block diagram showing the configuration of the ultrasonic diagnostic apparatus according to Embodiment 2 of the present invention.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of this invention will be described based on the accompanying drawings. The description of the constituent elements described below is made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In this specification, "identical" and "the same" are assumed to include an error range generally acceptable in the technical field.

[0011] Embodiment 1 Figure 1 shows the configuration of an ultrasound diagnostic apparatus according to Embodiment 1 of the present invention. The ultrasound diagnostic apparatus comprises an ultrasound probe 1 and a device body 2 that are connected to each other by so-called wired communication or so-called wireless communication.

[0012] The ultrasonic probe 1 comprises a transducer array 11 and a transmitting / receiving circuit 12 connected thereto.

[0013] The main unit 2 of the device includes an image generation unit 21 connected to the transmitting / receiving circuit 12. In the main unit 2, the display control unit 22 and the monitor 23 are sequentially connected to the image generation unit 21. The contour extraction unit 24 and the memory 25 are connected to the contour extraction unit 24. The contour correction unit 26 is connected to the memory 25. The measurement target extraction unit 27 is also connected to the memory 25. The measurement unit 28 is connected to the measurement target extraction unit 27. The measurement unit 28 is connected to the memory 25. The memory 25 is connected to the display control unit 22. Furthermore, the main unit control unit 29 is connected to the transmitting / receiving circuit 12, the image generation unit 21, the display control unit 22, the contour extraction unit 24, the memory 25, the contour correction unit 26, the measurement target extraction unit 27, and the measurement unit 28. The input device 30 is connected to the main unit control unit 29.

[0014] The image acquisition unit 31 is composed of a transmitting / receiving circuit 12 and an image generation unit 21. Furthermore, the processor 32 for the main unit 2 is composed of the image generation unit 21, display control unit 22, contour extraction unit 24, contour correction unit 26, measurement target extraction unit 27, measurement unit 28, and main unit control unit 29.

[0015] The transducer array 11 of the ultrasonic probe 1 has a plurality of ultrasonic transducers arranged in one or two dimensions. Each of these ultrasonic transducers transmits ultrasound according to a drive signal supplied from the transmitting / receiving circuit 12, and also receives ultrasonic echoes from the subject and outputs a signal based on the ultrasonic echoes. Each ultrasonic transducer is constructed by forming electrodes at both ends of a piezoelectric body made of, for example, a piezoelectric ceramic represented by PZT (Lead Zirconate Titanate), a polymer piezoelectric element represented by PVDF (Poly Vinylidene Di Fluoride), or a piezoelectric single crystal represented by PMN-PT (Lead Magnesium Niobate-Lead Titanate).

[0016] The image acquisition unit 31, which consists of a transmitting / receiving circuit 12 and an image generation unit 21, acquires multiple frames of ultrasound images as moving images of the subject's heart by transmitting and receiving an ultrasound beam using an ultrasound probe 1.

[0017] The transmitting / receiving circuit 12 transmits ultrasonic waves from the transducer array 11 and generates a sound line signal based on the received signal acquired by the transducer array 11, under the control of the main unit control 29. As shown in Figure 2, the transmitting / receiving circuit 12 includes a pulser 41 connected to the transducer array 11, and an amplifier 42, an AD (Analog to Digital) converter 43, and a beamformer 44 connected sequentially in series from the transducer array 11.

[0018] The pulser 41 includes, for example, multiple pulse generators, and based on a transmission delay pattern selected according to a control signal from the main unit control 29, it supplies each drive signal to the multiple ultrasonic transducers of the transducer array 11, adjusting the delay amount, so that the ultrasonic waves transmitted from the transducers form an ultrasonic beam. In this way, when a pulsed or continuous wave voltage is applied to the electrodes of the ultrasonic transducers of the transducer array 11, the piezoelectric material expands and contracts, generating pulsed or continuous wave ultrasonic waves from each ultrasonic transducer, and an ultrasonic beam is formed from the combined wave of these ultrasonic waves.

[0019] The transmitted ultrasonic beam is reflected from a target, such as a part of the subject, and propagates toward the transducer array 11 of the ultrasonic probe 1. The ultrasonic echo propagating toward the transducer array 11 is received by each ultrasonic transducer that makes up the transducer array 11. At this time, each ultrasonic transducer that makes up the transducer array 11 expands and contracts upon receiving the propagating ultrasonic echo, generating a received signal which is an electrical signal, and outputs these received signals to the amplification unit 42.

[0020] The amplification unit 42 amplifies the signals input from each ultrasonic transducer constituting the transducer array 11 and transmits the amplified signals to the AD conversion unit 43. The AD conversion unit 43 converts the signals transmitted from the amplification unit 42 into digital received data. The beamformer 44 performs so-called receive focus processing by adding each received data received from the AD conversion unit 43 with a corresponding delay. Through this receive focus processing, each received data converted by the AD conversion unit 43 is phase-corrected and added together, and a sound ray signal with a focused ultrasonic echo is obtained.

[0021] As shown in Figure 3, the image generation unit 21 has a configuration in which a signal processing unit 45, a DSC (Digital Scan Converter) 46, and an image processing unit 47 are connected in series in sequence.

[0022] The signal processing unit 45 receives the sound line signal from the transmitting / receiving circuit 12, and after correcting for attenuation due to distance according to the depth of the ultrasonic reflection position using the sound velocity value set by the main unit control unit 29, it performs envelope detection processing to generate a B-mode image signal, which is tomographic image information of the tissue within the subject.

[0023] The DSC46 converts the B-mode image signal generated by the signal processing unit 45 into an image signal that follows the scanning method of a normal television signal (raster conversion). The image processing unit 47 performs various necessary image processing, such as gradation processing, on the B-mode image signal input from the DSC 46, and then sends the B-mode image signal to the display control unit 22, the contour extraction unit 24, and the memory 25. Hereafter, the B-mode image signal processed by the image processing unit 47 will be referred to as the ultrasound image.

