Blood flow imaging method and ultrasonic imaging device

Abstract

Provided is a blood flow imaging method and an ultrasonic imaging device, the method comprising: transmitting a first ultrasonic wave and a second ultrasonic wave to the vascular tissue of a measured object; receiving a first ultrasonic echo and a second ultrasonic echo to obtain a first and a second ultrasonic echo signal; processing the first ultrasonic echo signal to obtain a vector velocity of blood flow, and obtaining WSS within a first time period based on the vector velocity; obtaining an ultrasonic image of vascular tissue based on the first or second ultrasonic echo signal, and obtaining PWV within the first time period based on the second ultrasonic echo signal; superimposing and displaying the vector velocity on the ultrasonic image, dynamically displaying the blood flow morphology, and simultaneously displaying WSS and PWV. The WSS and PWV of the present invention are measured in the same time period and displayed simultaneously on the ultrasonic image, which improves the accuracy of the analysis, and the combination with the blood flow morphology makes the display more intuitive and has a better visualization effect.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic imaging, and more particularly to a blood flow imaging method and an ultrasonic imaging device. Background Art

[0002] Vascular wall shear stress (WSS) is a hemodynamic parameter, and pulse wave velocity (PWV) is a vascular elasticity parameter. The measured values ​​of both can provide corresponding clues for the occurrence of vascular lesions, so they are both important clinical parameters for evaluating vascular and blood flow status.

[0003] However, although WSS and PWV can be measured separately at present, there is no related product that can measure WSS and PWV simultaneously and synchronously and display the changes of the two over time in combination with the blood flow morphology. When using conventional methods to measure separately, the values ​​of these two parameters are not measured in the same cardiac cycle. If the user wants to combine the two parameters for clinical research and analysis, it will affect the accuracy of the clinical analysis. In addition, the two parameters need to be measured twice, which also brings corresponding inconvenience to the measurement operation. Furthermore, conventional methods cannot display the blood flow morphology while obtaining WSS and PWV values. The intuitive blood flow morphology display can directly allow doctors to make more accurate judgments visually and achieve more stable qualitative analysis. Summary of the invention

[0004] The present invention is proposed to solve the above problems. According to one aspect of the present invention, a blood flow imaging method is provided, the method comprising: transmitting a first ultrasonic wave and a second ultrasonic wave to the vascular tissue of the object to be measured; receiving a first ultrasonic echo of the first ultrasonic wave and a second ultrasonic echo of the second ultrasonic wave to obtain a first ultrasonic echo signal and a second ultrasonic echo signal; processing the first ultrasonic echo signal to obtain a vector velocity of the blood flow, and obtaining a vascular wall shear stress in a first time period based on the vector velocity, wherein the vector velocity of the blood flow includes a velocity magnitude and a velocity direction of the blood flow; obtaining an ultrasonic image of the vascular tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal, and obtaining a pulse wave conduction velocity in the first time period based on the second ultrasonic echo signal; displaying the vector velocity superimposed on the ultrasonic image, and simultaneously displaying the vascular wall shear stress and the pulse wave conduction velocity.

[0005] According to another aspect of the present invention, a blood flow imaging method is provided, the method comprising: transmitting a first ultrasonic wave and a second ultrasonic wave to the vascular tissue of a measured object; receiving a first ultrasonic echo of the first ultrasonic wave and a second ultrasonic echo of the second ultrasonic wave to obtain a first ultrasonic echo signal and a second ultrasonic echo signal; processing the first ultrasonic echo signal to obtain a blood flow velocity, and obtaining a vascular wall shear stress within a first time period based on the blood flow velocity, wherein the blood flow velocity includes a magnitude and a direction of the blood flow velocity; obtaining an ultrasonic image of the vascular tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal, and obtaining a pulse wave conduction velocity within the first time period based on the second ultrasonic echo signal; and simultaneously displaying the vascular wall shear stress and the pulse wave conduction velocity.

[0006] According to another aspect of the present invention, a blood flow imaging method is provided, the method comprising: transmitting an ultrasonic wave to the vascular tissue of a subject to be measured; receiving an ultrasonic echo of the ultrasonic wave to obtain an ultrasonic echo signal; processing the ultrasonic echo signal to obtain a blood flow velocity, and obtaining a vascular wall shear stress within a first time period based on the blood flow velocity, wherein the blood flow velocity includes a magnitude and a direction of the blood flow velocity; obtaining an ultrasonic image of the vascular tissue based on the ultrasonic echo signal, and obtaining a pulse wave conduction velocity within the first time period based on the ultrasonic echo signal; and simultaneously displaying the vascular wall shear stress and the pulse wave conduction velocity.

[0007] According to another aspect of the present invention, there is provided an ultrasonic imaging device, comprising: an ultrasonic probe; a transmitting circuit for stimulating the ultrasonic probe to transmit ultrasonic waves to vascular tissue; a receiving circuit for controlling the ultrasonic probe to receive echoes of ultrasonic waves returned from the vascular tissue to obtain echo signals; a human-computer interaction device for obtaining user input and performing visual output; and a processor for executing the blood flow imaging method as described above.

[0008] According to yet another aspect of the present invention, there is provided an ultrasonic imaging device, comprising: a memory for storing a computer program; and a processor for executing the computer program stored in the memory to implement the method described above.

[0009] According to yet another aspect of the present invention, there is provided a computer-readable storage medium, comprising a computer program, wherein when the computer program is executed by a processor, the method as described above can be performed.

[0010] According to the blood flow imaging method and ultrasonic imaging device of the embodiments of the present invention, the two parameters of blood vessel wall shear stress and pulse wave velocity are measured in the same time period, and the two parameters are displayed simultaneously on the ultrasonic image. When the two parameters are combined for clinical research and analysis, the accuracy of the analysis is greatly improved, and two parameters can be measured in one measurement operation. The measurement operation is simple and convenient, and the combination with the blood flow morphology makes the display more intuitive and has a better visualization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other purposes, features and advantages of the present invention will become more apparent by describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0012] Figure 1 A structural block diagram of an ultrasonic imaging device according to an embodiment of the present invention is shown;

[0013] Figure 2 A structural block diagram of an ultrasonic imaging device according to an embodiment of the present invention is shown;

[0014] Figure 3 A schematic diagram showing a vector velocity synthesis method according to an embodiment of the present invention is shown;

[0015] Figure 4 A schematic diagram showing the vector velocity of blood flow and the shear stress of the blood vessel wall according to an embodiment of the present invention is shown;

[0016] Figure 5 A graph showing the change in diameter of a blood vessel wall over time according to an embodiment of the present invention is shown;

