Region-of-interest tracking method for myocardial quantitative analysis and ultrasonic imaging system

Abstract

The invention discloses a region-of-interest tracking method for myocardial quantitative analysis and an ultrasonic imaging system. According to the region-of-interest tracking method for myocardial quantitative analysis, provided by the invention, the first region-of-interest and the second region-of-interest which are used for representing the myocardial contour and have different shapes are respectively determined in the first key frame and the second key frame of the multi-frame myocardial ultrasound image of the target cardiac cycle; and further based on the first region-of-interest and the second region-of-interest, determining a third region-of-interest which is used for representing the myocardial contour and is different from the first region-of-interest and the second region-of-interest in shape in the transition frame, thereby realizing rapid and flexible adaptation of the shape of the region-of-interest and the myocardial contour. The accuracy of myocardial quantitative analysis is improved.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic imaging technology, and particularly to a method for tracking regions of interest for myocardial quantitative analysis and an ultrasonic imaging system. Background Art

[0002] In the research of myocardial perfusion, the normality of myocardial tissue perfusion can be used to judge whether the oxygen supply to cardiomyocytes is sufficient. Under normal physiological conditions, the oxygen demand of tissues determines the blood flow of tissues. Therefore, blood flow is an important parameter for judging heart diseases. At present, the detection of microvascular perfusion based on contrast agents is the most direct and accurate method for evaluating myocardial perfusion.

[0003] Myocardial contrast focuses on the process of fragmentation and reperfusion. Myocardial contrast quantitative analysis is to select ROIs in myocardial two-dimensional contrast images, draw time-intensity curves within the ROIs, and analyze the time-intensity curves within the ROIs to quantitatively evaluate the myocardial perfusion level. Due to the periodic movement of the heart, the selected ROIs need to be motion-compensated, and at the same time, the selected ROIs need to contain as much myocardial tissue as possible to reflect the blood perfusion in the myocardium.

[0004] However, currently, the in-machine quantitative analysis plug-ins for myocardial quantitative analysis usually use ROIs in the shape of ellipses or squares for myocardial quantitative analysis. However, throughout the cardiac cycle, the shape of the ROI never changes, only the position will be translated, which does not conform to the torsional movement law of the myocardium. Summary of the Invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description section. The Summary of the Invention section of the present invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0006] A method for tracking regions of interest in myocardial quantitative analysis according to a first aspect of an embodiment of the present application includes: obtaining multiple frames of myocardial ultrasound images of a target cardiac cycle; determining a first key frame and a second key frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle; determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame, wherein the shape of the first region of interest is different from that of the second region of interest; obtaining at least one third region of interest for representing the myocardial contour in at least one transition frame between the first key frame and the second key frame based on the first region of interest and the second region of interest, wherein at least two of the multiple third regions of interest are different in shape from each other or at least one of the third regions of interest is different in shape from the first region of interest or the second region of interest, wherein the transition frame is at least one frame other than the first key frame and the second key frame in the multiple frames of myocardial ultrasound images and one transition frame corresponds to one third region of interest; obtaining quantitative parameters of the change of the myocardium over time in the region of interest corresponding to the target cardiac cycle according to the first region of interest, the second region of interest, and at least one of the third regions of interest.

[0007] A second aspect of the embodiments of the present application provides a method for tracking regions of interest in myocardial quantitative analysis, including: obtaining multiple frames of myocardial ultrasound images during the myocardial contrast reperfusion process of multiple cardiac cycles; determining a first key frame and a second key frame in multiple frames of myocardial ultrasound images of a target cardiac cycle, where the target cardiac cycle is one of the multiple cardiac cycles; determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame, where the shapes of the first region of interest and the second region of interest are different; determining the first key frame and the second key frame corresponding to the phases of other cardiac cycles based on the phases of the first key frame and the second key frame in the target cardiac cycle, where the other cardiac cycles are at least one of the multiple cardiac cycles except the target cardiac cycle; synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of the other cardiac cycles; obtaining at least one third region of interest for representing the myocardial contour in at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or the other cardiac cycles based on the first region of interest, the second region of interest, and the target cardiac cycle and / or the other cardiac cycles corresponding thereto, where at least two of the multiple third regions of interest are different in shape from each other or at least one of the third regions of interest is different in shape from the first region of interest or the second region of interest, where the transition frame is at least one frame other than the first key frame and the second key frame in multiple frames of myocardial ultrasound images of the target cardiac cycle and / or the other cardiac cycles, and one transition frame corresponds to one third region of interest; obtaining a curve of the change in the intensity of the contrast agent over time in the region of interest corresponding to the target cardiac cycle and / or the other cardiac cycles based on the first region of interest, the second region of interest, and at least one third region of interest corresponding to the target cardiac cycle and / or the other cardiac cycles.

[0008] A third aspect of the embodiments of the present application provides an ultrasound imaging system, including: an ultrasound probe; a transmit / receive circuit for exciting the ultrasound probe to transmit ultrasonic waves to the myocardium and controlling the ultrasound probe to receive the echoes of the ultrasonic waves to obtain echo signals of the ultrasonic waves; a processor for performing the steps of the method for tracking regions of interest in myocardial quantitative analysis as described above.

[0009] According to the method for tracking regions of interest in myocardial quantitative analysis and the ultrasonic imaging system provided by the present application, by respectively determining a first region of interest and a second region of interest with different shapes for characterizing the myocardial contour in a first key frame and a second key frame of multiple frames of myocardial ultrasonic images in a target cardiac cycle, and further determining a third region of interest with a shape different from that of the first region of interest and the second region of interest for characterizing the myocardial contour in an intermediate frame based on the first region of interest and the second region of interest, rapid and flexible adaptation of the shape of the region of interest to the myocardial contour is achieved, and the accuracy of myocardial quantitative analysis is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following drawings of the present invention are used as part of the present invention to understand the present invention. The embodiments of the present invention shown in the drawings and their descriptions are used to explain the principles of the present invention.

[0011] In the drawings:

[0012] Figure 1 A schematic block diagram of an ultrasonic imaging system according to an embodiment of the present application is shown;

[0013] Figure 2 A schematic diagram of obtaining control points of an intermediate frame by interpolation for a region of interest according to an embodiment of the present application is shown;

[0014] Figure 3 A flowchart of a method for tracking regions of interest in myocardial quantitative analysis according to an embodiment of the present application is shown;

[0015] Figure 4 A flowchart of a method for tracking regions of interest in myocardial quantitative analysis according to another embodiment of the present application is shown. DETAILED DESCRIPTION

[0016] In the following description, numerous specific details are given to provide a more thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without one or more of these details. In other instances, well-known features have not been described in order to avoid obscuring the present invention.

[0017] It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete, and to fully convey the scope of the present invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for clarity. Like reference numerals refer to like elements throughout.

[0018] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the related listed items.

[0019] To fully understand the present invention, detailed steps and detailed structures will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention may also have other embodiments.