[0024] The ultrasound diagnostic device of Embodiment 1 of the present invention is used to measure cardiac functions such as the so-called left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume, left ventricular end-systolic volume, E / e' (an index representing left ventricular diastolic function), MAPSE (Mitral Annular Plane Systolic Excursion), and TAPSE (Tricuspid Annular Plane Systolic Excursion). For measuring cardiac functions, the image acquisition unit 31 acquires ultrasound images U of multiple frames representing cross-sections of cardiac chambers A, such as the so-called apical four-chamber section 4C of the heart H, as shown in Figure 4. Here, cardiac chamber A refers to any of the left ventricle, left atrium, right ventricle, or right atrium. In addition to the apical four-chamber section (4C), other cross-sections of cardiac chamber A can be imaged, such as the so-called apical two-chamber section, apical three-chamber section, apical five-chamber section, long-axis section, left ventricle long-axis section at the left sternal border, left ventricle short-axis section at the left sternal border, long-axis section at the left sternal border, short-axis section at the left sternal border, four-chamber section at the left sternal border, four-chamber section at the epigastric region, and short-axis section at the epigastric region.

[0025] The display control unit 22, under the control of the main unit control unit 29, performs predetermined processing on the ultrasound image U acquired by the image acquisition unit 31 and displays it on the monitor 23.

[0026] The monitor 23 displays ultrasound images U, etc., under the control of the display control unit 22, and has a display device such as an LCD (Liquid Crystal Display) or an organic EL display (Organic Electroluminescence Display).

[0027] The memory 25 stores ultrasound images U and the like acquired by the image acquisition unit 31 under the control of the main unit control unit 29.

[0028] For memory 25, for example, recording media such as flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), FD (Flexible Disk), MO disk (Magneto-Optical disk), MT (Magnetic Tape), RAM (Random Access Memory), CD (Compact Disc), DVD (Digital Versatile Disc), SD card (Secure Digital card), or USB memory (Universal Serial Bus memory) can be used.

[0029] The main unit control unit 29 controls each part of the main unit 2 and the transmitting / receiving circuit 12 of the ultrasonic probe 1 based on a control program or the like that is stored in advance.

[0030] The input device 30 is for the user to perform input operations and consists of devices such as a keyboard, mouse, trackball, touchpad, and touch sensor placed on top of the monitor 23.

[0031] The contour extraction unit 24 extracts the contour C of cardiac chamber A for each frame by performing image analysis on multiple frames of ultrasound images U acquired by the image acquisition unit 31, for example, as shown in Figure 4. In this figure, the left ventricle is shown as an example of cardiac chamber A.

[0032] The contour extraction unit 24 can extract the contour C of cardiac chamber A from an ultrasound image U by segmentation using a learning model in so-called machine learning, which has learned the relationship between a large number of ultrasound images including cardiac chamber A and the contour C of cardiac chamber A. Alternatively, the contour extraction unit 24 can also extract the contour C of cardiac chamber A from an ultrasound image U using a so-called template matching method, which involves pre-storing multiple template image data representing cardiac chamber A and searching the ultrasound image U using these multiple template image data.

[0033] The process of extracting the contour C of cardiac chamber A by the contour extraction unit 24 is performed each time an ultrasound image U is acquired by the image acquisition unit 31. The contour extraction unit 24 sends the extracted information of the cardiac chamber A contour C to the display control unit 22 and the memory 25.

[0034] Memory 25 stores the ultrasound image U acquired by the image acquisition unit 31 and the information of the contour C of the cardiac chamber A extracted from the ultrasound image U by the contour extraction unit 24, linking them together.

[0035] The display control unit 22 displays the ultrasound image U superimposed with the contour C of heart chamber A on the monitor 23 in real time, as shown in Figure 4, based on the ultrasound image U acquired by the image acquisition unit 31 and the contour C of heart chamber A extracted from the ultrasound image U by the contour extraction unit 24. Here, the ultrasound image U superimposed with the contour C of heart chamber A refers to the ultrasound image U in which the contour C extracted by the contour extraction unit 24 is superimposed in an enhanced state. Furthermore, displaying the ultrasound image U superimposed with the contour C of heart chamber A on the monitor 23 in real time means that each time an ultrasound image U is acquired by the image acquisition unit 31, the ultrasound image U superimposed with the contour C of heart chamber A is sequentially displayed on the monitor 23.

[0036] The contour correction unit 26 applies correction processing to the multiple contours C of the heart chamber A, which are extracted by the contour extraction unit 24 from the multiple frames of ultrasound images U acquired by the image acquisition unit 31, so that they change smoothly over time.

[0037] Generally, it is known that during the diastole of the heart H, the contour C of the cardiac chamber A increases over time, and during the systole of the heart H, the contour C of the cardiac chamber A decreases over time. Therefore, the contour correction unit 26 can, for example, focus on the relative size of the contour C of the cardiac chamber A in relation to preceding and succeeding frames in a time series during the diastole or systole of the heart H, and perform a correction process on multiple contours C of cardiac chamber A extracted by the contour extraction unit 24 to ensure consistency with the contour C of cardiac chamber A in preceding and succeeding frames in the time series.

[0038] Figure 5 schematically shows the contours C1, C2, and C3 of cardiac chamber A in the (N-1), (N), and (N+1) frames of ultrasound images U, which belong to the diastolic phase of the heart H. When the contour correction unit 26 corrects contour C2 in the ultrasound image U of the N frame, it compares the positions of contours C1, C2, and C3, for example as schematically shown in Figure 6. Since the (N-1), (N), and (N+1) frames of ultrasound images U belong to the diastolic phase, contour C2 should be located outside contour C1 and inside contour C3. Therefore, the contour correction unit 26 can deform contour C2 to be located between contours C1 and C3 if, for example, contour C2 is located outside contour C3, as shown in Figure 6. Also, although not shown, the contour correction unit 26 can deform contour C2 to be located between contours C1 and C3 if, for example, contour C2 is located inside contour C1.

[0039] Furthermore, although not shown in the diagram, if the (N-1), (N), and (N+1)th three frames of ultrasound images U belong to the systolic phase of the heart H, then contour C2 should be located inside contour C1 and outside contour C3. In this case, the contour correction unit 26 can deform contour C2 to position it between contour C1 and contour C3, whether contour C2 is located outside contour C1 or inside contour C3.