[0017] Figure 6 A schematic diagram showing a plurality of measurement points on a blood vessel wall according to an embodiment of the present invention;

[0018] Figure 7 A schematic diagram showing fitting of position information of measurement points on a blood vessel wall that change with time according to an embodiment of the present invention is shown;

[0019] Figure 8 A schematic diagram showing blood vessel wall shear stress and pulse wave velocity according to an embodiment of the present invention is shown;

[0020] Fig. 9 A schematic diagram showing blood vessel wall shear stress and pulse wave velocity according to another embodiment of the present invention is shown;

[0021] Fig.10 A flow chart showing the steps of a blood flow imaging method according to an embodiment of the present invention is shown;

[0022] Fig.11 A flow chart showing the steps of a blood flow imaging method according to another embodiment of the present invention; and

[0023] Fig.12 A flow chart showing the steps of a blood flow imaging method according to yet another embodiment of the present invention is shown. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0025] As mentioned above, due to the existing blood flow imaging methods and ultrasonic imaging equipment, the measured values ​​of the two parameters, vascular wall shear stress and pulse wave velocity, are not measured in the same cardiac cycle, which will affect the accuracy of clinical analysis when combined for analysis, and the measurement operations are carried out separately, which also brings corresponding inconvenience to the measurement operations.

[0026] The blood flow imaging method and ultrasonic imaging device of the present invention can be applied to the human body and various animals, that is, the object to be measured can be a human or various animals.

[0027] The blood flow imaging method and ultrasonic imaging device according to the present invention are described in detail below in conjunction with specific embodiments.

[0028] In one embodiment of the present invention, an ultrasonic imaging device is provided.

[0029] Reference Figure 1 , Figure 1 FIG. 2 shows a block diagram of an ultrasonic imaging device according to an embodiment of the present invention. Figure 1 As shown, the ultrasound imaging device may include an ultrasound probe 30, a transmitting / receiving circuit 40 (i.e., a transmitting circuit 410 and a receiving circuit 420), a beamforming module 50, an IQ demodulation module 60, a processor 20, a human-computer interaction device 70, and a memory 80. Among them:

[0030] The ultrasonic probe 30 may include a transducer (not shown in the figure) composed of a plurality of array elements arranged in an array, wherein the plurality of array elements are arranged in a row to form a linear array, or arranged in a two-dimensional matrix to form a surface array, or the plurality of array elements may also form a convex array. The array element is used to transmit an ultrasonic wave according to an excitation electrical signal, or to convert the received ultrasonic wave into an electrical signal. Therefore, each array element may be used to realize the mutual conversion between an electrical pulse signal and an ultrasonic wave, thereby realizing the transmission of an ultrasonic wave to the object to be imaged 10 (e.g., the vascular tissue in this embodiment), and may also be used to receive the echo of the ultrasonic wave reflected back by the object to be imaged. When performing ultrasonic detection, the transmitting circuit 410 and the receiving circuit 420 may be used to control which array elements are used to transmit an ultrasonic wave and which array elements are used to receive an ultrasonic wave, or control the array elements to transmit an ultrasonic wave or receive an ultrasonic wave echo in a time slot. The array elements participating in the ultrasonic wave transmission may be excited by electrical signals at the same time, thereby transmitting an ultrasonic wave at the same time; or the array elements participating in the ultrasonic wave transmission may also be excited by a plurality of electrical signals with a certain time interval, thereby continuously transmitting an ultrasonic wave with a certain time interval.

[0031] The array element uses, for example, a piezoelectric crystal, and converts the electrical signal into an ultrasonic signal according to the transmission sequence transmitted by the transmitting circuit 410. Depending on the purpose, the ultrasonic signal may include one or more scanning pulses, one or more reference pulses, one or more push pulses and / or one or more Doppler pulses. According to the wave form, the ultrasonic signal includes a focused wave, a plane wave and a diverging wave.

[0032] The user moves the ultrasonic probe 30 to select a suitable position and angle to transmit ultrasonic waves to the object to be imaged 10 and receive the echo of the ultrasonic waves returned by the object to be imaged 10, and outputs an ultrasonic echo signal. The ultrasonic echo signal is a channel analog electrical signal formed by the receiving array element as a channel, which carries amplitude information, frequency information and time information.

[0033] The transmitting circuit 410 is used to generate a transmitting sequence according to the control of the processor 20. The transmitting sequence is used to control some or all of the multiple array elements to transmit ultrasound to the object to be imaged. The transmitting sequence parameters include the array element position, the number of array elements and the ultrasound beam transmission parameters (such as amplitude, frequency, number of transmissions, transmission interval, transmission angle, waveform, focus position, etc.) used for transmission. In some cases, the transmitting circuit 410 is also used to phase delay the transmitted beam so that different transmitting array elements transmit ultrasound at different times so that each transmitted ultrasound beam can be focused on a predetermined area of ​​interest. Different working modes, such as B image mode, C image mode and D image mode (Doppler mode), may have different transmitting sequence parameters. After the echo signal is received by the receiving circuit 420 and processed by subsequent modules and corresponding algorithms, a B image reflecting the anatomical structure of the tissue, a C image reflecting the blood flow information and a D image reflecting the Doppler spectrum image can be generated.

[0034] The receiving circuit 420 is used to receive the ultrasonic echo signal from the ultrasonic probe 30 and process the ultrasonic echo signal. The receiving circuit 420 may include one or more amplifiers, analog-to-digital converters (ADCs), etc. The amplifier is used to amplify the received echo signal after appropriate gain compensation, and the amplifier is used to sample the analog echo signal at a predetermined time interval to convert it into a digitized echo signal, and the digitized echo signal still retains amplitude information, frequency information, and phase information. The data output by the receiving circuit 420 can be output to the beamforming module 50 for processing, or output to the memory 80 for storage.

[0035] The beamforming module 50 is connected to the receiving circuit 420 signal, and is used to perform beamforming processing such as corresponding delay and weighted summation on the echo signal. Since the distances from the ultrasonic receiving point in the measured tissue to the receiving array element are different, the channel data of the same receiving point output by different receiving array elements have delay differences, and delay processing is required to align the phases and perform weighted summation on the different channel data of the same receiving point to obtain the ultrasound image data after beamforming. The ultrasound image data output by the beamforming module 50 is also called radio frequency data (RF data). The beamforming module 50 outputs the radio frequency data to the IQ demodulation module 60. In some embodiments, the beamforming module 50 may also output the radio frequency data to the memory 80 for caching or storage, or directly output the radio frequency data to the processor 20 for image processing.