[0020] Next, first refer to Figure 1 to describe an ultrasonic imaging system according to an embodiment of the present application, Figure 1 which shows a schematic structural block diagram of an ultrasonic imaging system 100 according to an embodiment of the present application.

[0021] As Figure 1 shown, the ultrasonic imaging system 100 includes an ultrasonic probe 110, a transmitting circuit 112, a receiving circuit 114, a processor 116, and a display 118. Further, the ultrasonic imaging system may also include a transmit / receive selection switch 120 and a beam synthesis module 122. The transmitting circuit 112 and the receiving circuit 114 may be connected to the ultrasonic probe 110 through the transmit / receive selection switch 120.

[0022] The ultrasonic probe 110 includes a plurality of transducer elements. The plurality of transducer elements may be arranged in a row to form a linear array, or arranged in a two-dimensional matrix to form a planar array. The plurality of transducer elements may also form a convex array. The transducer elements are used to emit ultrasonic waves according to the excitation electrical signals, or convert the received ultrasonic waves into electrical signals. Therefore, each transducer element can be used to realize the mutual conversion between the electrical pulse signal and the ultrasonic wave, so as to emit ultrasonic waves to the tissue in the target area of the object to be measured, and can also be used to receive the ultrasonic wave echoes reflected by the tissue. During ultrasonic detection, it is possible to control which transducer elements are used to emit ultrasonic waves and which transducer elements are used to receive ultrasonic waves through the transmit sequence and the receive sequence, or control the transducer elements to be used to emit ultrasonic waves or receive the echoes of ultrasonic waves in different time slots. The transducer elements participating in the ultrasonic wave emission can be simultaneously excited by electrical signals to simultaneously emit ultrasonic waves; or, the transducer elements participating in the ultrasonic beam emission can also be excited by a plurality of electrical signals with a certain time interval to continuously emit ultrasonic waves with a certain time interval.

[0023] During the ultrasonic imaging process, the transmitting circuit 112 sends the delayed and focused transmitting pulses to the ultrasonic probe 110 through the transmit / receive selection switch 120. The ultrasonic probe 110 is excited by the transmitting pulses to emit an ultrasonic beam to the tissue in the target area of the object to be measured. After a certain time delay, it receives the ultrasonic echo with tissue information reflected from the tissue in the target area and reconverts this ultrasonic echo into an electrical signal. The receiving circuit 114 receives the electrical signal generated by the conversion of the ultrasonic probe 110, obtains the ultrasonic echo signal, and sends these ultrasonic echo signals to the beam synthesis module 122. The beam synthesis module 122 performs processing such as focusing delay, weighting, and channel summation on the ultrasonic echo data, and then sends it to the processor 116. The processor 116 performs processing such as signal detection, signal enhancement, data conversion, and logarithmic compression on the ultrasonic echo signal to form an ultrasonic image. The ultrasonic image obtained by the processor 116 can be displayed on the display 118 or stored in the memory 124.

[0024] Optionally, the processor 116 can be implemented as software, hardware, firmware, or any combination thereof, and can use one or more application specific integrated circuits (ASICs), one or more general integrated circuits, one or more microprocessors, one or more programmable logic devices, or any combination of the foregoing circuits and / or devices, or other suitable circuits or devices. Moreover, the processor 116 can control other components in the ultrasonic imaging system 100 to perform the corresponding steps of the methods in various embodiments of this specification.

[0025] The display 118 is connected to the processor 116. The display 118 can be a touch display screen, a liquid crystal display screen, etc.; or, the display 118 can be an independent display such as a liquid crystal display or a television outside the ultrasonic imaging system 100; or, the display 118 can be the display screen of an electronic device such as a smart phone or a tablet computer, etc. Among them, the number of displays 118 can be one or more.

[0026] The display 118 can display the ultrasonic image obtained by the processor 116. In addition, while displaying the ultrasonic image, the display 118 can also provide a graphical interface for human-computer interaction to the user. One or more controlled objects are set on the graphical interface, and the user is provided with a man-machine interaction device to input operation instructions to control these controlled objects, so as to perform corresponding control operations. For example, an icon is displayed on the graphical interface, and the icon can be operated by using the man-machine interaction device to perform a specific function, such as drawing a region of interest box on the ultrasonic image, etc.

[0027] Optionally, the ultrasonic imaging system 100 may further include other human-machine interaction devices other than the display 118, which are connected to the processor 116. For example, the processor 116 may be connected to the human-machine interaction device through an external input / output port, and the external input / output port may be a wireless communication module, a wired communication module, or a combination of both. The external input / output port may also be implemented based on USB, bus protocols such as CAN, and / or wired network protocols, etc.

[0028] Among them, the human-machine interaction device may include an input device for detecting user input information. The input information may be, for example, a control instruction for the ultrasonic emission / reception timing, an operation input instruction for drawing points, lines, or frames on the ultrasonic image, or may also include other instruction types. The input device may include one or a combination of multiple of a keyboard, a mouse, a roller, a trackball, a mobile input device (such as a mobile device with a touch display screen, a mobile phone, etc.), a multi-functional knob, and so on. The human-machine interaction device may also include an output device such as a printer.

[0029] The ultrasonic imaging system 100 may further include a memory 124 for storing instructions executed by the processor, storing received ultrasonic echoes, storing ultrasonic images, and so on. The memory may be a flash card, a solid-state memory, a hard disk, etc. It may be a volatile memory and / or a non-volatile memory, a removable memory and / or a non-removable memory, etc.

[0030] It should be understood that Figure 1 The components included in the illustrated ultrasonic imaging system 100 are only illustrative, and it may include more or fewer components. This application is not limited thereto.

[0031] Next, with reference to Figure 3 Describe the method for tracking the region of interest in myocardial quantitative analysis proposed in the embodiments of the present application. Figure 3 It is a schematic flowchart of a method 300 for tracking the region of interest in myocardial quantitative analysis according to an embodiment of the present application. Specifically, the method 300 for tracking the region of interest in myocardial quantitative analysis according to an embodiment of the present application is applied to Figure 1 the illustrated ultrasonic imaging system 100, and the ultrasonic imaging system 100 includes an ultrasonic probe 110 and a processor 116, and the processor 116 performs the following steps:

[0032] In step S310, obtain multiple frames of myocardial ultrasonic images of a target cardiac cycle;

[0033] In step S320, determine a first key frame and a second key frame in the multiple frames of myocardial ultrasonic images of the target cardiac cycle;

[0034] In step S330, a first region of interest (ROI) representing the myocardial contour is determined based on the first key frame, and a second ROI representing the myocardial contour is determined based on the second key frame, where the shape of the first ROI is different from that of the second ROI.