[0040] Furthermore, the size and shape of the contour C of cardiac chamber A normally change periodically in accordance with the heartbeat. Therefore, even with different heartbeat periods, ultrasound images U of frames in the same phase should ideally depict the contour C of cardiac chamber A having the same size and shape. Thus, the contour correction unit 26 can also correct the contour C of cardiac chamber A, for example, to align the positions of multiple contours C of cardiac chamber A corresponding to multiple ultrasound images U of cardiac chamber A in the same phase at different heartbeat periods.

[0041] Figure 7 schematically shows the contours C4, C5, and C6 of cardiac chamber A in three in-phase ultrasound images U of different heartbeat cycles, corresponding to the volume of cardiac chamber A which changes in accordance with the heartbeat. The contour correction unit 26 first acquires heartbeat phase information representing the phase of each heartbeat cycle based on the contour C of cardiac chamber A extracted by the contour extraction unit 24. At this time, the contour correction unit 26 calculates the volume of cardiac chamber A from the area of ​​cardiac chamber A surrounded by the contour C shown in the ultrasound image U of each frame, and based on the time-series change of the calculated volume of cardiac chamber A, it can acquire as heartbeat phase information the heartbeat cycle number assigned to each heartbeat to distinguish the heartbeat cycles, and the frame number of the ultrasound image U starting from the frame corresponding to the end of systole or end of diastole of the heart H in each heartbeat cycle, i.e., the minimum or maximum value of the volume of cardiac chamber A. Here, the contour correction unit 26 can calculate the volume of the heart chamber A by known methods, such as calculating the total number of pixels surrounded by the extracted contour C.

[0042] Furthermore, the contour correction unit 26, by referring to the acquired heart rate phase information, identifies contours C4, C5, and C6 that appear in multiple ultrasound images U that are in phase with each other in different heart rate cycles, as shown in Figure 7, for example. When correcting contour C2, the contour correction unit 26 compares the positions of contours C4, C5, and C6, as schematically shown in Figure 8, for example. Since contours C4, C5, and C6 belong to different heart rate cycles but are in phase, ideally the positions of contours C4, C5, and C6 should overlap each other. Therefore, if contour C5 is separated from contours C4 and C6, as shown in Figure 8, for example, the contour correction unit 26 can deform contour C5 to overlap contours C4 and C6.

[0043] Furthermore, after acquiring heart rate phase information, the contour correction unit 26 can identify characteristic structures of the cardiac chamber A, such as the apex, mitral valve, or interventricular septum, from the ultrasound image U of each frame, and correct the contour C of cardiac chamber A based on the positional information of the identified structures. Ideally, the position of the interventricular septum or the anterior wall of the left ventricle in the ultrasound image U should be the same if the phases are the same, even if the heart rates are different. Since the interventricular septum or the anterior wall of the left ventricle is usually depicted with high brightness in the ultrasound image U, the contour correction unit 26 identifies the interventricular septum or the anterior wall of the left ventricle that is visible in the ultrasound image U of each frame based on the brightness information of the image. Specifically, the contour correction unit 26 can identify the interventricular septum or the anterior wall of the left ventricle by methods such as using a trained model in machine learning or template matching.

[0044] The contour correction unit 26 moves the entire contour C of the cardiac chamber A in the ultrasound image U of each frame so that the position of the identified interventricular septum or the anterior wall of the left ventricle matches in phase over multiple heartbeat cycles. Furthermore, the contour correction unit 26 identifies structures of interest, such as the apex D and the bases M1 and M2 of the mitral valve, whose positions in the ultrasound image U do not ideally change with each heartbeat, as shown in Figure 9, by using a pre-trained model in machine learning or a template matching method on the ultrasound image U of the frame to be corrected. The contour correction unit 26 compares the positions of the structures of interest with multiple contours C in the same phase over multiple heartbeat cycles and can deform the contour C to match the positions of the structures of interest with multiple contours C in the same phase.

[0045] Furthermore, the contour correction unit 26 can, for example, calculate an edge line E in the vicinity of the contour C of the cardiac chamber A extracted by the contour extraction unit 24 for each frame of the ultrasound image U, as schematically shown in Figure 10, where the brightness difference is maximum, and correct the contour C by deforming the contour C extracted by the contour extraction unit 24 to match the edge line E.

[0046] In this way, the contour correction unit 26 corrects the contour C of cardiac chamber A extracted by the contour extraction unit 24. Therefore, even if any of the contours C of cardiac chamber A extracted by the contour extraction unit 24 deviate from the actual contour C of cardiac chamber A, an accurate contour C can ultimately be obtained. Furthermore, since both the process of extracting contour C by the contour extraction unit 24 and the process of correcting contour C by the contour correction unit 26 are completed solely by image analysis of the ultrasound image U, an accurate contour C can be obtained without requiring a complex device configuration or processing.

[0047] The contour correction unit 26 stores the information of the contour C corrected in this way in the memory 25, linking it to the ultrasound image U in which the contour C is visible.

[0048] The measurement target extraction unit 27 extracts the ultrasound image U to be measured for cardiac function from multiple frames of ultrasound image U, based on the contour C of cardiac chamber A extracted by the contour extraction unit 24. For example, when the ejection fraction of cardiac chamber A is measured as a measure of cardiac function, the ultrasound image U of the frame corresponding to at least one of the end-systolic and end-diastolic phases of the heart H is used as the measurement target. In this case, if, for example, heart rate phase information has been acquired by the contour correction unit 26, the measurement target extraction unit 27 can refer to this heart rate phase information and extract the ultrasound image U of the frame corresponding to at least one of the end-systolic and end-diastolic phases of the heart H as the measurement target. If heart rate phase information has not been acquired by the contour correction unit 26, the measurement target extraction unit 27 can acquire heart rate phase information using the method described as the method by which the contour correction unit 26 acquires heart rate phase information.