[0036] The beamforming module 50 may perform the above functions in the form of hardware, firmware or software. For example, the beamforming module 50 may include a central controller circuit (CPU) capable of processing input data according to specific logic instructions, one or more microprocessor chips or any other electronic components. When the beamforming module 50 is implemented in software, it may execute instructions stored in a tangible and non-transitory computer-readable medium (e.g., a memory) to perform beamforming calculations using any appropriate beamforming method. The beamforming module 50 may be integrated in the processor 20 or may be provided separately, which is not limited in the present invention.

[0037] The IQ demodulation module 60 removes the signal carrier through IQ demodulation, extracts the tissue structure information contained in the signal, and performs filtering to remove noise. The signal obtained at this time is called a baseband signal (IQ data pair). The IQ demodulation module 60 outputs the IQ data pair to the processor 20 for image processing.

[0038] In some embodiments, the IQ demodulation module 60 further outputs the IQ data pair to the memory 80 for caching or storage, so that the processor 20 reads the data from the memory 80 for subsequent image processing.

[0039] The IQ demodulation module 60 may also perform the above functions in the form of hardware, firmware or software. In some embodiments, the IQ demodulation module 60 may also be integrated with the beamforming module 50 in one chip.

[0040] The human-computer interaction device 70 is used for human-computer interaction, that is, receiving user input and outputting visual information; it can receive user input using a keyboard, operation buttons, mouse, trackball, etc., or a touch screen integrated with a display; it can output visual information using a display.

[0041] The processor 20 is configured to be a central controller circuit (CPU), one or more microprocessors, a graphics controller circuit (GPU) or any other electronic component that can process input data according to specific logical instructions. It can control peripheral electronic components according to input instructions or predetermined instructions, or read and / or save data from the memory 80. It can also process the input data by executing the program in the memory 80, for example, performing one or more processing operations on the collected ultrasound data according to one or more working modes. The processing operations include but are not limited to adjusting or limiting the form of ultrasound waves emitted by the ultrasound probe 30, generating various image frames for subsequent display of the human-computer interaction device 70, or adjusting or limiting the content and form displayed on the display, or adjusting one or more image display settings displayed on the display (such as ultrasound images, interface components, and positioning areas of interest).

[0042] As echo signals are received, the acquired ultrasound data may be processed by the processor 20 in real time during scanning, or may be temporarily stored on the memory 80 and processed in quasi-real time in either on-line or off-line operation.

[0043] In this embodiment, the processor 20 controls the operation of the transmitting circuit 410 and the receiving circuit 420, for example, controls the transmitting circuit 410 and the receiving circuit 420 to work alternately or simultaneously. The processor 20 can also determine a suitable working mode according to the user's selection or the setting of the program, form a transmission sequence corresponding to the current working mode, and send the transmission sequence to the transmitting circuit 410, so that the transmitting circuit 410 uses the suitable transmission sequence to control the ultrasound probe 30 to transmit ultrasound to the vascular tissue of the object under test.

[0044] The processor 20 is also used to execute the blood flow imaging method of the following embodiment of the present invention.

[0045] In another embodiment of the present invention, an ultrasonic imaging device is provided.

[0046] refer to Figure 2 , Figure 2 FIG. 2 shows a block diagram of an ultrasonic imaging device 200 according to an embodiment of the present invention. Figure 2 As shown, the ultrasonic imaging device 200 includes a memory 220 and a processor 240. The memory 220 is used to store computer programs; the processor 240 is used to execute the computer programs stored in the memory 220, thereby implementing the blood flow imaging method of the following embodiment of the present invention.

[0047] Exemplarily, the memory 220 may be a flash memory 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.

[0048] Exemplarily, the processor 240 may be implemented by software, hardware, firmware, or any combination thereof, and may use circuits, single or multiple application-specific integrated circuits (ASICs), single or multiple general-purpose integrated circuits, single or multiple microprocessors, single or multiple programmable logic devices, or any combination of the foregoing circuits and / or devices, or other suitable circuits or devices, so that the processor 240 can execute the corresponding steps of the methods in the various embodiments of the present specification.

[0049] In yet another embodiment of the present invention, a blood flow imaging method is provided.

[0050] refer to Fig.10 , Fig.10 FIG. 1 is a flow chart showing the steps of a blood flow imaging method 1000 according to an embodiment of the present invention. Fig.10 As shown, the blood flow imaging method 1000 may include the following steps:

[0051] Step S1010: transmitting a first ultrasonic wave and a second ultrasonic wave to the vascular tissue of the object under test.

[0052] Exemplarily, the first ultrasonic wave and the second ultrasonic wave are emitted alternately. Exemplarily, the time interval between two adjacent emissions of the first ultrasonic wave and the second ultrasonic wave may be 10 -4 ~10 -3 s.

[0053] Exemplarily, the first ultrasonic wave includes a focused wave and / or a non-focused wave, and the second ultrasonic wave includes a focused wave and / or a non-focused wave. Exemplarily, the non-focused wave includes a plane wave or a diverging wave.

[0054] Step S1020: receiving a first ultrasonic echo of the first ultrasonic wave and a second ultrasonic echo of the second ultrasonic wave to obtain a first ultrasonic echo signal and a second ultrasonic echo signal.

[0055] The first ultrasonic echo signal and the second ultrasonic echo signal carry amplitude information, frequency information and time information.

[0056] Step S1030: Process the first ultrasonic echo signal to obtain the vector velocity of the blood flow, and obtain the blood vessel wall shear stress WSS in the first time period based on the vector velocity, wherein the vector velocity of the blood flow includes the velocity magnitude and velocity direction of the blood flow.

[0057] Among them, the vector velocity mentioned in this article has a velocity magnitude that is the actual velocity magnitude of the blood flow (such as red blood cells in the blood flow), or is closer to the actual velocity magnitude of the blood flow (such as red blood cells in the blood flow); the velocity direction is the actual flow direction of the blood flow (such as red blood cells in the blood flow), or is closer to the actual flow direction of the blood flow (such as red blood cells in the blood flow); the direction of the vector velocity can be in the range of 0° to 360° in the imaging plane, and its direction can represent the actual flow direction of the blood flow.

[0058] Exemplarily, the vector velocity of blood flow can be calculated using a speckle tracking method, a transverse wave oscillation method, or a multi-angle deflection transmission / reception method based on the Doppler principle.

[0059] Taking the method of obtaining the vector velocity by multi-angle deflection transmission / reception as an example, the first ultrasonic wave includes ultrasonic waves transmitted to the vascular tissue of the object to be measured along at least two scanning angles, and the first ultrasonic echo signal includes ultrasonic echo signals corresponding to the at least two scanning angles. Among them, processing the first ultrasonic echo signal to obtain the vector velocity of the blood flow may include: processing the ultrasonic echo signals corresponding to the at least two scanning angles to obtain at least two velocity components corresponding to the at least two scanning angles; and performing angle synthesis on the at least two velocity components to obtain the vector velocity of the blood flow.

