A method for vascular analysis, an ultrasound imaging device, and a medium

Abstract

This disclosure relates to a method, ultrasound imaging device, and medium for vascular analysis. The method enables the ultrasound imaging device to operate in vector blood flow imaging mode and perform a first ultrasound scan on a region of interest of the blood vessel. A first ultrasound echo signal obtained through the first ultrasound scan can be acquired. Hemodynamic parameters of the region of interest can be determined based on the first ultrasound echo signal or a first vector blood flow image generated accordingly in the vector blood flow mode. Structural and biomechanical parameters of the region of interest can be determined. Then, based on the hemodynamic, structural, and biomechanical parameters of the region of interest, and the biomechanical parameters of the blood vessel, pathological attribute parameters of the blood vessel can be determined. This comprehensively covers all stages of vascular disease development and the physiological mechanisms at various tissue levels, thereby enabling robust and accurate assessment of vascular pathological attributes and significantly reducing false negatives or missed detections.

Description

Technical Field

[0001] This disclosure relates to a medical imaging method, a medical imaging system, and a medium; more specifically, it relates to a vascular analysis method based on an ultrasound imaging device, an ultrasound imaging device, and a computer storage medium storing program instructions for vascular analysis processing. Background Technology

[0002] With the global trend of population aging, various cardiovascular and cerebrovascular diseases, such as arteriosclerosis, vascular plaques, coronary heart disease, and stroke, are becoming major killers of life expectancy. Accurate assessment and prediction of various vascular lesions, especially accurate early assessment and prediction, are of significant clinical value for the prevention and treatment of cardiovascular and cerebrovascular diseases. Taking vascular plaques as an example, their stability is of great concern to doctors. Unstable plaques have the risk of rupture or decomposition, which can lead to stroke, causing irreversible damage, and even disability or death.

[0003] Ultrasound is widely accepted as a non-invasive, real-time imaging method. However, ultrasound is typically only used to examine structural changes in blood vessels (B-mode) and / or blood flow patterns (standard flow mode or vector flow mode). The causes of cardiovascular and cerebrovascular diseases are complex, and traditional ultrasound examinations are insufficient for accurate early assessment of vascular lesions. Plaque stability is difficult to accurately determine based on only one or two traditional parameters; angiography is usually required to confirm the precise vascular lesion status. However, angiography is expensive and involves invasive or minimally invasive procedures, causing considerable discomfort to patients. Summary of the Invention

[0004] Therefore, there is a need for a method, ultrasound imaging equipment, and media for vascular analysis that can comprehensively cover all stages of vascular lesion development and the physiological mechanisms of action at all tissue levels, thereby enabling robust and accurate assessment of the lesion properties of blood vessels and significantly reducing missed detections and false positives.

[0005] According to a first aspect of this disclosure, a method for vascular analysis is provided, applied to an ultrasound imaging device having a vector flow imaging mode. The method may include operating the ultrasound imaging device in a vector flow imaging mode and performing a first ultrasound scan on a region of interest of a blood vessel. The method may include acquiring a first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of the blood vessel. The method may include determining hemodynamic parameters of the region of interest based on the first ultrasound echo signal or a first vector flow image generated in the vector flow mode based on the first ultrasound echo signal. The method may include determining structural mechanical parameters of the region of interest and biomechanical parameters of the blood vessels in the region of interest. The method may include determining pathological attribute parameters of the blood vessel based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest.

[0006] According to a second aspect of this disclosure, an ultrasound imaging apparatus for vascular analysis is provided. The ultrasound imaging apparatus may include an ultrasound probe, a transmit and receive control circuitry, and at least one processor. The ultrasound probe may be used to transmit ultrasound waves toward a region of interest of a blood vessel and receive corresponding ultrasound echoes to obtain an ultrasound echo signal. The transmit and receive control circuitry may be used to output transmit and receive sequences to the ultrasound probe to control the ultrasound probe to transmit ultrasound waves and receive ultrasound echoes. The at least one processor may be configured to control the transmission and reception of the ultrasound probe via the transmit and receive control circuitry, such that the ultrasound imaging apparatus operates in an ultrasound imaging mode including a vector blood flow imaging mode; and to perform a method for vascular analysis according to various embodiments of this disclosure. The method may include causing the ultrasound imaging apparatus to operate in a vector blood flow imaging mode and performing a first ultrasound scan on a region of interest of a blood vessel. The method may include acquiring a first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of a blood vessel. The method may include determining hemodynamic parameters of the region of interest based on the first ultrasound echo signal or a first vector blood flow image generated in the vector blood flow mode based on the first ultrasound echo signal. The method may include determining structural mechanical parameters of the region of interest and biomechanical parameters of the blood vessels in the region of interest. The method may include determining the pathological attribute parameters of the blood vessel based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessel in the region of interest.