[0035] In step S340, at least one third ROI for representing the myocardial contour is obtained from at least one transitional frame between the first key frame and the second key frame based on the first ROI and the second ROI, where at least two of the multiple third ROIs are different from each other in shape or at least one of the third ROIs is different in shape from the first ROI or the second ROI, and the transitional frame is at least one frame other than the first key frame and the second key frame in the multiple myocardial ultrasound images, and one transitional frame corresponds to one third ROI.

[0036] In step S350, quantitative parameters of the myocardium changing over time in the ROI corresponding to the target cardiac cycle are obtained according to the first ROI, the second ROI, and at least one third ROI.

[0037] After determining the key frames of the cardiac cycle in the movie file, the ROI tracking method 300 for myocardial quantitative analysis according to the embodiments of the present application can further determine the ROIs representing the myocardial contour of the transitional frames between the key frames on the basis of the ROIs representing the myocardial contour of the key frames, so that the adaptation of the ROI shape to the myocardial contour can be realized more quickly and flexibly during myocardial quantitative analysis, and the accuracy of myocardial quantitative analysis is improved.

[0038] In step S310, multiple myocardial ultrasound images of the target cardiac cycle are obtained. Exemplarily, obtaining multiple myocardial ultrasound images of the target cardiac cycle includes: obtaining multiple myocardial ultrasound images of multiple cardiac cycles; and determining the target cardiac cycle among the multiple cardiac cycles, where the target cardiac cycle is one cardiac cycle among the multiple cardiac cycles.

[0039] In one embodiment, electrocardiogram (ECG) data can be obtained, and the cardiac cycle can be determined based on the ECG data. And through Figure 1 the ultrasonic imaging system 100 as shown, during the scanning process, the transmitting circuit 112 sends a group of transmit pulses with delayed focusing to the ultrasonic probe 110 to stimulate the ultrasonic probe 110 to emit ultrasonic waves towards the myocardium. After the receiving circuit 114 controls the ultrasonic probe 110 to receive the ultrasonic echo reflected by the target object, it converts the ultrasonic echo into an electrical signal. The myocardial ultrasound images obtained by the ultrasonic imaging system 100 include one or more of contrast-enhanced ultrasound images, B-mode images, color Doppler images, super-resolution images, and the present application does not limit this.

[0040] In step S320, a first key frame and a second key frame are determined from multiple frames of myocardial ultrasound images of a target cardiac cycle. Exemplarily, an end-diastolic frame is determined from multiple frames of myocardial ultrasound images of a target cardiac cycle, and the end-diastolic frame serves as the first key frame; a end-systolic frame is determined from multiple frames of myocardial ultrasound images of a target cardiac cycle, and the end-systolic frame serves as the second key frame.

[0041] In one embodiment, since the myocardial blood volume is different in diastole and systole, the blood volume of the myocardium reaches the maximum or nearly the maximum at the end of diastole and reaches the minimum or nearly the minimum at the end of systole, and the shape of the myocardial contour may change significantly between the end of diastole and the end of systole; in addition, the results of myocardial quantitative analysis for the end of diastole and the end of systole are also worthy of special attention. For example, in the case of microcirculation disorders, only the data at the end of diastole can be concerned, and in the case of myocardial ischemia, only the data at the end of systole can be concerned. It should be noted that selecting the end-diastolic frame and the end-systolic frame as the first key frame and the second key frame of the target cardiac cycle is only exemplary. Other frames can be selected as key frames, or more key frames can be selected on the basis of taking the end-diastolic frame as the first key frame and the end-systolic frame as the second key frame.

[0042] In step S330, a first region of interest (ROI) characterizing the myocardial contour is determined based on the first key frame, and a second ROI characterizing the myocardial contour is determined based on the second key frame, wherein the shapes of the first ROI and the second ROI are different.

[0043] Exemplarily, determining a first ROI characterizing the myocardial contour based on the first key frame and a second ROI characterizing the myocardial contour based on the second key frame includes: in response to a user's tracing operation, obtaining a first contour line in the first key frame, and determining the first ROI characterizing the myocardial contour based on the first contour line; in response to a user's tracing operation, obtaining a second contour line in the second key frame, and determining the second ROI characterizing the myocardial contour based on the second contour line.

[0044] In one embodiment, in the first key frame (such as the end-diastolic key frame), the user manually draws the endocardial contour line and the epicardial contour line as the first contour line for the first ROI characterizing the myocardial contour; in the second key frame (such as the end-systolic key frame), the user manually draws the endocardial contour line and the epicardial contour line as the second contour line for the second ROI characterizing the myocardial contour. In addition, one or more segment lines may be included between the endocardial contour line and the epicardial contour line. Preferably, the one or more segment lines are perpendicular or nearly perpendicular to the endocardial contour line.

[0045] Exemplarily, determining a first region of interest (ROI) representing the myocardial contour based on a first key frame and determining a second ROI representing the myocardial contour based on a second key frame includes: automatically determining a plurality of first contour points in the first key frame and automatically determining a plurality of second contour points in the second key frame; in response to a user's tracing operation on the plurality of first contour points, obtaining a first contour line in the first key frame, and determining the first ROI representing the myocardial contour based on the first contour line; in response to a user's tracing operation on the plurality of second contour points, obtaining a second contour line in the second key frame, and determining the second ROI representing the myocardial contour based on the second contour line.

[0046] In one embodiment, in the first key frame (such as the end-diastolic key frame), a plurality of first contour points are automatically generated. The first contour points include endocardial contour points and epicardial contour points. Based on the automatically generated endocardial contour points and epicardial contour points, the user manually draws an endocardial contour line and an epicardial contour line as the first contour line for representing the first ROI of the myocardial contour; in the second key frame (such as the end-systolic key frame), a plurality of second contour points are automatically generated. The second contour points include endocardial contour points and epicardial contour points. Based on the automatically generated endocardial contour points and epicardial contour points, the user manually draws an endocardial contour line and an epicardial contour line as the second contour line for representing the second ROI of the myocardial contour. In addition, one or more segment lines may be included between the endocardial contour line and the epicardial contour line. Preferably, the one or more segment lines are perpendicular or nearly perpendicular to the endocardial contour line.

[0047] Exemplarily, determining a first region of interest (ROI) representing the myocardial contour based on a first key frame and determining a second ROI representing the myocardial contour based on a second key frame includes: automatically determining a plurality of first contour points in the first key frame and automatically determining a plurality of second contour points in the second key frame; automatically determining a first automatic contour line in the first key frame based on the plurality of first contour points and automatically determining a second automatic contour line in the second key frame based on the plurality of second contour points; in response to a user's adjustment operation on the first automatic contour line, obtaining a first contour line in the first key frame, and determining the first ROI representing the myocardial contour based on the first contour line; in response to a user's adjustment operation on the second automatic contour line, obtaining a second contour line in the second key frame, and determining the second ROI representing the myocardial contour based on the second contour line.