[0060] Specifically, taking two scanning angles as an example, the ultrasonic probe transmits a first ultrasonic wave to the target vascular tissue via a transmitting circuit along a first scanning angle, and receives a first ultrasonic echo of the first ultrasonic wave returned from the target vascular tissue via a receiving circuit through the ultrasonic probe. The processor can obtain a first ultrasonic echo signal along the first scanning angle based on the first ultrasonic echo, and obtain a first blood flow velocity of the target position (also called a target point) on the target vascular tissue according to the first ultrasonic echo signal. The first blood flow velocity is actually a projection component (also called a velocity component) of the vector velocity of the target position at the first scanning angle. Similarly, the ultrasonic probe transmits a first ultrasonic wave to the target vascular tissue via a transmitting circuit along a second scanning angle, and can obtain a second blood flow velocity at the target position. The second blood flow velocity is actually a projection component (also called a velocity component) of the vector velocity of the target position at the second scanning angle. Angle synthesis of the first blood flow velocity and the second blood flow velocity is performed to obtain the actual velocity magnitude and direction, that is, the vector velocity. As Figure 3As shown in FIG. 1 , the velocity component of the vector velocity of the target position at the first scanning angle is the first blood flow velocity v1, and the velocity component of the vector velocity of the target position at the second scanning angle is the second blood flow velocity v2. By angle synthesis, perpendicular lines are drawn for the two velocity components respectively, and the vector velocity of the target position can be determined according to the intersection of the two perpendicular lines. The above angle synthesis of velocity components corresponding to two different scanning angles is only a schematic illustration. For the synthesis of velocity components corresponding to different scanning angles, please refer to Figure 3 This application does not limit the number of scanning angles, that is, the number of velocity components. For the angle synthesis of velocity components corresponding to three or more scanning angles, you can also refer to the above related instructions for understanding, which will not be exhaustive here.

[0061] It should be noted that the velocity components at different scanning angles can be obtained by using the autocorrelation method.

[0062] The calculation formula of the velocity component can be referred to as follows:

[0063]

[0064]

[0065] Among them, v i represents the velocity components calculated at different scanning angles (for example, when there are two different angles, such as Figure 3 As shown in the formula, i = 1, 2, v1 and v2 represent the velocity components at two different scanning angles), f0 represents the center frequency of the probe transmitting signal, and f PRF represents the transmission PRF (Pulse Repetition Frequency) at the same scanning angle, N represents the number of transmissions, x(m) represents the real part of the signal after the mth transmission and reception processing, y(m) represents the imaginary part of the signal after the mth transmission and reception processing, is the imaginary part operator, is the real part operator, and j is the imaginary unit.

[0066] Exemplarily, the vector velocity can also be obtained based on the vector blood flow imaging method of speckle tracking. The vector velocity calculation of speckle tracking can be realized by using the absolute difference sum. The vector velocity with higher accuracy can also be obtained based on the plane wave emission and speckle tracking method.

[0067] For example, the vector velocity can also be obtained by a vector blood flow imaging method based on the transverse wave oscillation method, wherein the longitudinal velocity is obtained by a traditional calculation method based on the Doppler principle, the transverse velocity is calculated based on the autocorrelation method by generating a transverse oscillating ultrasonic sound field, and then the transverse and longitudinal velocities are combined to obtain the vector velocity.

[0068] Exemplarily, the vascular wall shear stress may be calculated from the vector velocity of blood flow using the following formula:

[0069]

[0070] Where τ is the vascular wall shear stress (WSS), μ is the blood viscosity coefficient, r is the radius of the blood vessel, and v represents the velocity component of the blood flow vector velocity in the tangential direction of the vascular wall (see Figure 4 ), and when the blood vessel wall is a straight line, it is the direction parallel to the blood vessel wall.

[0071] Among them, when the blood flow is in a non-laminar state, the shear stress of the blood vessel wall can be obtained by vector blood flow imaging.

[0072] When blood flow is laminar, the shear stress of the vascular wall can be obtained by traditional methods (e.g., pulsed Doppler (PW)). In this case, formula (1) can be simplified to:

[0073]

[0074] Where d is the diameter (inner diameter) of the blood vessel, v max It is the maximum blood flow velocity (spatial maximum) at the center of the blood vessel and can be measured by the pulsed Doppler method.

[0075] Exemplarily, the vascular wall shear stress may include an average value and / or a maximum value, and the average value and / or the maximum value of the vascular wall shear stress in the first time period may be measured respectively.

[0076] Exemplarily, the first time period includes at least one cardiac cycle.

[0077] Step S1040: obtaining an ultrasonic image of the vascular tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal, and obtaining a pulse wave velocity PWV within a first time period based on the second ultrasonic echo signal.

[0078] Exemplarily, the ultrasound image may be an ultrasound grayscale image (B image for short) representing blood vessels or other tissue structures, or a color ultrasound Doppler blood flow image (color ultrasound Color image for short) representing blood flow information. Signal processing methods for ultrasound echo signals include, but are not limited to, beamforming, orthogonal demodulation, wall filtering, color coding, etc. of ultrasound echo signals. The obtained ultrasound image may be stored in a memory, and the ultrasound image may be displayed on a display. Among them, the wall filtering step of conventional color ultrasound processing may use conventional infinite impulse response filters (IIR) or finite impulse response filters (FIR) and other filters to obtain a blood flow signal with a high signal-to-noise ratio, and then process the blood flow signal to calculate the blood flow velocity.

[0079] Exemplarily, the method for obtaining the pulse wave conduction velocity within a first time period based on a second ultrasonic echo signal includes: obtaining an ultrasonic grayscale image of vascular tissue according to the second ultrasonic echo signal, obtaining position information of a vascular wall of the vascular tissue according to the ultrasonic grayscale image, and obtaining the pulse wave conduction velocity within the first time period according to the position information of the vascular wall.

[0080] Exemplarily, the pulse wave velocity may include an early systolic measurement value and / or a late systolic measurement value of the pulse wave velocity, wherein the early systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the early systolic period, and the late systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the late systolic period.