[0049] The measurement unit 28 measures cardiac function using an ultrasound image U extracted by the measurement target extraction unit 27, on which the contour C of cardiac chamber A, corrected by the contour correction unit 26, is superimposed. For example, when measuring the ejection fraction of cardiac chamber A as a measure of cardiac function, the measurement unit 28 can calculate the area enclosed by the contour C of cardiac chamber A in the ultrasound image U extracted by the measurement target extraction unit 27, and calculate the ejection fraction of cardiac chamber A based on the calculated area.

[0050] The display control unit 22 can display, for example as shown in Figure 11, an ultrasonic image U1 with contour C extracted by the contour extraction unit 24 superimposed, an ultrasonic image U2 with contour CC corrected by the contour correction unit 26 superimposed, and measured values ​​obtained by the measurement unit 28 on the monitor 23, so that the user can confirm the correction results by the contour correction unit 26 and the measurement results by the measurement unit 28.

[0051] The display control unit 22 can, for example, display on the monitor 23 an ultrasound image U2 and its corresponding ultrasound image U1 specified by the user via the input device 30 from among multiple ultrasound images U. The display control unit 22 can also display on the monitor 23 an ultrasound image U2 extracted by the measurement target extraction unit 27 and the ultrasound image U1 corresponding to that ultrasound image U2. In this case, the display control unit 22 can, for example, display on the monitor 23 a list of ultrasound images U2 with different heartbeat periods and in the same phase as candidates for the ultrasound image U2 to be displayed, and allow the user to select the ultrasound image U2 to be displayed on the monitor 23 from among the multiple candidates for ultrasound image U2.

[0052] Furthermore, as shown in Figure 12, for example, the display control unit 22 can highlight the portion CP corrected by the contour correction unit 26 within the corrected contour CC of the ultrasound image U2 using a different display method than the rest of the contour CC. The display control unit 22 can highlight the contour CC by, for example, displaying the portion CP corrected by the contour correction unit 26 with a dashed line, displaying it in a different color from the surrounding color, enclosing the corrected portion CP in a closed shape such as a circle, or displaying text such as "corrected portion" near the corrected portion CP. This allows the user to easily grasp the specific correction location in the contour CC.

[0053] Furthermore, when the contour correction unit 26 corrects the contour C of the cardiac chamber A shown in the ultrasound image U of the frame to be corrected based on ultrasound images U of frames before and after the ultrasound image U of the frame to be corrected, or ultrasound images U of frames that belong to a different period and are in the same phase as the ultrasound image U of the frame to be corrected, the display control unit 22 can display, for example as shown in Figure 13, an ultrasound image U of a frame different from the ultrasound image U of the frame to be corrected, which was referenced during the correction of contour C, as a correction reference image UR on the monitor 13.

[0054] In this process, the display control unit 22 can display the ultrasound image U with the uncorrected contour C superimposed and the ultrasound image U2 with the corrected contour CC superimposed as images to be corrected on the monitor 23. The user can easily confirm whether the contour CC has been properly corrected by comparing the ultrasound image U2 with the corrected contour CC superimposed with the correction reference image UR.

[0055] In this embodiment, each process is executed on any computer. Furthermore, any computer may execute these processes using a processor as hardware, a program as software, or a combination thereof. In that case, the processor is configured to work in cooperation with the program to execute the various processes in this embodiment, and can function as one of the units or means in this embodiment. Also, the execution order of the processes by the processor is not limited to the order described and may be changed as appropriate. Any computer may be a general-purpose computer, a computer designed for a specific purpose, a workstation, or any other system capable of executing each process.

[0056] The processor 32, which includes an image generation unit 21, a display control unit 22, a contour extraction unit 24, a contour correction unit 26, a measurement target extraction unit 27, a measurement unit 28, and a main unit control unit 29, may be composed of one or more hardware components, and the type of hardware is not limited. For example, the processor 32 can be composed of hardware such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a programmable logic device such as an FPGA (Field Programmable Gate Array), a dedicated circuit for executing a specific process such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). Furthermore, the type of hardware may be a combination of different types of hardware. When multiple hardware components are configured to execute one or more processes of a given processor, these multiple hardware components may reside in physically separate devices or in the same device. Also, in any embodiment, the order of each process performed by the processor is not limited to the order described above and may be changed as appropriate. The hardware is composed of electrical circuits (circuitry) that combine circuit elements such as semiconductor elements.

[0057] Furthermore, the program may be firmware or software such as microcode. Alternatively, the program may be, for example, a set of program modules, each function of which may be implemented by a processor configured to perform its respective function. The program may be program code or multiple code segments stored on one or more non-temporary computer-readable media (e.g., storage media or other storage). The program may be divided and stored on multiple non-temporary computer-readable media located in physically separate devices. Program code or code segments can represent any combination of procedures, functions, subprograms, routines, subroutines, modules, software packages, classes, or instructions, data structures, or program statements. Program code or code segments may be connected to other code segments or hardware circuits by sending and receiving information, data, arguments, parameters, or memory contents.

[0058] Next, the operation of the ultrasound diagnostic apparatus according to Embodiment 1 will be described with reference to the flowchart shown in Figure 14.

[0059] In step S1, the image acquisition unit 31 generates an ultrasound image U of the cardiac chamber A. At this time, under the control of the main unit control unit 29, the transmission and reception of ultrasound is started from multiple transducers of the transducer array 11 according to the drive signal from the pulser 41 of the transmitting and receiving circuit 12 of the ultrasound probe 1. The ultrasound echo from within the subject is received by multiple transducers of the transducer array 11, the received signal which is an analog signal is output to the amplification unit 42 for amplification, and then converted to AD by the AD conversion unit 43 to acquire the received data.

[0060] The beamformer 44 performs reception focus processing on this received data, and the resulting sound ray signal is sent to the image generation unit 21 of the main unit 2 of the device, where the image generation unit 21 generates an ultrasound image U representing the heart chamber A of the subject. At this time, the signal processing unit 45 of the image generation unit 21 performs attenuation correction according to the depth of the ultrasound reflection position and envelope detection processing on the sound ray signal, and the DSC 46 converts it into an image signal following the scanning method of a normal television signal, and the image processing unit 47 performs various necessary image processing such as gradation processing. The ultrasound image U generated in step S1 in this way is sent to the display control unit 22, the contour extraction unit 24 and the memory 25.