[0007] According to a third aspect of this disclosure, a non-volatile computer storage medium is provided storing computer-readable instructions that, when executed by at least one processor, implement a method for vascular analysis according to various embodiments of this disclosure. The method may include causing an ultrasound imaging device to operate in a vector blood flow imaging mode and performing a first ultrasound scan on a region of interest of a blood vessel. The method may include acquiring a first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of the blood vessel. The method may include determining hemodynamic parameters of the region of interest based on the first ultrasound echo signal or a first vector blood flow image generated in the vector blood flow mode based on the first ultrasound echo signal. The method may include determining structural mechanical parameters of the region of interest and biomechanical parameters of the blood vessels in the region of interest. The method may include determining pathological attribute parameters of the blood vessel based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest.

[0008] By utilizing the methods, ultrasound imaging devices, and media for vascular analysis according to various embodiments of the present disclosure, it is possible to comprehensively cover all stages of vascular lesion development and the physiological mechanisms of action at various tissue levels, thereby enabling robust and accurate assessment of the lesion attributes of blood vessels and significantly reducing missed detections and false positives. Attached Figure Description

[0009] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0010] Figure 1 A structural diagram of an ultrasound imaging apparatus according to an embodiment of the present disclosure is shown;

[0011] Figure 2(a) illustrates a first vector blood flow image generated by an ultrasound imaging device according to an embodiment of the present disclosure in vector blood flow imaging mode;

[0012] Figure 2(b) illustrates a second ultrasound image generated by the ultrasound imaging apparatus according to an embodiment of the present disclosure in a conventional ultrasound imaging mode;

[0013] Figure 3 A flowchart illustrating Example 1 of a method for performing vascular analysis using an ultrasound imaging device according to an embodiment of the present disclosure;

[0014] Figure 4 A schematic diagram showing hemodynamic parameters of a region of interest for vascular analysis according to an embodiment of the present disclosure;

[0015] Figures 5(a) and 5(b) show schematic diagrams of the structural mechanical parameters of the region of interest for performing vascular analysis according to embodiments of the present disclosure;

[0016] Figure 6 A schematic diagram showing the biomechanical parameters of blood vessels in the region of interest for performing vascular analysis according to an embodiment of the present disclosure;

[0017] Figure 7 A schematic diagram showing the intima-media thickness of the region of interest for performing vascular analysis according to an embodiment of the present disclosure;

[0018] Figure 8 A flowchart illustrating Example 2 of a method for performing vascular analysis using an ultrasound imaging device according to an embodiment of the present disclosure is shown. Detailed Implementation

[0019] Embodiments of this disclosure will be described below; however, this disclosure is not intended to be limited to these embodiments. Not all components of this embodiment are always essential. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, numerous details are described to facilitate a better understanding of this disclosure. However, those skilled in the art will readily recognize that some features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this disclosure are not shown or described in the specification to avoid overwhelming the core parts of this disclosure with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0020] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. Simultaneously, the steps or actions in the method description can be rearranged or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various orders in the specification and drawings are merely for the clear description of a particular embodiment and do not imply a mandatory order, unless otherwise stated that a particular order must be followed. The execution order of the steps can be flexibly adjusted as long as it does not affect the execution of each step and the logical relationship between them (e.g., the input of one step depends on the output of another step). A single step can be split into several steps, or several steps can be integrated into a single step for execution; no limitation is made here. The component designations used herein, such as "first," "second," etc., are merely for distinguishing the described objects and do not have any sequential or technical meaning. Unless otherwise specified, the terms "connection" and "linkage" used in this disclosure include both direct and indirect connections (linkages).