[0081] Exemplarily, a specific method for obtaining the pulse wave velocity according to the ultrasonic grayscale image may include:

[0082] First, the position information of the blood vessel wall at different times is obtained by using ultrasound grayscale imaging, and then the time when the diameter (inner diameter of the blood vessel) reaches the maximum value ( Figure 5 The middle dot position) is taken as the starting point, and a period of time is taken forward as the time period of the early contraction pulse wave propagation. In this time period, the moments when the diameter of several different positions on the blood vessel wall reaches the maximum are extracted to obtain several measurement points corresponding to space and time (see Figure 6 ). Fit these points (see Figure 7 ), and obtain the early systolic measurement value of the pulse wave velocity. Among them, the spatial information of these points is the curvilinear distance between the measurement points on the vascular wall along the direction of the vascular wall. When the vascular wall is a straight vessel, the distance between the measurement points is its horizontal distance.

[0083] Then, the moment when the pipe diameter reaches its maximum value for the second time ( Figure 5 The starting point is the middle triangle position, and a period of time is taken forward as the time period of late systolic pulse wave propagation. In this time period, the moments when the diameter of several different positions on the vascular wall reaches the maximum are extracted to obtain several points corresponding to space and time. These points are fitted to obtain the late systolic measurement value of the pulse wave conduction velocity.

[0084] The above method uses the maximum value of the pipe diameter as the corresponding calculation parameter. In addition, other parameters can also be used as calculation parameters, for example, the maximum value of the pipe diameter change speed (calculated by taking the first-order derivative with respect to time), the maximum value of the pipe diameter change acceleration (calculated by taking the second-order derivative with respect to time), and so on.

[0085] Exemplarily, the first time period includes at least one cardiac cycle.

[0086] Step S1050: superimposing and displaying the vector velocity on the ultrasound image, and simultaneously displaying the vascular wall shear stress and the pulse wave velocity.

[0087] It should be noted that the vascular wall shear stress and the pulse wave velocity can be displayed simultaneously on the ultrasound image at the same time, or can be displayed simultaneously on the ultrasound images at different times. The simultaneous display can be displayed simultaneously in the same ultrasound image window on the same screen, or in different ultrasound image windows on the same screen; or can be displayed simultaneously on different screens, for example, one screen displays the vascular wall shear stress and the other screen displays the pulse wave velocity.

[0088] Exemplarily, the vector velocity is represented on the ultrasound image by a dynamic or static marker, wherein the orientation of the marker represents the velocity direction of the vector velocity, and the size or transparency of the marker represents the velocity magnitude of the vector velocity.

[0089] Exemplarily, the vector velocity is represented by a dynamic marker on an ultrasound image, including: the position of the marker on two adjacent frames of the ultrasound image is dynamically updated to form a flow-like effect that changes over time, wherein the position of the marker represents the corresponding position of the blood flow in the vascular tissue.

[0090] It should be noted that the dynamic display of vector blood flow can be presented by displaying dynamic markers on the ultrasound image. The specific implementation can refer to the description below: first, the magnitude and direction of the vector velocity of the blood flow in the current frame are obtained, and then some markers are randomly displayed in the ultrasound image of the vascular tissue. Among them, these markers can be symbols such as arrows, triangles, circles, etc. According to the magnitude and direction of the vector velocity of the blood flow corresponding to the position of each marker in the current frame, combined with the time interval between two adjacent frames, the position of the marker in the next frame is calculated, and then the marker is displayed. Similarly, when several frames of images are displayed together, the flow effect of blood flow can be visually presented.

[0091] Exemplarily, the method 1000 may further include: simultaneously displaying the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows. The vascular wall shear stress and the pulse wave velocity are obtained based on the ultrasound echo signal processing in the same time period or the same cardiac cycle, and can be simultaneously displayed in real time in different ultrasound image windows, so that the user can observe the state of the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows.

[0092] See also Figure 8, shows a schematic diagram of displaying vascular wall shear stress and pulse wave velocity according to an embodiment, wherein (a) WSSI represents vascular wall shear stress imaging, and the line segment with an arrow represents the vector velocity (wherein, the length of the line segment represents the magnitude of the velocity, and the direction of the arrow represents the direction of the velocity); (b) PWVI represents pulse wave velocity imaging, and the line segment with an arrow represents the vector velocity (wherein, the length of the line segment represents the magnitude of the velocity, and the direction of the arrow represents the direction of the velocity).

[0093] Exemplarily, method 1000 may further include: representing the average value and the maximum value of the vascular wall shear stress with different colors on the ultrasound image. Exemplarily, the different colors may include: different shades of the same color (e.g., dark green, light green, etc.) or different colors (e.g., red, green, etc.).

[0094] Exemplarily, method 1000 may further include: representing the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the ultrasound image with different colors. Exemplarily, the different colors may include: different shades of the same color (e.g., dark blue, light blue, etc.) or different colors (e.g., blue, yellow, etc.).

[0095] Exemplarily, the method 1000 may further include: segmenting a vessel wall of the vascular tissue on the ultrasound image. Exemplarily, the vessel wall may be automatically identified or manually drawn.

[0096] Exemplarily, the method for automatically identifying the blood vessel wall may be: setting respective thresholds for different parts of the blood vessel tissue, and automatically identifying different parts, such as the blood vessel wall, blood flow, tissue, etc., on the ultrasound image according to the respective thresholds, thereby segmenting the blood vessel wall of the blood vessel tissue. For example, a high value is the blood vessel wall, a low value is the blood flow, and a medium value is the tissue.

[0097] Exemplarily, the method for automatically identifying the blood vessel wall may also be: obtaining a blood flow energy image of the blood vessel tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal, setting respective blood flow energy thresholds for different parts of the blood vessel tissue, and automatically identifying different parts, such as the blood vessel wall, blood flow, tissue, etc., on the blood flow energy image according to the respective blood flow energy thresholds, thereby segmenting the blood vessel wall of the blood vessel tissue. For example, high blood flow energy is blood flow, and low blood flow energy is blood vessel wall or tissue.

[0098] Exemplarily, the blood vessel wall may also be manually drawn on the ultrasound image to obtain the blood vessel wall.

[0099] Exemplarily, method 1000 may further include: displaying the average value and the maximum value of the vascular wall shear stress on the inner wall and the outer wall of the vascular wall of the vascular tissue, respectively. Exemplarily, method 1000 may further include: displaying the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the inner wall and the outer wall of the vascular wall of the vascular tissue, respectively.

[0100] Exemplarily, the vascular wall shear stress and pulse wave velocity and the corresponding images may be displayed in a left-right arrangement, or in a top-bottom arrangement, or in other arrangements.