[0061] In step S2, the contour extraction unit 24 extracts the contour C of the heart chamber A from the ultrasound image U acquired in step S1, as shown in Figure 4. The contour extraction unit 24 can extract the contour C of the heart chamber A by, for example, using a trained model in machine learning that has learned the relationship between a large number of ultrasound images U and the contour C of the heart chamber A shown therein. The information of the contour C extracted in step S2 is sent to the display control unit 22 and the memory 25.

[0062] Furthermore, in step S2, the memory 25 stores the ultrasound image U acquired in step S1 and the information of the contour C of the cardiac chamber A extracted by the contour extraction unit 24, linking them together.

[0063] In step S3, the display control unit 22 displays the ultrasound image U, which has the contour C of the cardiac chamber A extracted in step S2 superimposed on it, on the monitor 23 in real time, as shown in Figure 4.

[0064] In step S4, the main unit control 29 determines whether or not to terminate the acquisition of the ultrasound image U. The main unit control 29 can determine to terminate the acquisition of the ultrasound image U if, for example, the user inputs an instruction to terminate the acquisition of the ultrasound image U via the input device 30. The main unit control 29 can also determine to continue acquiring the ultrasound image U if the user does not specifically input an instruction to terminate the acquisition of the ultrasound image U.

[0065] As long as it is determined in step S4 to continue acquiring ultrasound images U, the processes in steps S1 to S4 are repeated. This acquires multiple frames of ultrasound images U that are consecutive in time series and correspond to multiple heartbeats, and the contour C of the cardiac chamber A is extracted from each ultrasound image U. The ultrasound images U obtained in this way, along with the information of the contour C of the cardiac chamber A extracted from those ultrasound images U, are stored in memory 25. After that, if it is determined in step S4 to terminate the acquisition of ultrasound images U, the process proceeds to step S5.

[0066] In step S5, the contour correction unit 26 applies a correction process to the multiple contours C of the cardiac chamber A, which are extracted from each of the multiple ultrasound images U of multiple frames acquired by repeating steps S1 to S4 and stored in memory 25, so that the multiple contours C of the cardiac chamber A change smoothly over time.

[0067] The contour correction unit 26 can correct the contour C2 of cardiac chamber A in the ultrasound image U of the Nth frame extracted in step S2, for example as shown in Figures 5 and 6, so as to ensure consistency with the contours C1 and C3 of cardiac chamber A in the ultrasound images U of the N-1th and N+1th frames, which are the preceding and succeeding frames.

[0068] The contour correction unit 26 can, for example, acquire heart rate phase information based on the changes in multiple contours C of heart chamber A extracted in step S2, and by referring to the acquired heart rate phase information, correct the contour C of heart chamber A so as shown in Figures 7 and 8, that the positions of the contour C of heart chamber A corresponding to multiple ultrasound images U of the same phase in different heartbeat cycles are aligned with each other.

[0069] The contour correction unit 26 can also correct the contour C of the cardiac chamber A by referring to heart rate phase information, for example as shown in Figure 9, so as to align the positions of structures of interest that do not ideally shift in the ultrasound image U due to the heartbeat, such as the position of the cardiac apex D and the positions of the mitral valve roots M1 and M2, in ultrasound images U that are in the same phase but with different heartbeat cycles.

[0070] The contour correction unit 26 can also calculate an edge line E where the brightness difference of the ultrasound image U is maximum near the contour C of the cardiac chamber A extracted in step S2, as shown in Figure 10, and correct the contour C so that it overlaps with the edge line E.

[0071] In this way, the information of contour C corrected in step S5 is stored in memory 25. In step S5, since the contour C of cardiac chamber A extracted in step S2 is corrected in this way, even if any of the contours C of cardiac chamber A extracted in step S2 deviate from the actual contour C of cardiac chamber A, an accurate contour C can ultimately be obtained. Furthermore, since both the process of extracting the contour C of cardiac chamber A in step S2 and the process of correcting the contour C of cardiac chamber A in step S5 are completed solely by image analysis of the ultrasound image U, an accurate contour C can be obtained without requiring a complex device configuration or processing.

[0072] In the subsequent step S6, the measurement target extraction unit 27 extracts the ultrasound image U to be measured for cardiac function from the multiple ultrasound image U frames, based on the contour C of the cardiac chamber A extracted from the multiple ultrasound image U frames in step S2 and corrected in step S5. For example, when the ejection fraction of cardiac chamber A is measured as a measure of cardiac function, the ultrasound image U frames corresponding to at least one of the end-systolic and end-diastolic phases of the heart H are used as the measurement target. In this case, the measurement target extraction unit 27 can, for example, refer to heart rate phase information to extract the ultrasound image U frames corresponding to at least one of the end-systolic and end-diastolic phases of the heart H as the measurement target.

[0073] In step S7, the measurement unit 28 measures cardiac function using the ultrasound image U extracted in step S6. For example, when measuring the ejection fraction of cardiac chamber A as a measure of cardiac function, the measurement unit 28 can calculate the area enclosed by the contour C of cardiac chamber A in the ultrasound image U extracted in step S6, and calculate the ejection fraction of cardiac chamber A based on the calculated area. The cardiac function measurement results obtained in step S7 are sent to the display control unit 22 and the memory 25.

[0074] In step S8, if any of the contours C of the heart chamber A are corrected in step S5, the display control unit 22 displays, for example as shown in Figure 11, an ultrasound image U1 with the uncorrected contour C extracted in step S2 superimposed, an ultrasound image U2 with the corrected contour CC from step S5 superimposed, and the measurement results from step S7 on the monitor 23. The display control unit 22 can, for example, display on the monitor 23 an ultrasound image U2 and its corresponding ultrasound image U1 specified by the user via the input device 30 from among multiple ultrasound images U. The display control unit 22 can also display on the monitor 23 an ultrasound image U2 extracted by the measurement target extraction unit 27 and the ultrasound image U1 corresponding to that ultrasound image U2.