[0048] In one embodiment, in the first key frame (e.g., end-diastolic key frame), a plurality of first contour points are automatically generated. The first contour points include endocardial contour points and epicardial contour points. Based on the automatically generated endocardial contour points and epicardial contour points, an endocardial contour line and an epicardial contour line are automatically generated as the first automatic contour lines. Then, the user manually adjusts the first automatic contour lines to obtain the adjusted first contour lines, which are used to characterize the first region of interest of the myocardial contour. In the second key frame (e.g., end-systolic key frame), a plurality of second contour points are automatically generated. The second contour points include endocardial contour points and epicardial contour points. Based on the automatically generated endocardial contour points and epicardial contour points, an endocardial contour line and an epicardial contour line are automatically generated as the second automatic contour lines. Then, the user manually adjusts the second automatic contour lines to obtain the adjusted second contour lines, which are used to characterize the second region of interest of the myocardial contour. In addition, one or more segment lines may be included between the endocardial contour line and the epicardial contour line. Preferably, the one or more segment lines are perpendicular or nearly perpendicular to the endocardial contour line.

[0049] In one embodiment, as Figure 2 shown, the region of interest (ROI) may include Figure 2 the whole of the horseshoe-shaped myocardium shown in

[0050] or one or more segments of the horseshoe-shaped myocardium divided, or the region of interest may include a region of any shape (e.g., circular, square, etc.) of the myocardium. The present application does not limit this.

[0051] The first region of interest and the second region of interest obtained by this method have different shapes, respectively adapted to the myocardial contours at the end-diastolic and end-systolic phases, improving the adaptability of the region of interest to the myocardial contour, conforming to the torsional movement law of the myocardium, and avoiding the situation where the shape of the region of interest remains unchanged during the cardiac cycle.

[0052] Exemplarily, obtaining at least one third region of interest for characterizing a myocardial contour in at least one intermediate frame between a first key frame and a second key frame based on a first region of interest and a second region of interest includes: determining at least one intermediate frame between the first key frame and the second key frame; performing interpolation on the first region of interest of the first key frame and the second region of interest of the second key frame to obtain at least one third region of interest for characterizing the myocardial contour in at least one intermediate frame.

[0053] Exemplarily, obtaining at least one third region of interest for characterizing a myocardial contour in at least one intermediate frame between a first key frame and a second key frame based on a first region of interest and a second region of interest includes: determining at least one intermediate frame between the first key frame and the second key frame; generating a plurality of first control points on the first region of interest of the first key frame and generating a plurality of second control points on the second region of interest of the second key frame, performing interpolation on the plurality of first control points of the first key frame and the plurality of second control points of the second key frame to obtain a plurality of third control points in at least one intermediate frame; automatically determining at least one third automatic contour line in at least one intermediate frame based on the plurality of third control points; determining at least one third region of interest for characterizing the myocardial contour based on the at least one third automatic contour line.

[0054] In one embodiment, as Figure 2 shown, generating a plurality of first control points at equal intervals on the first region of interest of the first key frame, and generating a plurality of second control points at equal intervals on the second region of interest of the second key frame; determining one intermediate frame between the first key frame and the second key frame; based on the position (e.g., phase) of the intermediate frame between the first key frame and the second key frame, performing methods such as linear interpolation on the plurality of first control points and the plurality of second control points to obtain a plurality of third control points in the intermediate frame; the third control points include endocardial control points and epicardial control points, automatically generating an endocardial contour line and an epicardial contour line in the intermediate frame by methods such as spline interpolation based on the plurality of third control points as the third automatic contour line; using the third automatic contour line to characterize the third region of interest of the myocardial contour, or, the user manually adjusts the third automatic contour line to obtain an adjusted third contour line, and using the adjusted third contour line to characterize the third region of interest of the myocardial contour.

[0055] Exemplarily, after obtaining the third region of interest of at least one transitional frame, the following operations may further be performed: in response to an adjustment operation of the user on the third region of interest of any one transitional frame in the target cardiac cycle, determining any one transitional frame as the third key frame; refreshing the third region of interest of at least one transitional frame between the first key frame and the third key frame based on the first region of interest and the third region of interest of the third key frame, and refreshing the third region of interest of at least one transitional frame between the second key frame and the third key frame based on the third region of interest of the third key frame and the second region of interest.

[0056] In one embodiment, after obtaining the above-mentioned third automatic contour line, if the user manually adjusts the third automatic contour line to obtain an adjusted third contour line, then determining this transitional frame as the third key frame; then refreshing the third region of interest of at least one transitional frame between the first key frame and the third key frame based on the first region of interest and the third region of interest of the third key frame, and refreshing the third region of interest of at least one transitional frame between the second key frame and the third key frame based on the third region of interest of the third key frame and the second region of interest, so as to further improve the fitness between the shape of the region of interest of the transitional frame and the myocardial contour and improve the accuracy of myocardial quantitative analysis.

[0057] The third region of interest obtained by this method has a different shape from the above-mentioned first region of interest and second region of interest, avoiding the situation where the shape of the region of interest remains unchanged during the cardiac cycle, improving the fitness between the region of interest and the myocardial contour, and conforming to the torsional movement law of the myocardium.

[0058] In step S350, quantitative parameters of the myocardium changing with time in the region of interest corresponding to the target cardiac cycle are obtained according to the first region of interest, the second region of interest, and at least one third region of interest.

[0059] Exemplarily, when the multi-frame myocardial ultrasound images are multi-frame myocardial ultrasound images of the myocardial contrast reperfusion process, obtaining the quantitative parameters of the myocardium changing with time in the region of interest corresponding to the target cardiac cycle according to the first region of interest, the second region of interest, and at least one third region of interest includes: obtaining a curve of the contrast agent intensity changing with time in the region of interest corresponding to the target cardiac cycle according to the first region of interest, the second region of interest, and at least one third region of interest corresponding to the target cardiac cycle. Further, quantitative analysis is performed on the curve of the contrast agent intensity changing with time in the region of interest to obtain quantitative parameters for evaluating the myocardial perfusion level.

[0060] In one embodiment, the beamforming module 112 performs corresponding delay and weighted summation processing on the reperfusion data or the ultrasonic data corresponding to the ultrasonic echo signal to achieve beamforming, and then sends it to the processor 116. After partial or all of the image post-processing steps such as denoising, smoothing, and enhancement, an ultrasonic image during myocardial reperfusion is obtained. An area of interest is selected from the ultrasonic image, and a time-intensity curve is plotted by quantitative analysis of the area of interest in the ultrasonic image. Using the formula C(t) = A×(1 - e^ (-βt) ), the time intensity is fitted to obtain fitting parameters, where the fitting parameters include one or more of the parameter A for representing blood volume, the parameter β for representing blood flow velocity, and A×β for representing myocardial blood flow.