[0021] Figure 1 A structural diagram of an ultrasound imaging apparatus according to an embodiment of the present disclosure is shown. This ultrasound imaging apparatus can be used for vascular analysis and has at least a vector blood flow imaging mode. Figure 1 As shown, the ultrasound imaging device may include an ultrasound probe 30 for emitting ultrasound waves toward the region of interest 10 of the blood vessel and receiving corresponding ultrasound echoes to obtain ultrasound echo signals. The ultrasound imaging device may also include transmission and reception control circuits 40, namely a transmission control circuit 410 and a reception control circuit 420, for outputting transmission and reception sequences to the ultrasound probe to control the ultrasound probe to emit ultrasound waves and receive ultrasound echoes.

[0022] The ultrasound imaging device may further include at least one processor 20, which may be configured to control the transmission and reception of the ultrasound probe 30 via the transmit and receive control circuit 40, such that the ultrasound imaging device operates in an ultrasound imaging mode including a vector blood flow imaging mode, and executes methods for vascular analysis according to various embodiments of the present disclosure. The methods for vascular analysis according to various embodiments of the present disclosure may be written as computer-executable instructions and stored in memory 80 for execution by the processor 20 to implement the various steps.

[0023] The ultrasound imaging device may also include a beamforming module 50, an IQ demodulation module 60, and a human-computer interaction device 70.

[0024] Specifically, the ultrasound probe 30 includes a transducer (not shown in the figure) composed of multiple array elements arranged in an array. These elements can be arranged in a row to form a linear array, or in a two-dimensional matrix to form a planar array, or they can form a convex array. The array elements are used to emit ultrasound waves according to an excitation electrical signal, or to convert received ultrasound waves into electrical signals. Therefore, each array element can be used to realize the mutual conversion between electrical pulse signals and ultrasound waves, thereby enabling the emission of ultrasound waves towards the object to be imaged (e.g., the region of interest 10 of a blood vessel), and also to receive echoes of ultrasound waves reflected back from the tissue. During ultrasound detection, the transmission control circuit 410 and the reception control circuit 420 can control which array elements are used to emit ultrasound waves, which array elements are used to receive ultrasound waves, or control the array elements to be used in time-slotted manner for emitting ultrasound waves or receiving echoes of ultrasound waves. Array elements participating in ultrasound emission can be simultaneously excited by electrical signals, thereby emitting ultrasound waves simultaneously; or array elements participating in ultrasound emission can be excited by several electrical signals with a certain time interval, thereby continuously emitting ultrasound waves with a certain time interval.

[0025] The array elements, for example, employ piezoelectric crystals, which convert electrical signals into ultrasonic signals according to the transmission sequence transmitted by the transmission control circuit 410. Depending on the application, the ultrasonic signals may include one or more scanning pulses, one or more reference pulses, one or more driving pulses, and / or one or more Doppler pulses. Depending on the wave morphology, ultrasonic signals may include focused waves, plane waves, and diverging waves, etc.

[0026] The user selects a suitable position and angle by moving the ultrasound probe 30 to emit ultrasound waves to the area of ​​interest 10 of the blood vessel and receives the echo of the ultrasound waves returned from the area of ​​interest 10 of the blood vessel, and outputs an ultrasound echo signal. The ultrasound echo signal is a channel analog electrical signal formed by the receiving array element, which carries amplitude information, frequency information and time information.

[0027] The transmission control circuit 410 generates a transmission sequence according to the control of the processor 20. This transmission sequence controls some or all of the multiple array elements to transmit ultrasound waves towards the region of interest 10 of the blood vessel. The transmission sequence parameters include the position and number of array elements, and the ultrasound beam transmission parameters (e.g., amplitude, frequency, number of transmissions, transmission interval, transmission angle, waveform, focusing position, etc.). In some cases, the transmission control circuit 410 also performs phase delay on the transmitted beams, causing different transmitting array elements to transmit ultrasound waves at different times, so that each transmitted ultrasound beam can be focused on the predetermined region of interest 10. Different operating modes, such as B-image mode, C-image mode, and D-image mode (Doppler mode), may have different transmission sequence parameters. After the echo signal is received by the receiving control circuit 420 and processed by subsequent modules and corresponding algorithms, a B-image reflecting tissue anatomy, a C-image reflecting blood flow information, and a D-image reflecting the Doppler spectrum can be generated.