[0075] The display control unit 22 can also, for example as shown in Figure 12, highlight the portion CP corrected by the contour correction unit 26 within the corrected contour CC of the ultrasound image U2 using a different display mode than the rest of the contour CC. This allows the user to easily identify the specific corrected area in the contour CC. If the contour C is not corrected in step S5, the display control unit 22 can display only the ultrasound image U with the contour C extracted in step S2 superimposed on it on the monitor 23.

[0076] In step S5, if the contour C of the cardiac chamber A shown in the ultrasound image U of the frame to be corrected is corrected based on the ultrasound images U of the frames before and after the ultrasound image U of the frame to be corrected, or the ultrasound image U of a frame that belongs to a different period than the period of the heartbeat to which the ultrasound image U of the frame to be corrected belongs and is in the same phase, the display control unit 22 can display the ultrasound image U of a frame different from the ultrasound image U of the frame to be corrected, which was referenced during the correction of the contour C, as a correction reference image UR on the monitor 13, for example, as shown in Figure 13.

[0077] In this process, the display control unit 22 can display the ultrasound image U with the uncorrected contour C superimposed and the ultrasound image U2 with the corrected contour CC superimposed as images to be corrected on the monitor 23. The user can easily confirm whether the contour CC has been properly corrected by comparing the ultrasound image U2 with the corrected contour CC superimposed with the correction reference image UR.

[0078] Once the process in step S8 is completed, the operation of the ultrasound diagnostic device shown in Figure 14 is finished.

[0079] As described above, according to the ultrasound diagnostic apparatus of Embodiment 1, the contour extraction unit 24 extracts the contour C of the cardiac chamber A from each of the multiple frames of ultrasound images U, the contour correction unit 26 performs correction processing on the multiple contours C of cardiac chamber A extracted from the multiple frames of ultrasound images U so that the contours C of cardiac chamber A change smoothly over time, the display control unit 22 displays the ultrasound image U with the contours C of cardiac chamber A extracted for each frame superimposed on the monitor 23 in real time, and if the contour C of cardiac chamber A is corrected thereafter, the ultrasound image U with the corrected contours CC of cardiac chamber A superimposed is displayed on the monitor 23, thus providing support for accurately measuring cardiac function with a simple device configuration.

[0080] Although it is explained that the transmitting / receiving circuit 12 is provided in the ultrasonic probe 1, the transmitting / receiving circuit 12 may also be provided in the main body of the device 2. Furthermore, although it is explained that the image generation unit 21 is provided in the main body 2 of the device, the image generation unit 21 may also be provided in the ultrasonic probe 1.

[0081] The main unit 2 of the device may be a stationary type, a portable type that is easy to carry, or a handheld type, for example, composed of a smartphone or tablet computer. Thus, the type of equipment that makes up the main unit 2 is not particularly limited.

[0082] It has been explained that the contour correction unit 26 corrects the contour C of the cardiac chamber A in the ultrasound image U to be corrected using two ultrasound images U, that is, one frame before and one frame after the ultrasound image U to be corrected. However, for example, it is also possible to correct the contour C of the cardiac chamber A using two frames before and after, that is, a total of four ultrasound images U, two frames before and two frames after.

[0083] The number of ultrasound images U used as reference during correction can also be changed for the diastole and systole phases of the heart. For example, since the left ventricle changes shape faster in diastole than in systole, one ultrasound image U from before and after the diastole can be used in diastole, and two ultrasound images U from before and after the systole can be used in systole.

[0084] An example is described in which the contour correction unit 26 corrects the contour C of the cardiac chamber A using three ultrasound images U with different heartbeat periods and in the same phase. However, it is also possible to use two ultrasound images U with different heartbeat periods and in the same phase, or to use four or more ultrasound images U with different heartbeat periods and in the same phase.

[0085] The contour extraction unit 24 can also calculate a confidence score for each pixel on the contour C of the heart chamber A when extracting the contour C from the ultrasound image U. The confidence score is an indicator of how likely it is that the pixel accurately represents the contour C of the heart chamber A. A higher confidence score indicates that the pixel accurately represents the contour C of the heart chamber A, while a lower confidence score indicates that the pixel may not accurately represent the contour C of the heart chamber A. The contour extraction unit 24 can calculate the confidence score, for example, by using a trained machine learning model that has learned the relationship between a large number of ultrasound images U of the heart chamber A, the contour C of the heart chamber A, and the confidence score of each pixel on that contour C as training data.

[0086] When the contour extraction unit 24 calculates confidence for pixels on the contour C of the cardiac chamber A, the contour correction unit 26 can also identify low-confidence regions in each ultrasound image U where the confidence level is lower than a predetermined threshold, and correct only the contour C in the identified low-confidence regions.

[0087] Embodiment 2 In Embodiment 1, the contour C of the cardiac chamber A is corrected after the acquisition of multiple frames of ultrasound images U is completed. However, the ultrasound diagnostic device can also correct the contour C each time the contour C of the cardiac chamber A is extracted.

[0088] Since the ultrasound diagnostic apparatus of Embodiment 2 has the same apparatus configuration as the ultrasound diagnostic apparatus of Embodiment 1 shown in Figure 1, a description of the apparatus configuration will be omitted, and its operation will be explained using the flowchart in Figure 15. The flowchart in Figure 15 includes steps S1, S2, S5, S7, and S8 in the flowchart of Figure 14 in Embodiment 1. Therefore, a detailed explanation of these steps will be omitted.

[0089] First, in step S1, the image acquisition unit 31 acquires an ultrasound image U of the heart chamber A of the subject. In the following step S2, the contour extraction unit 24 extracts the contour C of heart chamber A from the ultrasound image U acquired in step S1.

[0090] Next, in step S5, the contour correction unit 26 performs a correction process on the contour C of the cardiac chamber A extracted in step S2. At this point, only one frame of ultrasound image U has been acquired, so if the contour correction unit 26 were to perform a correction of contour C using multiple ultrasound images U, such as correcting contour C using ultrasound images U from preceding and succeeding frames, or correcting contour C using ultrasound images U from frames with different heartbeat cycles but in the same phase, the processing in step S5 can be skipped.