[0061] Exemplarily, this application is not limited to only obtaining multiple frames of myocardial ultrasonic images of the target cardiac cycle, and may further include: obtaining multiple frames of myocardial ultrasonic images of multiple cardiac cycles; determining the target cardiac cycle among the multiple cardiac cycles, where the target cardiac cycle is one cardiac cycle among the multiple cardiac cycles; determining the first key frame and the second key frame corresponding to the phase of other cardiac cycles according to the phases of the first key frame and the second key frame in the target cardiac cycle, where the other cardiac cycles are at least one of the multiple cardiac cycles except the target cardiac cycle; synchronizing the first area of interest and the second area of interest to the first key frame and the second key frame corresponding to the phases of other cardiac cycles; and obtaining at least one third area of interest for characterizing the myocardial contour in at least one transition frame between the first key frame and the second key frame corresponding to other cardiac cycles based on the first area of interest and the second area of interest corresponding to other cardiac cycles, where at least two of the multiple third areas of interest are different in shape from each other or at least one third area of interest is different in shape from the first area of interest or the second area of interest, where the transition frame is at least one frame other than the first key frame and the second key frame among the multiple frames of myocardial ultrasonic images and one transition frame corresponds to one third area of interest.

[0062] Further, synchronizing the first area of interest and the second area of interest to the first key frame and the second key frame corresponding to the phases of other cardiac cycles includes: synchronizing the first area of interest and the second area of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles except the target cardiac cycle; or synchronizing the first area of interest and the second area of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles before the target cardiac cycle; or synchronizing the first area of interest and the second area of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles after the target cardiac cycle.

[0063] In one embodiment, the heart exhibits periodic motion. Generally, for quantitative analysis of myocardial contrast, cine data for 15 to 20 cardiac cycles need to be stored. After determining the first key frame and the first region of interest, and the second key frame and the second region of interest in the target cardiac cycle, it may further include the step of synchronizing the key frame and its region of interest (ROI) to other cardiac cycles using ECG information. Specifically, according to the ECG phase of the first key frame in the current cardiac cycle, frames with the same or the closest phase are determined as the first key frames of the one or more other cardiac cycles, and the first region of interest is synchronized to the first key frames of the one or more other cardiac cycles; similarly, according to the ECG phase of the second key frame in the current cardiac cycle, frames with the same or the closest phase are determined as the second key frames of the one or more other cardiac cycles, and the second region of interest is synchronized to the second key frames of the one or more other cardiac cycles. For the third key frame and its third region of interest determined in step S340 above, they can also be synchronized to one or more other cardiac cycles in the same manner as the first key frame and its first region of interest. The synchronization process includes but is not limited to the following four modes: no synchronization; synchronization to all cycles; synchronization to the cardiac cycles before the target cardiac cycle; synchronization to the cardiac cycles after the target cardiac cycle. For example, when there is a slight movement of the probe in the contrast data, synchronization to the subsequent cycle can be selected to achieve the effect of quickly editing the key frame. After the synchronization process is completed, at least one third region of interest for characterizing the myocardial contour is obtained from at least one intermediate frame between the first key frame and the second key frame corresponding to the one or more other cardiac cycles based on the first region of interest and the second region of interest corresponding to the one or more other cardiac cycles. The specific process is not described in detail here.

[0064] According to the method for tracking regions of interest in myocardial quantitative analysis provided by the present application, by respectively determining a first region of interest and a second region of interest with different shapes for characterizing the myocardial contour in the first key frame and the second key frame of multiple frames of myocardial ultrasound images in the target cardiac cycle, and further determining a third region of interest with a shape different from the first region of interest and the second region of interest for characterizing the myocardial contour in the intermediate frame based on the first region of interest and the second region of interest, the rapid and flexible adaptation of the region of interest shape to the myocardial contour is achieved, and the accuracy of myocardial quantitative analysis is improved.

[0065] The following refers to Figure 4 Describe the method for tracking regions of interest in myocardial quantitative analysis proposed in the embodiments of the present application. Figure 4It is a schematic flowchart of a method 400 for tracking regions of interest in myocardial quantitative analysis according to an embodiment of the present application. Specifically, the method 400 for tracking regions of interest in myocardial quantitative analysis according to an embodiment of the present application is applied to Figure 1 the ultrasonic imaging system 100 shown in the figure. The ultrasonic imaging system 100 includes an ultrasonic probe 110 and a processor 116. The processor 116 performs the following steps:

[0066] In step S410, multiple frames of myocardial ultrasonic images during the myocardial contrast reperfusion process of multiple cardiac cycles are acquired;

[0067] In step S420, a first key frame and a second key frame are determined from the multiple frames of myocardial ultrasonic images of the target cardiac cycle, where the target cardiac cycle is one of the multiple cardiac cycles;

[0068] In step S430, a first region of interest representing the myocardial contour is determined based on the first key frame, and a second region of interest representing the myocardial contour is determined based on the second key frame, where the shapes of the first region of interest and the second region of interest are different;

[0069] In step S440, the first key frame and the second key frame corresponding to the corresponding phases of other cardiac cycles are determined according to the phases of the first key frame and the second key frame in the target cardiac cycle, where the other cardiac cycles are at least one of the multiple cardiac cycles except the target cardiac cycle;

[0070] In step S450, the first region of interest and the second region of interest are synchronized to the first key frame and the second key frame corresponding to the corresponding phases of the other cardiac cycles;

[0071] In step S460, at least one third region of interest for representing the myocardial contour is obtained from at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or the other cardiac cycles based on the first region of interest and the second region of interest corresponding to the target cardiac cycle and / or the other cardiac cycles. At least two of the multiple third regions of interest are different in shape from each other, or at least one of the third regions of interest is different in shape from the first region of interest or the second region of interest. The transition frame is at least one frame other than the first key frame and the second key frame in the multiple frames of myocardial ultrasonic images of the target cardiac cycle and / or the other cardiac cycles, and one transition frame corresponds to one third region of interest;

[0072] In step S470, a curve of the change of the contrast agent intensity over time in the region of interest corresponding to the target cardiac cycle and / or the other cardiac cycles is obtained based on the first region of interest, the second region of interest, and at least one of the third regions of interest corresponding to the target cardiac cycle and / or the other cardiac cycles.

[0073] After determining the key frames of a cardiac cycle in the cine file, the region of interest tracking method 400 for myocardial quantitative analysis according to the embodiments of the present application can further determine the regions of interest ROI representing the myocardial contours of the transition frames between the key frames based on the regions of interest ROI representing the myocardial contours of the key frames, and synchronize the key frames and the regions of interest ROI to other cardiac cycles of the cine file. In this way, when performing myocardial quantitative analysis, the adaptation of the ROI shape to the myocardial contour can be achieved more quickly and flexibly, improving the accuracy of myocardial quantitative analysis.