[0028] Note that in this disclosure, the term "conventional ultrasound imaging mode" is relative to "vector flow imaging mode." Any ultrasound imaging mode that can reflect the structure of the region of interest 10, such as the intima-media structure of the blood vessel, including but not limited to B-image mode and color Doppler ultrasound mode with blood flow information superimposed on B-image mode, falls within the scope of "conventional ultrasound imaging mode." As shown in Figure 2(a), in vector flow imaging mode, the vector velocity of blood flow at various points in the region of interest 10 of the blood vessel can be obtained. The vector velocity of blood flow can include the magnitude of the blood flow (as shown by the length of each arrow in Figure 2(a)) and the direction of the velocity (as shown by the direction of each arrow in Figure 2(a)). As shown in Figure 2(b), in conventional ultrasound imaging mode, the structures in the region of interest 10 of the blood vessel can be seen, such as plaques formed on the inner wall of the carotid artery.

[0029] The "vector velocity" referred to in this disclosure has a magnitude that is the actual velocity of blood flow (such as red blood cells in blood flow), or more closely approximating the actual velocity of blood flow (such as red blood cells in blood flow); and a direction that is the actual flow direction of blood flow (such as red blood cells in blood flow), or more closely approximating the actual flow direction of blood flow (such as red blood cells in blood flow). The direction of the vector velocity can be in the range of 0° to 360° within the imaging plane, and its direction can characterize the actual flow direction of blood flow, as shown by the arrow in Figure 2(a).

[0030] For example, the vector velocity of blood flow can be calculated using methods such as speckle tracking, transverse wave oscillation, or multi-angle deflection transmission / reception based on the Doppler principle.

[0031] Taking the method of obtaining vector velocity through multi-angle deflection transmission / reception as an example, the first ultrasound scan includes emitting ultrasound waves towards the vascular tissue of the object being measured along at least two scanning angles, and the first ultrasound echo signal includes ultrasound echo signals corresponding to the at least two scanning angles. In order to generate a first vector blood flow image based on the first ultrasound echo signal in the vector blood flow mode, the first ultrasound echo signal needs to be processed to obtain the vector velocity of the blood flow. Specifically, the ultrasound echo signals corresponding to the at least two scanning angles can be processed to obtain at least two velocity components corresponding to the at least two scanning angles; by angular synthesis of the at least two velocity components, the vector velocity of the blood flow can be obtained.

[0032] In some embodiments, taking two scanning angles as an example, the ultrasound probe 30 emits ultrasound waves along the first scanning angle towards the region of interest 10 of the blood vessel via the transmission control circuit 410, and receives the first ultrasound echo signal corresponding to the first scanning angle returned from the region of interest 10 of the blood vessel via the receiving control circuit 420. The processor 20 can obtain the first blood flow velocity at the target location (also called the target point) within the region of interest 10 based on the first ultrasound echo signal corresponding to the first scanning angle. This first blood flow velocity is actually the projection component (also called the velocity component) of the vector velocity at the target location on the first scanning angle. Similarly, the ultrasound probe 30 emits ultrasound waves along the second scanning angle towards the region of interest 10 via the transmission control circuit 410, and receives the first ultrasound echo signal corresponding to the second scanning angle returned from the region of interest 10 of the blood vessel via the receiving control circuit 420. The processor 20 can obtain the second blood flow velocity at the target location within the region of interest 10 based on the first ultrasound echo signal corresponding to the second scanning angle. This second blood flow velocity is actually the projection component (also called the velocity component) of the vector velocity at the target location on the second scanning angle. The actual velocity magnitude and direction, i.e., vector velocity, are obtained by angularly synthesizing the first and second blood flow velocities. The above angular synthesis of velocity components corresponding to two different scanning angles is merely illustrative; the synthesis of velocity components corresponding to different scanning angles can be understood with reference to this illustrative explanation. This disclosure does not limit the number of scanning angles, i.e., it does not limit the number of velocity components. Angular synthesis of velocity components corresponding to three or more scanning angles can also be understood with reference to the above-mentioned explanation; it is not exhaustive here.