[0091] Next, in step S9, if the contour C of cardiac chamber A was corrected in step S5, the display control unit 22 displays on the monitor 23 an ultrasound image U with the contour C of cardiac chamber A extracted in step S2 superimposed, and an ultrasound image U with the contour CC of cardiac chamber A corrected in step S5 superimposed. If the contour C was not corrected in step S5, the display control unit 22 can display on the monitor 23 only an ultrasound image U with the contour C extracted in step S2 superimposed.

[0092] Next, in step S10, the measurement target extraction unit 27 extracts the ultrasound image U that is the target of cardiac function measurement from the ultrasound image U acquired up to that point, and determines whether or not the ultrasound image U that is the target of cardiac function measurement was extracted based on the extraction result. At this point, only one frame of ultrasound image U has been acquired, so the ultrasound image U that is the target of cardiac function measurement was not extracted, and it is determined that the ultrasound image U that is the target of cardiac function measurement was not extracted.

[0093] As long as it is determined that the ultrasound image U to be used for measuring cardiac function could not be extracted, steps S1, S2, S5, S9, and S10 are repeated. In step S1 of this repetition, multiple frames of ultrasound image U are acquired. In step S2 of the repetition, the contour C of cardiac chamber A is extracted from each of the multiple frames of ultrasound image U. Furthermore, each time step S5 is performed, a correction process is applied to the contour C of cardiac chamber A in the multiple frames of ultrasound image U acquired up to that point. This step S5 makes it possible to obtain an accurate contour C of cardiac chamber A.

[0094] If it is determined in step S10 that an ultrasound image U for measuring cardiac function has been extracted, the process proceeds to step S7. In step S7, the measurement unit 28 measures cardiac function based on the contour C of the cardiac chamber A in the ultrasound image U extracted in step S10.

[0095] In the subsequent step S8, the display control unit 22 displays, for example as shown in Figure 11, an ultrasound image U1 with the contour C of the cardiac chamber A extracted in step S2 superimposed, an ultrasound image U2 with the corrected contour CC superimposed in step S5, and the measurement results of step S7 on the monitor 23.

[0096] In step S11, the main unit control 29 determines whether or not to terminate the acquisition of the ultrasound image U. The main unit control 29 can determine to terminate the acquisition of the ultrasound image U if, for example, the user inputs an instruction to terminate the acquisition of the ultrasound image U via the input device 30. In this case, the main unit control 29 can determine to continue acquiring the ultrasound image U if the user does not specifically input an instruction to input the ultrasound image U via the input device 30.

[0097] As long as it is determined in step S11 to continue acquiring the ultrasound image U, the processes in steps S1, S2, S5, S9, S10, S7, S8, and S11 are repeated. When it is determined in step S11 to finish acquiring the ultrasound image U, the operation of the ultrasound diagnostic device according to the flowchart in Figure 15 is completed.

[0098] From the above, according to the ultrasound diagnostic apparatus of Embodiment 2, even when the contour correction unit 26 corrects the contour C of cardiac chamber A each time the contour extraction unit 24 extracts the contour C of cardiac chamber A, it is possible to provide support for accurately measuring cardiac function with a simple device configuration.

[0099] Embodiment 3 In embodiments 1 and 2, the correction of the contour C of the cardiac chamber A is performed on all of the ultrasound images U across multiple frames. However, the ultrasound diagnostic device can also correct only the ultrasound images U of a specific frame.

[0100] Figure 16 shows the configuration of the ultrasound diagnostic apparatus of Embodiment 3. The ultrasound diagnostic apparatus of Embodiment 3 is equipped with a device body 2A in place of the device body 2 shown in Figure 1 of the ultrasound diagnostic apparatus of Embodiment 1. The device body 2A in Embodiment 3 is equipped with an image selection unit 51 in place of the device body 2 in Embodiment 1, and a device control unit 29A in place of the main unit control unit 29.

[0101] In the main unit 2A of the device, the image selection unit 51 is connected to the memory 25. The contour correction unit 26 and the main unit control unit 29A are connected to the image selection unit 51. Furthermore, the image generation unit 21, display control unit 22, contour extraction unit 24, contour correction unit 26, measurement target extraction unit 27, measurement unit 28, main unit control unit 29A and the image selection unit 51 constitute the processor 32A for the main unit 2A of the device.

[0102] The image selection unit 51 selects an ultrasound image U from multiple frames of ultrasound images U acquired by the image acquisition unit 31 that is to be corrected by the contour correction unit 26 for the contour C of the cardiac chamber A. The image selection unit 51 can select, for example, an ultrasound image U from among multiple frames of ultrasound images U that corresponds to the end of diastole or end of systole, or an ultrasound image U that may be extracted by the measurement target extraction unit 27 as a target for measuring cardiac function, as a target for correction.

[0103] The image selection unit 51 can, for example, select an ultrasound image U selected by the user via the input device 30 as the image to be corrected.

[0104] The image selection unit 51 can acquire heart rate phase information based on the contour C of heart chamber A extracted by the contour extraction unit 24, and can also select an ultrasound image U to be corrected, such as an ultrasound image U corresponding to the end of diastole or end of systole, based on the acquired heart rate phase information. The image selection unit 51 can, for example, similar to the measurement target extraction unit 27, calculate the volume of heart chamber A based on multiple contours C of heart chamber A extracted by the contour extraction unit 24 for multiple frames of ultrasound image U, and acquire heart rate phase information based on the time-series change in the volume of heart chamber A.

[0105] The contour correction unit 26 performs correction processing on the contour C of the cardiac chamber A in the ultrasound image U selected as the correction target by the image selection unit 51. Instead of correcting the contour C of the cardiac chamber A for all frames of ultrasound image U acquired by the image acquisition unit 31, the contour correction unit 26 corrects only the ultrasound image U selected by the image selection unit 51. This reduces the computational load on the contour correction unit 26 and allows the correction processing of contour C to be completed more quickly.

[0106] As described above, according to the ultrasound diagnostic apparatus of Embodiment 3, the image selection unit 51 selects an ultrasound image U from multiple frames of ultrasound images U to be corrected by the contour correction unit 26 for the contour C of the cardiac chamber A, and the contour correction unit 26 performs contour correction processing on the ultrasound image U selected by the image selection unit 51 for the contour C of the cardiac chamber A. This reduces the computational load on the contour correction unit 26 and allows for faster completion of cardiac function measurement.