[0074] In step S410, multiple frames of myocardial ultrasound images of the myocardial contrast reperfusion process of multiple cardiac cycles are obtained. Myocardial perfusion refers to injecting a contrast agent into the body of a target object. After the contrast agent reaches the heart, ultrasonic imaging is performed on the heart, and the blood supply state of the myocardium is judged according to the results of the ultrasonic imaging. The contrast agent is a solution containing contrast microbubbles and has high echogenicity, that is, the ability to reflect ultrasonic waves. There is a large difference in the echogenicity between the gas in the contrast microbubbles and the human tissue. Therefore, the part containing the contrast microbubbles can produce ultrasonic images with high contrast due to the high echogenicity difference. When the contrast agent is injected intravenously, the contrast agent perfuses into each tissue and organ with the blood flow, enhancing the tissue imaging. The myocardial perfusion process is the process of the contrast agent perfusing into the myocardium, and the myocardial reperfusion process is to use a high mechanical index pulse (High MI Flash) to destroy the contrast microbubbles in the myocardium at a certain moment during the myocardial perfusion process and continuously observe the filling - disappearance process of the contrast agent after that moment. The intensity of the high mechanical index pulse for destroying the contrast microbubbles should be just enough to destroy the contrast microbubbles in the myocardium without destroying the contrast microbubbles in the heart cavity. Generally, the mechanical index can be set between 0.8 and 1.2.

[0075] In step S420, a first key frame and a second key frame are determined in multiple frames of myocardial ultrasound images of the target cardiac cycle, where the target cardiac cycle is one of the multiple cardiac cycles. Exemplarily, the end - diastolic frame is determined in multiple frames of myocardial ultrasound images of the target cardiac cycle, and the end - diastolic frame is used as the first key frame; the end - systolic frame is determined in multiple frames of myocardial ultrasound images of the target cardiac cycle, and the end - systolic frame is used as the second key frame.

[0076] In step S430, a first region of interest (ROI) representing the myocardial contour is determined based on the first key frame, and a second ROI representing the myocardial contour is determined based on the second key frame, where the shapes of the first ROI and the second ROI are different.

[0077] Exemplarily, determining a first ROI representing the myocardial contour based on the first key frame and determining a second ROI representing the myocardial contour based on the second key frame includes: in response to a tracing operation by the user, obtaining a first contour line in the first key frame, and determining the first ROI representing the myocardial contour based on the first contour line; in response to a tracing operation by the user, obtaining a second contour line in the second key frame, and determining the second ROI representing the myocardial contour based on the second contour line.

[0078] Exemplarily, determining a first ROI representing the myocardial contour based on the first key frame and determining a second ROI representing the myocardial contour based on the second key frame includes: automatically determining a plurality of first contour points in the first key frame and automatically determining a plurality of second contour points in the second key frame; in response to a tracing operation by the user on the plurality of first contour points, obtaining a first contour line in the first key frame, and determining the first ROI representing the myocardial contour based on the first contour line; in response to a tracing operation by the user on the plurality of second contour points, obtaining a second contour line in the second key frame, and determining the second ROI representing the myocardial contour based on the second contour line.

[0079] Exemplarily, determining a first ROI representing the myocardial contour based on the first key frame and determining a second ROI representing the myocardial contour based on the second key frame includes: automatically determining a plurality of first contour points in the first key frame and automatically determining a plurality of second contour points in the second key frame; automatically determining a first automatic contour line in the first key frame based on the plurality of first contour points and automatically determining a second automatic contour line in the second key frame based on the plurality of second contour points; in response to an adjustment operation by the user on the first automatic contour line, obtaining a first contour line in the first key frame, and determining the first ROI representing the myocardial contour based on the first contour line; in response to an adjustment operation by the user on the second automatic contour line, obtaining a second contour line in the second key frame, and determining the second ROI representing the myocardial contour based on the second contour line.

[0080] The first ROI and the second ROI obtained by this method have different shapes, are respectively adapted to the myocardial contours at the end-diastolic and end-systolic phases, improve the adaptability of the ROI to the myocardial contour, conform to the torsional movement law of the myocardium, and avoid the situation where the shape of the ROI remains unchanged during the cardiac cycle.

[0081] In steps S440 and S450, the first key frame and the second key frame corresponding to the phases of other cardiac cycles are determined according to the phases of the first key frame and the second key frame in the target cardiac cycle, where the other cardiac cycles are at least one of the multiple cardiac cycles except the target cardiac cycle; the first region of interest and the second region of interest are synchronized to the first key frame and the second key frame corresponding to the phases of the other cardiac cycles.

[0082] Exemplarily, synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of other cardiac cycles includes: synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles except the target cardiac cycle; or, synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles before the target cardiac cycle; or, synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles after the target cardiac cycle.

[0083] In step S460, at least one third region of interest for characterizing the myocardial contour is obtained from at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or other cardiac cycles based on the first region of interest and the second region of interest corresponding to the target cardiac cycle and / or other cardiac cycles, where at least two of the multiple third regions of interest are different in shape from each other or at least one third region of interest is different in shape from the first region of interest or the second region of interest, and where the transition frame is at least one frame other than the first key frame and the second key frame in the multiple myocardial ultrasound images of the target cardiac cycle and / or other cardiac cycles, and one transition frame corresponds to one third region of interest.

[0084] Exemplarily, obtaining at least one third region of interest for characterizing the myocardial contour from at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or other cardiac cycles based on the first region of interest and the second region of interest corresponding to the target cardiac cycle and / or other cardiac cycles includes: determining at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or other cardiac cycles; performing interpolation on the first region of interest of the first key frame and the second region of interest of the second key frame to obtain at least one third region of interest for characterizing the myocardial contour in at least one transition frame.

[0085] In step S470, a curve of the change in the contrast agent intensity over time within the region of interest corresponding to the target cardiac cycle and / or other cardiac cycles is obtained based on the first region of interest, the second region of interest, and at least one third region of interest corresponding to the target cardiac cycle and / or other cardiac cycles. Further, after obtaining the curve of the change in the contrast agent intensity over time within the region of interest corresponding to the target cardiac cycle and / or other cardiac cycles based on the first region of interest, the second region of interest, and at least one third region of interest corresponding to the target cardiac cycle and / or other cardiac cycles, it further includes: performing quantitative analysis on the curve of the change in the contrast agent intensity over time within the region of interest to obtain a quantitative parameter for evaluating the myocardial perfusion level.

[0086] The embodiments of the present application further provide an ultrasonic imaging system for implementing the region of interest tracking method 300 for myocardial quantitative analysis and the region of interest tracking method 400 for myocardial quantitative analysis described above. The ultrasonic imaging system includes an ultrasonic probe, a transmitting circuit, a receiving circuit, a processor, and a display. Referring back again Figure 1 , the ultrasonic imaging system can be implemented as the ultrasonic imaging system 100 shown in Figure 1 . The ultrasonic imaging system 100 may include an ultrasonic probe 110, a transmitting circuit 112, a receiving circuit 114, a processor 116, and a display 118. Optionally, the ultrasonic imaging system 100 may further include a transmit / receive selection switch 120, a beam synthesis module 122, and a memory 124. The transmitting circuit 112 and the receiving circuit 114 may be connected to the ultrasonic probe 110 through the transmit / receive selection switch 120. Descriptions of the relevant components can refer to the relevant descriptions above and will not be elaborated here.