[0033] For example, vector velocity can also be obtained based on a speckle tracking-based vector blood flow imaging method. This can be achieved by summing absolute differences to calculate the vector velocity using speckle tracking. Furthermore, a more accurate vector velocity can be obtained by combining plane wave emission and speckle tracking.

[0034] For example, vector velocity can also be obtained using a vector blood flow imaging method based on transverse wave oscillation. Specifically, longitudinal velocity is obtained using a traditional Doppler-based calculation method, transverse velocity is calculated using an ultrasound field that generates transverse oscillations and then calculated using an autocorrelation method, and finally, the transverse and longitudinal velocities are combined to obtain the vector velocity.

[0035] The receiving control circuit 420 receives and processes ultrasonic echo signals from the ultrasonic probe 30. The receiving control circuit 420 may include one or more amplifiers, analog-to-digital converters (ADCs), etc. The amplifier amplifies the received echo signal after appropriate gain compensation. The amplifier samples the analog echo signal at predetermined time intervals, converting it into a digitized echo signal. The digitized echo signal still retains amplitude, frequency, and phase information. The data output from the receiving control circuit 420 can be sent to the beamforming module 50 for processing or to the memory 80 for storage.

[0036] The beamforming module 50 is signal-connected to the receiving control circuit 420 and is used to perform beamforming processing such as delay and weighted summation on the echo signal. Because the distance from the ultrasonic receiving point in the tested tissue to the receiving array elements varies, the channel data of the same receiving point output by different receiving array elements has delay differences, requiring delay processing to align the phases and perform weighted summation on the different channel data of the same receiving point to obtain the beamformed ultrasonic image data. The ultrasonic image data output by the beamforming module 50 is also called radio frequency (RF) data. The beamforming module 50 outputs the RF data to the IQ demodulation module 60. In some embodiments, the beamforming module 50 can also output the RF data to the memory 80 for caching or storage, or directly output the RF data to the processor 20 for image processing.

[0037] The beamforming module 50 can perform the above functions in hardware, firmware, or software. For example, the beamforming module 50 may include a central controller circuit (CPU), one or more microprocessor chips, or any other electronic components capable of processing input data according to specific logic instructions. When the beamforming module 50 is implemented in software, it can execute instructions stored on a tangible and non-transitory computer-readable medium (e.g., memory 80) to perform beamforming calculations using any suitable beamforming method. The beamforming module 50 can be integrated into the processor 20 or set up separately; this invention is not limited thereto.

[0038] The IQ demodulation module 60 removes the signal carrier through IQ demodulation, extracts the tissue structure information contained in the signal, and filters to remove noise. The signal obtained at this time is called the baseband signal (IQ data pair). The IQ demodulation module 60 outputs the IQ data pair to the processor 20 for image processing.

[0039] In some embodiments, the IQ demodulation module 60 also caches or saves the IQ data output to the memory 80 so that the processor 20 can read the data from the memory 80 for subsequent image processing.

[0040] The IQ demodulation module 60 can also perform the above functions in hardware, firmware or software. In some embodiments, the IQ demodulation module 60 can also be integrated with the beamforming module 50 in a single chip.

[0041] The processor 20 is configured to process input data according to specific logical instructions. It is a central controller circuit (CPU), one or more microprocessors, a graphics controller circuit (GPU), or any other electronic component. It can control peripheral electronic components according to input instructions or predetermined instructions, or perform data reading and / or saving on the memory 80. It can also process input data by executing programs in the memory 80. For example, it can perform one or more processing operations on the acquired ultrasound data according to one or more operating 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 display on the display of the human-machine interface device 70, or adjusting or limiting the content and form displayed on the display, or adjusting one or more image display settings (e.g., ultrasound images, interface components, positioning areas of interest) displayed on the display.

[0042] When an echo signal is received, the acquired ultrasound data can be processed in real time by the processor 20 during the scan, or it can be temporarily stored in the memory 80 and processed in a near real-time manner during online or offline operation.