[0101] See also Fig. 9 , shows a schematic diagram of displaying vascular wall shear stress and pulse wave velocity according to another embodiment, wherein (a) WSSI represents vascular wall shear stress imaging, the inner wall of the vascular wall is an imaging of the average value of vascular wall shear stress, the outer wall of the vascular wall is an imaging of the maximum value of vascular wall shear stress, and the line segment with an arrow represents the vector velocity (wherein the length of the line segment represents the magnitude of the velocity, and the direction of the arrow represents the direction of the velocity); (b) PWVI represents pulse wave velocity imaging, the inner wall of the vascular wall is an imaging of the late contraction measurement value of the pulse wave velocity, the outer wall of the vascular wall is an imaging of the early contraction measurement value of the pulse wave velocity, and the line segment with an arrow represents the vector velocity (wherein the length of the line segment represents the magnitude of the velocity, and the direction of the arrow represents the direction of the velocity).

[0102] In yet another embodiment of the present invention, a blood flow imaging method is provided.

[0103] refer to Fig.11 , Fig.11 FIG. 2 shows a blood flow imaging method 2000 according to an embodiment of the present invention. Fig.11 As shown, the blood flow imaging method 2000 may include the following steps:

[0104] Step S2010: transmitting a first ultrasonic wave and a second ultrasonic wave to the vascular tissue of the object under test.

[0105] Exemplarily, the first ultrasonic wave and the second ultrasonic wave are emitted alternately. Exemplarily, the time interval between two adjacent emissions of the first ultrasonic wave and the second ultrasonic wave may be 10 -4 ~10 -3 s.

[0106] Exemplarily, the first ultrasonic wave includes a focused wave and / or a non-focused wave, and the second ultrasonic wave includes a focused wave and / or a non-focused wave. Exemplarily, the non-focused wave includes a plane wave or a diverging wave.

[0107] Step S2020: receiving a first ultrasonic echo of the first ultrasonic wave and a second ultrasonic echo of the second ultrasonic wave to obtain a first ultrasonic echo signal and a second ultrasonic echo signal.

[0108] The first ultrasonic echo signal and the second ultrasonic echo signal carry amplitude information, frequency information and time information.

[0109] Step S2030: Process the first ultrasonic echo signal to obtain the blood flow velocity, and obtain the blood vessel wall shear stress in the first time period based on the blood flow velocity. The blood flow velocity includes the blood flow velocity magnitude and velocity direction.

[0110] The blood flow velocity includes the blood flow vector velocity or the blood flow velocity along the ultrasonic wave propagation direction based on pulse Doppler. The blood flow vector velocity is calculated by speckle tracking method, transverse wave oscillation method or multi-angle deflection transmission and / or reception method based on Doppler principle. The specific calculation method is as described above and will not be repeated here.

[0111] Exemplarily, the vascular wall shear stress may include an average value and / or a maximum value, and the average value and / or the maximum value of the vascular wall shear stress in the first time period may be measured respectively. The method and formula for calculating the vascular wall shear stress from the blood flow velocity are as described above and will not be repeated here.

[0112] Exemplarily, the first time period includes at least one cardiac cycle.

[0113] Step S2040: obtaining an ultrasonic image of the vascular tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal, and obtaining the pulse wave velocity within the first time period based on the second ultrasonic echo signal.

[0114] Exemplarily, the ultrasound image may be an ultrasound grayscale image (B image for short) representing blood vessels or other tissue structures, or a color ultrasound Doppler blood flow image (Color ultrasound image for short) representing blood flow information. Signal processing methods for ultrasound echo signals include, but are not limited to, beamforming, orthogonal demodulation, wall filtering, color coding, etc. of ultrasound echo signals. The obtained ultrasound image may be stored in a memory, and the ultrasound image may be displayed on a display. Among them, the wall filtering step of conventional color ultrasound processing may use conventional IIR or FIR filters to obtain a blood flow signal with a high signal-to-noise ratio, and then process the blood flow signal to calculate the blood flow velocity.

[0115] Exemplarily, the method for obtaining the pulse wave conduction velocity within a first time period based on a second ultrasonic echo signal includes: obtaining an ultrasonic grayscale image of vascular tissue according to the second ultrasonic echo signal, obtaining position information of a vascular wall of the vascular tissue according to the ultrasonic grayscale image, and processing the position information of the vascular wall to obtain the pulse wave conduction velocity within the first time period.

[0116] Exemplarily, the pulse wave velocity may include an early systolic measurement value and / or a late systolic measurement value of the pulse wave velocity, wherein the early systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the early systolic period, and the late systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the late systolic period.

[0117] The specific method for obtaining the pulse wave velocity based on the ultrasonic grayscale image has been described above and will not be repeated here.

[0118] Exemplarily, the first time period includes at least one cardiac cycle.

[0119] Step S2050: Simultaneously display the blood vessel wall shear stress and pulse wave velocity.

[0120] It should be noted that the vascular wall shear stress and pulse wave velocity can be displayed together with the ultrasound image and / or the blood flow velocity; or they can be displayed simultaneously without being combined with the ultrasound image and / or the blood flow velocity or displayed simultaneously on the corresponding vascular model.

[0121] For example, step S2050 may include: displaying an ultrasound image, superimposing and displaying the blood flow velocity on the ultrasound image, and simultaneously displaying the vascular wall shear stress and the pulse wave velocity. The specific method can be understood by referring to the relevant description of the above step S1050, which will not be repeated here.

[0122] Exemplarily, the velocity of blood flow is indicated on an ultrasound image by a dynamic or static marker, wherein the orientation of the marker indicates the direction of the velocity, and the size or transparency of the marker indicates the magnitude of the velocity.

[0123] Exemplarily, the blood flow velocity is represented by a dynamic marker on an ultrasound image, including: the position of the marker on two adjacent frames of ultrasound images is dynamically updated to form a flow-like effect that changes over time, wherein the position of the marker represents the corresponding position of the blood flow in the vascular tissue.

[0124] Exemplarily, the method 2000 may further include: simultaneously displaying the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows. The vascular wall shear stress and the pulse wave velocity are obtained based on the ultrasound echo signal processing in the same time period or the same cardiac cycle, and can be simultaneously displayed in real time in different ultrasound image windows, so that the user can observe the state of the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows.

[0125] Exemplarily, method 2000 may further include: representing the average value and the maximum value of the vascular wall shear stress with different colors on the ultrasound image. Exemplarily, the different colors may include: different shades of the same color (e.g., dark green, light green, etc.) or different colors (e.g., red, green, etc.).

[0126] Exemplarily, the method 2000 may further include: representing the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the ultrasound image with different colors. Exemplarily, the different colors may include: different shades of the same color (e.g., dark blue, light blue, etc.) or different colors (e.g., blue, yellow, etc.).

[0127] Exemplarily, the method 2000 may further include: segmenting the vessel wall of the vascular tissue on the ultrasound image. Exemplarily, the vessel wall may be automatically identified or manually drawn. The specific automatic identification or drawing method is as described above and will not be described in detail here.