[0087] Among them, the transmitting circuit 112 is used to control the ultrasonic probe 110 to emit ultrasonic waves to the myocardium; the receiving circuit 114 is used to control the ultrasonic probe 110 to receive the echo of the returned ultrasonic waves to obtain an ultrasonic echo signal; the processor 116 is used to perform ultrasonic imaging based on the ultrasonic echo signal; the processor 116 is further used to execute the steps of the region of interest tracking method for myocardial quantitative analysis described above.

[0088] Only the main functions of the components of the ultrasonic imaging system are described above. For more details, refer to the relevant descriptions of the reperfusion data acquisition method for myocardial contrast quantitative analysis and will not be elaborated here.

[0089] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

[0090] Those of ordinary skill in the art will realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0091] In several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0092] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of this application can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0093] Similarly, it should be understood that, in order to streamline this application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of this application, the various features of this application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of this application should not be construed as reflecting the intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected by the corresponding claims, the inventive point lies in that the corresponding technical problems can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of this application.

[0094] Those skilled in the art can understand that, except for features that are mutually exclusive, any combination can be used to combine all the features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all the processes or units of any method or device so disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that provides the same, equivalent, or similar purpose.

[0095] In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments is within the scope of this application and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0096] Each component embodiment of this application can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some of the modules in the article analysis device according to the embodiments of this application. This application can also be implemented as a device program (such as a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing this application can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0097] It should be noted that the above embodiments illustrate rather than limit this application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. This application can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices can be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0098] As described above, it is only the specific implementation manner or the description of the specific implementation manner of this application, and the protection scope of this application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application, and all of them should be covered by the protection scope of this application. The protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. A method for tracking regions of interest in myocardial quantitative analysis, characterized in that, comprising: Obtaining multiple frames of myocardial ultrasound images of a target cardiac cycle; Determining a first key frame and a second key frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle; Determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame, wherein the shapes of the first region of interest and the second region of interest are different; Obtaining at least one third region of interest representing the myocardial contour in at least one transition frame between the first key frame and the second key frame based on the first region of interest and the second region of interest, wherein at least two of the multiple third regions of interest are different in shape from each other or at least one of the third regions of interest is different in shape from the first region of interest or the second region of interest, wherein the transition frame is at least one frame other than the first key frame and the second key frame in the multiple frames of myocardial ultrasound images and one transition frame corresponds to one third region of interest; Obtaining quantitative parameters of the change of the myocardium over time in the region of interest corresponding to the target cardiac cycle according to the first region of interest, the second region of interest and at least one of the third regions of interest.

2. The method according to claim 1, characterized in that, Determining a first key frame and a second key frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle comprises: Determining an end-diastolic frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle, and using the end-diastolic frame as the first key frame; Determining an end-systolic frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle, and using the end-systolic frame as the second key frame.

3. The method according to claim 1, characterized in that, Determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame comprises: In response to a tracing operation by the user, obtaining a first contour line in the first key frame, and determining a first region of interest representing the myocardial contour based on the first contour line; In response to a tracing operation by the user, obtaining a second contour line in the second key frame, and determining a second region of interest representing the myocardial contour based on the second contour line.

4. The method according to claim 1, characterized in that, Determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame comprises: Automatically determining multiple first contour points in the first key frame, and automatically determining multiple second contour points in the second key frame; In response to a tracing operation by the user on the multiple first contour points, obtaining a first contour line in the first key frame, and determining a first region of interest representing the myocardial contour based on the first contour line; In response to a tracing operation by the user on the multiple second contour points, obtaining a second contour line in the second key frame, and determining a second region of interest representing the myocardial contour based on the second contour line.

5. The method according to claim 1, wherein, determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame includes: automatically determining a plurality of first contour points in the first key frame, and automatically determining a plurality of second contour points in the second key frame; automatically determining a first automatic contour line in the first key frame based on the plurality of first contour points, and automatically determining a second automatic contour line in the second key frame based on the plurality of second contour points; in response to a user's adjustment operation on the first automatic contour line, obtaining a first contour line in the first key frame, and determining a first region of interest representing the myocardial contour based on the first contour line; in response to a user's adjustment operation on the second automatic contour line, obtaining a second contour line in the second key frame, and determining a second region of interest representing the myocardial contour based on the second contour line.

6. The method according to any one of claims 3-5, wherein, both the first contour line and the second contour line include an endocardial contour line and an epicardial contour line, and there is at least one segment line between the endocardial contour line and the epicardial contour line.

7. The method according to claim 1, wherein, obtaining at least one third region of interest for representing the myocardial contour in at least one transition frame between the first key frame and the second key frame based on the first region of interest and the second region of interest includes: determining at least one of the transition frames between the first key frame and the second key frame; performing interpolation on the first region of interest of the first key frame and the second region of interest of the second key frame to obtain at least one of the third regions of interest for representing the myocardial contour in at least one of the transition frames.

8. The method according to claim 7, wherein, performing interpolation on the first region of interest of the first key frame and the second region of interest of the second key frame to obtain at least one of the third regions of interest for representing the myocardial contour in at least one of the transition frames includes: generating a plurality of first control points at equal intervals on the first region of interest of the first key frame, and generating a plurality of second control points at equal intervals on the second region of interest of the second key frame; obtaining a plurality of third control points on at least one of the transition frames through linear interpolation according to the plurality of first control points and the plurality of second control points; generating at least one of the third regions of interest for representing the myocardial contour through spline interpolation according to the plurality of third control points on at least one of the transition frames.

9. The method according to claim 1, wherein, further includes: in response to a user's adjustment operation on the third region of interest of any one of the transition frames in the target cardiac cycle, determining any one of the transition frames as a third key frame; Refresh the third region of interest of at least one transitional frame between the first key frame and the third key frame based on the third region of interest of the first region of interest and the third key frame, and refresh the third region of interest of at least one transitional frame between the second key frame and the third key frame based on the third region of interest of the third key frame and the second region of interest.

10. The method according to claim 1, wherein, further comprising: Obtain multiple frames of myocardial ultrasound images of multiple cardiac cycles; Determine the target cardiac cycle among the multiple cardiac cycles, where the target cardiac cycle is one cardiac cycle among the multiple cardiac cycles; Determine the first key frame and the second key frame corresponding to the phases of other cardiac cycles according to the phases of the first key frame and the second key frame in the target cardiac cycle, where the other cardiac cycles are at least one of the multiple cardiac cycles other than the target cardiac cycle; Synchronize the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of the other cardiac cycles; Obtain at least one third region of interest for characterizing the myocardial contour in at least one transitional frame between the first key frame and the second key frame corresponding to the other cardiac cycles based on the first region of interest and the second region of interest corresponding to the other cardiac cycles, where at least two of the multiple third regions of interest are different in shape from each other or at least one of the third regions of interest is different in shape from the first region of interest or the second region of interest, where the transitional frame is at least one frame other than the first key frame and the second key frame in the multiple frames of myocardial ultrasound images and one transitional frame corresponds to one third region of interest.