[0043] In this embodiment, the processor 20 controls the operation of the transmission control circuit 410 and the reception control circuit 420, for example, controlling the transmission control circuit 410 and the reception control circuit 420 to operate alternately or simultaneously. The processor 20 can also determine a suitable operating mode according to the user's selection or program settings, such as, but not limited to, vector blood flow imaging mode, conventional ultrasound imaging mode, or a custom vector blood flow imaging mode. In this mode, a first ultrasound scan for vector blood flow imaging and a second ultrasound scan for conventional ultrasound imaging can be alternately performed on the region of interest 10 to form a transmission sequence corresponding to the current operating mode. The transmission sequence is then sent to the transmission control circuit 410 so that the transmission control circuit 410 can control the ultrasound probe 30 to emit ultrasound waves using a suitable transmission sequence.

[0044] The processor 20 is also used to process the ultrasound echo signal to generate images corresponding to the operating mode. For example, in B-mode imaging, it generates a grayscale image reflecting the signal intensity variations within the scan range, which reflects the internal anatomical structure of the tissue and is called a B-image, as shown in Figure 2(b). As another example, in vector blood flow imaging mode, it generates a vector blood flow image reflecting the magnitude and direction of blood flow at various points within the scan range, as shown in Figure 2(a). The processor 20 can output the generated images to the display of the human-computer interaction device 70 for display.

[0045] The human-computer interaction device 70 is used for human-computer interaction, that is, outputting visual information and receiving user input; it can receive user input through a keyboard, operation buttons, mouse, trackball, touchpad, etc., or it can use a touch screen integrated with the display; it can output visual information through a display.

[0046] Figure 3 A flowchart illustrating Example 1 of a method for vascular analysis using an ultrasound imaging device according to an embodiment of the present disclosure is shown, wherein the ultrasound imaging device has a vector blood flow imaging mode. Figure 3 As shown, the method can begin with step 301: the ultrasound imaging device is operated in vector flow imaging mode and a first ultrasound scan is performed on the region of interest of the blood vessel. In step 302, a first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of the blood vessel can be acquired. In this disclosure, the region of interest of the blood vessel may include the lesion-corresponding portion (e.g., plaque area) and the peripheral portion (e.g., the vessel wall adjacent to the plaque, the surrounding vessel wall, or other tissues), wherein the lesion-corresponding portion includes a lesion that has already developed and / or a suspected lesion that is suspected to have developed. This not only reduces the control requirements for positioning accuracy in the first ultrasound scan but also acquires echo information from both the lesion-corresponding portion and the peripheral portion. Therefore, in subsequent steps, the effect of the lesion on the lesion-corresponding portion, the effect of the lesion radiating to the peripheral portion, and the comparative relationship between the two effects can be considered, thereby covering the comprehensive physiological mechanism of the lesion and contributing to a more accurate and robust assessment of the lesion's attributes.

[0047] Next, in step 303, the hemodynamic parameters of the region of interest can be determined based on the first ultrasound echo signal or a first vector blood flow image generated in the vector blood flow mode according to the first ultrasound echo signal. Note that "first ultrasound echo signal" can refer to the hemodynamic parameters of the region of interest generated in the vector blood flow mode according to the first ultrasound echo signal. Figure 1 The ultrasound image data output by the beamforming module 50 of the ultrasound imaging device shown, but not yet post-processed by the IQ demodulation module 60, is also called radio frequency data (RF data). The "first vector blood flow image" can represent an image that reflects the vector velocity of blood flow at multiple locations in the region of interest after a series of post-processing steps, such as but not limited to filtering, noise reduction, and rendering, on the ultrasound image data (i.e., radio frequency data) post-processed by the IQ demodulation module 60.

[0048] For ultrasound imaging devices equipped with vector flow imaging modes, acquiring the first ultrasound echo signal or the first vector flow image is convenient, and the hemodynamic parameters of the region of interest can be calculated accordingly. This is compatible with the processing of vector flow imaging modes, and can even utilize the estimation results of some hemodynamic parameters already available in the processing of vector flow imaging modes. In this disclosure, the hemodynamic parameters of the region of interest are intended to represent parameters related to the dynamic conditions of blood flow (e.g., but not limited to blood flow velocity, blood flow velocity gradient distribution, blood flow velocity gradient stability, blood flow velocity disorder, blood flow velocity hindrance characteristics, etc.).