[0128] Exemplarily, method 2000 may further include: displaying the average value and the maximum value of the vascular wall shear stress on the inner wall and the outer wall of the vascular wall of the vascular tissue, respectively. Exemplarily, method 2000 may further include: displaying the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the inner wall and the outer wall of the vascular wall of the vascular tissue, respectively.

[0129] Exemplarily, the vascular wall shear stress and pulse wave velocity and the corresponding images may be displayed in a left-right arrangement, or in a top-bottom arrangement, or in other arrangements.

[0130] In yet another embodiment of the present invention, a blood flow imaging method is provided.

[0131] refer to Fig.12 , Fig.12 FIG. 3 shows a blood flow imaging method 3000 according to an embodiment of the present invention. Fig.12 As shown, the blood flow imaging method 3000 may include the following steps:

[0132] Step S3010: transmitting ultrasonic waves to the vascular tissue of the object under test.

[0133] Exemplarily, the ultrasound wave comprises a focused wave and / or a non-focused wave. Exemplarily, the non-focused wave comprises a plane wave or a diverging wave.

[0134] Step S3020: Receive the ultrasonic echo of the ultrasonic wave to obtain an ultrasonic echo signal.

[0135] The ultrasonic echo signal carries amplitude information, frequency information and time information.

[0136] Step S3030: Process the ultrasonic echo signal to obtain the blood flow velocity, and obtain the blood vessel wall shear stress in the first time period based on the blood flow velocity. The blood flow velocity includes the blood flow velocity magnitude and velocity direction.

[0137] The blood flow velocity includes the blood flow vector velocity or the blood flow velocity along the ultrasonic wave propagation direction based on pulse Doppler. The blood flow vector velocity is calculated by speckle tracking method, transverse wave oscillation method or multi-angle deflection transmission and / or reception method based on Doppler principle. The specific calculation method is as described above and will not be repeated here.

[0138] Exemplarily, the vascular wall shear stress may include an average value and / or a maximum value, and the average value and / or the maximum value of the vascular wall shear stress in the first time period may be measured respectively. The method and formula for calculating the vascular wall shear stress from the blood flow velocity are as described above and will not be repeated here.

[0139] Exemplarily, the first time period includes at least one cardiac cycle.

[0140] Step S3040: obtaining an ultrasonic image of the vascular tissue based on the ultrasonic echo signal, and obtaining the pulse wave velocity within the first time period based on the ultrasonic echo signal.

[0141] Exemplarily, the ultrasound image may be an ultrasound grayscale image (B image for short) representing blood vessels or other tissue structures, or a color ultrasound Doppler blood flow image (Color image for short) representing blood flow information.

[0142] Exemplarily, the method for obtaining the pulse wave conduction velocity within a first time period based on an ultrasonic echo signal includes: obtaining an ultrasonic grayscale image of vascular tissue according to the ultrasonic echo signal, obtaining position information of a vascular wall of the vascular tissue according to the ultrasonic grayscale image, and processing the position information of the vascular wall to obtain the pulse wave conduction velocity within the first time period.

[0143] Exemplarily, the pulse wave velocity may include an early systolic measurement value and / or a late systolic measurement value of the pulse wave velocity, wherein the early systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the early systolic period, and the late systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the late systolic period.

[0144] The specific method for obtaining the pulse wave velocity based on the ultrasonic grayscale image has been described above and will not be repeated here.

[0145] Step S3050: Simultaneously display the blood vessel wall shear stress and pulse wave velocity.

[0146] It should be noted that the vascular wall shear stress and pulse wave velocity can be displayed together with the ultrasound image and / or the blood flow velocity; or they can be displayed simultaneously without being combined with the ultrasound image and / or the blood flow velocity or displayed simultaneously on the corresponding vascular model.

[0147] For example, step S3050 may include: displaying an ultrasound image, superimposing and displaying the blood flow velocity on the ultrasound image, and simultaneously displaying the vascular wall shear stress and the pulse wave velocity. The specific method can be understood by referring to the relevant description of the above step S1050, which will not be repeated here.

[0148] Exemplarily, the velocity of blood flow is indicated on an ultrasound image by a dynamic or static marker, wherein the orientation of the marker indicates the direction of the velocity, and the size or transparency of the marker indicates the magnitude of the velocity.

[0149] Exemplarily, the blood flow velocity is represented by a dynamic marker on an ultrasound image, including: the position of the marker on two adjacent frames of ultrasound images is dynamically updated to form a flow-like effect that changes over time, wherein the position of the marker represents the corresponding position of the blood flow in the vascular tissue.

[0150] Exemplarily, the method 3000 may further include: simultaneously displaying the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows. The vascular wall shear stress and the pulse wave velocity are obtained based on the ultrasound echo signal processing in the same time period or the same cardiac cycle, and can be simultaneously displayed in real time in different ultrasound image windows, so that the user can observe the state of the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows.

[0151] Exemplarily, method 3000 may further include: representing the average value and the maximum value of the vascular wall shear stress with different colors on the ultrasound image. Exemplarily, the different colors may include: different shades of the same color (e.g., dark green, light green, etc.) or different colors (e.g., red, green, etc.).

[0152] Exemplarily, the method 3000 may further include: representing the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the ultrasound image with different colors. Exemplarily, the different colors may include: different shades of the same color (e.g., dark blue, light blue, etc.) or different colors (e.g., blue, yellow, etc.).

[0153] Exemplarily, the method 3000 may further include: segmenting the vessel wall of the vascular tissue on the ultrasound image. Exemplarily, the vessel wall may be automatically identified or manually drawn. The specific automatic identification or drawing method is as described above and will not be repeated here.

[0154] Exemplarily, the method 3000 may further include: displaying the average value and the maximum value of the vascular wall shear stress on the inner wall and the outer wall of the vascular wall of the vascular tissue, respectively. Exemplarily, the method 3000 may further include: displaying the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the inner wall and the outer wall of the vascular wall of the vascular tissue, respectively.

[0155] Exemplarily, the vascular wall shear stress and pulse wave velocity and the corresponding images may be displayed in a left-right arrangement, or in a top-bottom arrangement, or in other arrangements.

[0156] In another embodiment of the present invention, a computer-readable medium is provided, on which a computer-executable instruction is stored, and when the computer-executable instruction is executed by a processor, the method described in the above embodiment is executed. Any tangible, non-temporary computer-readable medium can be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD-ROMs, DVDs, Blu-ray discs, etc.), flash memory and / or the like. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to form a machine, so that these instructions executed on a computer or other programmable data processing device can generate a device that implements a specified function. These computer-executable instructions can also be stored in a computer-readable memory, which can instruct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory can form a manufactured product, including an implementation device that implements a specified function. The computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device can provide steps for implementing the specified function.