11. The method according to claim 10, wherein, Synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of the other cardiac cycles includes: Synchronize the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles except the target cardiac cycle; or, Synchronize the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles before the target cardiac cycle; or, Synchronize the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of all other cardiac cycles after the target cardiac cycle.

12. The method according to claim 1, wherein, Obtaining multiple frames of myocardial ultrasound images of the target cardiac cycle includes: obtaining multiple frames of myocardial ultrasound images of the myocardial contrast reperfusion process of the target cardiac cycle; Obtaining the quantitative parameters of the change of myocardial tissue over time in the region of interest corresponding to the target cardiac cycle based on the first region of interest, the second region of interest, and at least one of the third regions of interest includes: obtaining a curve of the change of the contrast agent intensity over time in the region of interest corresponding to the target cardiac cycle based on the first region of interest, the second region of interest, and the at least one third region of interest corresponding to the target cardiac cycle.

13. The method according to claim 12, wherein, further comprising: performing quantitative analysis on the curve of the change of the contrast agent intensity over time in the region of interest to obtain quantitative parameters for evaluating the myocardial perfusion level.

14. A method for tracking a region of interest in myocardial quantitative analysis, wherein, comprising: acquiring multiple frames of myocardial ultrasound images of the myocardial contrast reperfusion process of multiple cardiac cycles; determining a first key frame and a second key frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle, wherein the target cardiac cycle is one of the multiple cardiac cycles; determining a first region of interest representing the myocardial contour based on the first key frame, and determining a second region of interest representing the myocardial contour based on the second key frame, wherein the shapes of the first region of interest and the second region of interest are different; determining the first key frame and the second key frame corresponding to the phases of other cardiac cycles based on the phases of the first key frame and the second key frame in the target cardiac cycle, wherein the other cardiac cycles are at least one of the multiple cardiac cycles other than the target cardiac cycle; synchronizing the first region of interest and the second region of interest to the first key frame and the second key frame corresponding to the phases of the other cardiac cycles; obtaining at least one third region of interest for representing the myocardial contour in at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or the other cardiac cycles based on the first region of interest and the second region of interest corresponding to the target cardiac cycle and / or the other cardiac cycles, wherein at least two of the multiple third regions of interest are different in shape from each other or at least one of the third regions of interest is different in shape from the first region of interest or the second region of interest, wherein the transition frame is at least one frame other than the first key frame and the second key frame in the multiple frames of myocardial ultrasound images of the target cardiac cycle and / or the other cardiac cycles, and one transition frame corresponds to one third region of interest; obtaining a curve of the change of the contrast agent intensity over time in the region of interest corresponding to the target cardiac cycle and / or the other cardiac cycles based on the first region of interest, the second region of interest, and at least one of the third regions of interest corresponding to the target cardiac cycle and / or the other cardiac cycles.

15. The method according to claim 14, wherein, Determining a first region of interest (ROI) representing the myocardial contour based on the first key frame, and determining a second ROI representing the myocardial contour based on the second key frame includes: In response to a user's tracing operation, obtaining a first contour line in the first key frame, and determining a first ROI representing the myocardial contour based on the first contour line; In response to a user's tracing operation, obtaining a second contour line in the second key frame, and determining a second ROI representing the myocardial contour based on the second contour line.

16. The method according to claim 14, wherein, Determining a first ROI representing the myocardial contour based on the first key frame, and determining a second ROI representing the myocardial contour based on the second key frame includes: Automatically determining a plurality of first contour points in the first key frame, and automatically determining a plurality of second contour points in the second key frame; In response to a user's tracing operation on the plurality of first contour points, obtaining a first contour line in the first key frame, and determining a first ROI representing the myocardial contour based on the first contour line; In response to a user's tracing operation on the plurality of second contour points, obtaining a second contour line in the second key frame, and determining a second ROI representing the myocardial contour based on the second contour line.

17. The method according to claim 14, wherein, Determining a first ROI representing the myocardial contour based on the first key frame, and determining a second ROI representing the myocardial contour based on the second key frame includes: Automatically determining a plurality of first contour points in the first key frame, and automatically determining a plurality of second contour points in the second key frame; Automatically determining a first automatic contour line in the first key frame based on the plurality of first contour points, and automatically determining a second automatic contour line in the second key frame based on the plurality of second contour points; In response to a user's adjustment operation on the first automatic contour line, obtaining a first contour line in the first key frame, and determining a first ROI representing the myocardial contour based on the first contour line; In response to a user's adjustment operation on the second automatic contour line, obtaining a second contour line in the second key frame, and determining a second ROI representing the myocardial contour based on the second contour line.

18. The method according to claim 14, wherein, Obtaining at least one third ROI for representing the myocardial contour in at least one transition frame between the first key frame and the second key frame corresponding to the target cardiac cycle and / or the other cardiac cycle based on the first ROI and the second ROI corresponding to the target cardiac cycle and / or the other cardiac cycle includes: Determining at least one of the transition frames between the first key frame and the second key frame corresponding to the target cardiac cycle and / or the other cardiac cycle; Performing interpolation on the first ROI of the first key frame and the second ROI of the second key frame to obtain at least one of the third ROIs for representing the myocardial contour in at least one of the transition frames.

19. The method according to claim 18, wherein, performing interpolation on the first region of interest of the first key frame and the second region of interest of the second key frame to obtain at least one third region of interest for characterizing the myocardial contour in at least one of the transition frames includes: generating a plurality of first control points at equal intervals on the first region of interest of the first key frame, and generating a plurality of second control points at equal intervals on the second region of interest of the second key frame; obtaining a plurality of third control points on at least one of the transition frames through linear interpolation according to the plurality of first control points and the plurality of second control points; generating at least one third region of interest for characterizing the myocardial contour through spline interpolation according to the plurality of third control points on at least one of the transition frames.

20. The method according to claim 14, wherein, after obtaining the curve of the change of the contrast agent intensity over time in the region of interest corresponding to the target cardiac cycle and / or the other cardiac cycle according to the first region of interest, the second region of interest and at least one of the third regions of interest corresponding to the target cardiac cycle and / or the other cardiac cycle, further includes: performing quantitative analysis on the curve of the change of the contrast agent intensity over time in the region of interest to obtain a quantitative parameter for evaluating the myocardial perfusion level.

21. An ultrasonic imaging system, wherein, comprising: an ultrasonic probe; a transmitting / receiving circuit for exciting the ultrasonic probe to emit ultrasonic waves to the myocardium and controlling the ultrasonic probe to receive the echo of the ultrasonic waves to obtain the echo signal of the ultrasonic waves; a processor for performing the steps of the method for tracking the region of interest in myocardial quantitative analysis according to any one of claims 1-20.

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