[0107] Furthermore, after the display control unit 22 displays the ultrasound image U with the corrected contour C of cardiac chamber A superimposed on it on the monitor 23, the contour correction unit 26 can correct the contour C of cardiac chamber A again when a new ultrasound image U is selected by the user via the input device 30. When the contour C of cardiac chamber A in the ultrasound image U selected by the image selection unit 51 is corrected by the contour correction unit 26, it may be found that the appropriate ultrasound image U for measurement is another ultrasound image U. Therefore, by correcting the contour C of cardiac chamber A in this ultrasound image U, the measurement unit 28 can accurately measure cardiac function. [Explanation of Symbols]

[0108] 1 Ultrasound probe, 2 Main unit, 11 Transducer array, 12 Transmit / receive circuit, 21 Image generation unit, 22 Display control unit, 23 Monitor, 24 Contour extraction unit, 25 Memory, 26 Contour correction unit, 27 Measurement target extraction unit, 28 Measurement unit, 29, 29A Main unit control unit, 30 Input device, 31 Image acquisition unit, 32, 32A Processor, 41 Pulsar, 42 Amplifier unit, 43 AD conversion unit, 44 Beamformer, 45 Signal processing unit, 46 DSC, 47 Image processing unit, 51 Image selection unit, 4C Apical four-chamber section, A Cardiac chamber, C, C1~C6, CC Contour, CP Part, D Apex, E Edge line, M1, M2 Mitral valve base, U, U1, U2 Ultrasound image, UR Correction reference image.

Claims

1. Ultrasound probe and Monitor and, An image acquisition unit that acquires multiple frames of ultrasound images as moving images of the subject's heart by transmitting and receiving ultrasound beams using the ultrasound probe, A contour extraction unit extracts the contours of the cardiac chambers from each of the multiple frames of ultrasound images acquired by the image acquisition unit, A contour correction unit performs a correction process on the multiple contours of the heart chambers extracted by the contour extraction unit from the multiple frames of ultrasound images so that the multiple contours of the heart chambers change smoothly over time. A display control unit displays the ultrasound image on the monitor in real time, with the contours of the heart chambers extracted by the contour extraction unit superimposed on each frame, and also displays the ultrasound image on the monitor with the contours of the heart chambers superimposed after being corrected by the contour correction unit. An ultrasound diagnostic device equipped with the following features.

2. The ultrasound diagnostic apparatus according to claim 1, further comprising a measurement target image extraction unit that extracts the ultrasound image to be measured from the plurality of frames of ultrasound images based on the contour of the heart chamber extracted by the contour extraction unit.

3. The ultrasound diagnostic apparatus according to claim 1, wherein the contour correction unit corrects the contour of the cardiac chamber extracted by the contour extraction unit to ensure consistency with the contour of the cardiac chamber in the front and rear frames.

4. The ultrasound diagnostic apparatus according to claim 1, wherein the contour correction unit corrects the contour of the cardiac chamber based on positional information of the characteristic structure of the cardiac chamber.

5. The contour correction unit, Based on the contours of the heart chambers extracted by the contour extraction unit, heart rate phase information is acquired. The ultrasound diagnostic apparatus according to claim 1, which corrects the contour of the cardiac chambers so as to align the positions of the contours of the cardiac chambers corresponding to a plurality of ultrasound images of the same phase in different cardiac cycles by referring to the cardiac phase information.

6. The contour correction unit, The edge line that has the maximum brightness difference in the vicinity of the contour of the heart chamber extracted by the contour extraction unit is calculated. The ultrasound diagnostic apparatus according to claim 1, which corrects the contour of the cardiac chamber so that the contour of the cardiac chamber aligns with the edge line.

7. The ultrasound diagnostic apparatus according to claim 1, wherein the display control unit highlights the portion of the ultrasound image related to the correction performed by the contour correction unit.

8. The ultrasound diagnostic apparatus according to claim 1, further comprising an image selection unit that selects from the plurality of frames of ultrasound images the ultrasound image to be used for contour correction of the cardiac chamber by the contour correction unit.

9. Equipped with an input device for the user to perform input operations, The ultrasound diagnostic apparatus according to claim 8, wherein the image selection unit selects the ultrasound image selected by the user via the input device as the correction target.

10. The ultrasound diagnostic apparatus according to claim 9, wherein the contour correction unit corrects the contour of the heart chamber again when the user selects a new ultrasound image to be corrected via the input device after the display control unit has displayed the corrected contour of the heart chamber superimposed on the ultrasound image on the monitor.

11. The aforementioned image selection unit, Based on the contours of the heart chambers extracted by the contour extraction unit, heart rate phase information is acquired. The ultrasound diagnostic apparatus according to claim 8, which selects the ultrasound image to be corrected based on the acquired heart rate phase information.

12. The ultrasound diagnostic apparatus according to claim 2, further comprising a measurement unit that measures cardiac function using the ultrasound image to be measured, which is extracted by the measurement target image extraction unit and on which the contours of the cardiac chambers corrected by the contour correction unit are superimposed.

13. The ultrasound diagnostic apparatus according to claim 12, wherein the display control unit displays the measurement results from the measurement unit together with the ultrasound image on which the contours of the heart chambers extracted by the contour extraction unit are superimposed.

14. The ultrasound diagnostic apparatus according to claim 1, wherein the contour correction unit corrects the extracted contour of the cardiac chamber each time the contour extraction unit extracts the contour of the cardiac chamber.

15. By transmitting and receiving ultrasound beams using an ultrasound probe, multiple frames of ultrasound images are obtained as moving images of the subject's heart. The contours of the cardiac chambers are extracted from each of the acquired multiple frames of ultrasound images. Correction processing is applied to the multiple contours of the heart chambers extracted from the multiple frames of ultrasound images so that they change smoothly over time. A display control unit that displays the ultrasound image on a monitor in real time, with the contours of the heart chambers extracted for each frame superimposed, and also displays the ultrasound image on the monitor with the corrected contours of the heart chambers superimposed. A control method for an ultrasound diagnostic device equipped with the following features.

Images