[0157] Beneficial effects of the present invention:

[0158] According to the blood flow imaging method, ultrasonic imaging device and computer-readable medium of the embodiments of the present invention, the two parameters of vascular wall shear stress and pulse wave velocity are measured in the same time period and displayed simultaneously. When the two parameters are combined for clinical research and analysis, the accuracy of the analysis is greatly improved. Two parameters can be measured in one measurement operation. The measurement operation is simple and convenient. The combination with the blood flow morphology makes the display more intuitive and has a better visualization effect.

[0159] 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 invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as required by the appended claims.

[0160] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0161] Similarly, it should be understood that in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0162] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0163] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0164] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0165] The above is only a specific embodiment or description of a specific embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A blood flow imaging method, characterized in that: The method comprises: In the same cardiac cycle, a first ultrasonic wave and a second ultrasonic wave are alternately transmitted to the vascular tissue of the subject, wherein the first ultrasonic wave includes an ultrasonic wave transmitted to the vascular tissue of the subject along at least two scanning angles, and the time interval between two adjacent transmissions of the first ultrasonic wave and the second ultrasonic wave is 10 -4 ~10 -3 s; receiving a first ultrasonic echo of the first ultrasonic wave and a second ultrasonic echo of the second ultrasonic wave, and obtaining a first ultrasonic echo signal and a second ultrasonic echo signal within the same cardiac cycle, wherein the first ultrasonic echo signal includes ultrasonic echo signals corresponding to the at least two scanning angles; Processing the first ultrasonic echo signal to obtain a vector velocity of blood flow, and obtaining the shear stress of the blood vessel wall in the same cardiac cycle based on the vector velocity, wherein the vector velocity of blood flow includes the magnitude and direction of the velocity of blood flow; wherein the processing the first ultrasonic echo signal to obtain the vector velocity of blood flow includes: processing the ultrasonic echo signals corresponding to the at least two scanning angles to obtain at least two velocity components corresponding to the at least two scanning angles, and performing angle synthesis on the at least two velocity components to obtain the vector velocity of blood flow; Obtaining an ultrasonic image of the vascular tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal, and obtaining a pulse wave velocity within the same cardiac cycle based on the second ultrasonic echo signal; The vector velocity is superimposed and displayed on the ultrasound image, and the blood vessel wall shear stress and the pulse wave velocity are displayed simultaneously.

2. The blood flow imaging method according to claim 1, characterized in that: The vector velocity is represented by a dynamic or static marker on the ultrasound image, wherein the orientation of the marker represents the velocity direction of the vector velocity, and the size or transparency of the marker represents the velocity magnitude of the vector velocity.

3. The blood flow imaging method according to claim 2, characterized in that: The vector velocity is represented by a dynamic marker on the ultrasound image, including: the position of the marker on two adjacent frames of the ultrasound image is dynamically updated to form a flow effect that changes with time, wherein the position of the marker represents the corresponding position of the blood flow in the vascular tissue.

4. The blood flow imaging method according to claim 1, characterized in that: The method for obtaining the pulse wave velocity within the same cardiac cycle based on the second ultrasonic echo signal includes: obtaining an ultrasonic grayscale image of the vascular tissue according to the second ultrasonic echo signal; Obtaining position information of a vascular wall of the vascular tissue according to the ultrasonic grayscale image; The pulse wave conduction velocity in the same cardiac cycle is obtained according to the position information of the blood vessel wall.

5. The blood flow imaging method according to claim 1, characterized in that: The vascular wall shear stress includes an average value and / or a maximum value of the vascular wall shear stress.

6. The blood flow imaging method according to claim 5, characterized in that: The method further includes: representing the average value and the maximum value of the blood vessel wall shear stress with different colors on the ultrasound image.

7. The blood flow imaging method according to claim 5 or 6, characterized in that: The method further includes: displaying the average value and the maximum value of the vascular wall shear stress on the inner wall and the outer wall of the vascular wall of the vascular tissue respectively.

8. The blood flow imaging method according to claim 1, characterized in that: The pulse wave velocity comprises an early systolic measurement value and / or a late systolic measurement value of the pulse wave velocity, wherein the early systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the early systolic period, and the late systolic measurement value represents the measurement value of the pulse wave velocity of the vascular wall of the vascular tissue in the late systolic period.

9. The blood flow imaging method according to claim 8, characterized in that: The method further includes representing the early systolic measurement value and the late systolic measurement value of the pulse wave velocity using different colors on the ultrasound image.

10. The blood flow imaging method according to claim 8 or 9, characterized in that: The method further includes: displaying the early systolic measurement value and the late systolic measurement value of the pulse wave velocity on the inner wall and the outer wall of the blood vessel wall of the blood vessel tissue, respectively.

11. The blood flow imaging method according to claim 1, characterized in that: The simultaneously displaying the vascular wall shear stress and the pulse wave velocity comprises: simultaneously displaying the vascular wall shear stress and the pulse wave velocity in different ultrasound image windows.

12. The blood flow imaging method according to claim 1, characterized in that: The method further comprises: setting respective thresholds for different parts of the vascular tissue; The different parts are automatically identified on the ultrasound image according to the respective thresholds, thereby segmenting the vascular wall of the vascular tissue.

13. The blood flow imaging method according to claim 1, characterized in that: The method further comprises: obtaining a blood flow energy image of the vascular tissue based on the first ultrasonic echo signal or the second ultrasonic echo signal; setting respective blood flow energy thresholds for different parts of the vascular tissue; The different parts are automatically identified on the blood flow energy image according to the respective blood flow energy thresholds, thereby segmenting the blood vessel wall of the blood vessel tissue.

14. The blood flow imaging method according to claim 1, characterized in that: The method further includes manually drawing a blood vessel wall on the ultrasound image to obtain the blood vessel wall.

15. The blood flow imaging method according to claim 1, characterized in that: The first ultrasonic wave includes focused waves and / or unfocused waves, and the second ultrasonic wave includes focused waves and / or unfocused waves.

16. An ultrasonic imaging device, characterized in that: include: Ultrasound probe; A transmitting circuit, used for stimulating the ultrasonic probe to transmit ultrasonic waves to the vascular tissue; A receiving circuit, used for controlling the ultrasonic probe to receive the echo of the ultrasonic wave returned from the vascular tissue to obtain an ultrasonic echo signal; A human-computer interaction device for obtaining user input and performing visual output; A processor, configured to execute the blood flow imaging method as described in any one of claims 1-15.

Images