[0049] In step 304, the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest can be determined. In this disclosure, the structural mechanical parameters of the region of interest are intended to represent parameters associated with the structural mechanical properties of the region of interest (such as hardness, strength, toughness, surface regularity, etc.), such as, but not limited to, the hardness of the lesion, the hardness of the tissue or blood vessels surrounding the lesion, and a comparison of the hardness of the lesion with that of the surrounding tissue or blood vessels. In this disclosure, the structural mechanical parameters of the region of interest may also include derived parameters that can indirectly reflect the structural mechanical properties, etc. For example, pulse wave conduction parameters of the blood vessels (such as pulse wave velocity (PWV), pulse wave conduction time (PWTT), etc.) can be used as structural mechanical parameters; the larger the PWV and the smaller the PWTT, the greater the hardness of the surrounding blood vessels. In this disclosure, the biomechanical parameters of the blood vessels in the region of interest are intended to represent the strain parameters of the blood vessels (e.g., but not limited to the vessel wall) and / or derived parameters based on the strain parameters.

[0050] In step 305, the vascular lesion attribute parameters can be determined based on the hemodynamic parameters of the region of interest, the structural mechanics parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest. Specifically, vascular lesions include at least one of plaque, sclerosis, thrombosis, inflammation, stenosis, tumors, and lesions caused by functional vascular diseases. The stability of vascular plaques will be used as an example of a vascular lesion attribute parameter in the following explanation, but it should be understood that vascular lesions are not limited to plaques. By combining parameters from hemodynamics, structural mechanics, and vascular biomechanics to determine the vascular lesion attribute parameters, a comprehensive coverage of the physiological mechanisms of vascular lesions at all stages of development and at all tissue levels can be achieved. This allows for robust and accurate assessment of vascular lesion attributes, significantly reducing missed detections and false positives. Taking the stability properties of vascular plaques as an example, for soft plaques that are prone to rupture, as the load on the soft plaque increases, the lumen undergoes compensatory dilation, which can reduce the degree of luminal stenosis. As a result, the blood flow velocity (v) near the plaque is not significantly different from that of stable lesions. However, the hardness comparison between the corresponding part of the lesion and the surrounding part is significantly different from that of fibrous plaques and calcified plaques (relatively stable vascular plaques). At the same time, soft plaques may be accompanied by ulceration and inflammation, which will lead to changes in the strain parameters of the surrounding vascular wall. By combining the parameters of hemodynamics, structural mechanics and vascular biomechanics, the soft plaque at this stage of development can be accurately identified. The inventors discovered that vulnerable plaques exist in various types, the most common being thin fibrous cap atherosclerotic plaques. Other types include pathological intimal thickening, thick fibrous cap atherosclerotic plaques, calcified plaques with intraluminal calcified stones, intraplaque cholesterol crystals, and angiogenesis. These types of plaques can induce intraluminal angiogenesis or plaque rupture through different mechanisms, and they also exhibit differences in hemodynamic, structural mechanics, and vascular biomechanics parameters. By combining these three parameters, vulnerable plaques with different characteristics can be specifically identified.

[0051] In some embodiments, in addition to the hemodynamic parameters of the region of interest, the structural mechanical parameters and the biomechanical parameters of the vessels in the region of interest can also be determined based on the first ultrasound echo signal or the first vector blood flow image. Thus, when assessing lesions based on ultrasound imaging, a single acquisition operation can be performed in the same mode, i.e., vector blood flow mode, meaning one image is acquired at the same acquisition time. This allows for the determination of the hemodynamic, structural mechanical, and biomechanical parameters of the region of interest, which are synchronously defined in time. This reduces errors in the comprehensive analysis caused by asynchronous acquisition times, and also results in faster processing speeds and lower workload.

[0052] In some embodiments, the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest can also be determined in a conventional ultrasound imaging mode. For example, the ultrasound imaging device can operate in a conventional ultrasound imaging mode and perform a second ultrasound scan on the region of interest of the blood vessel; acquire a second ultrasound echo signal obtained by performing the second ultrasound scan on the region of interest of the blood vessel; and accordingly, determine the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest based on the second ultrasound echo signal or a second ultrasound image generated based on the second ultrasound echo signal in the conventional ultrasound imaging mode. The structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest require higher imaging accuracy than the hemodynamic parameters of the region of interest. Benefiting from the higher imaging accuracy of the conventional ultrasound imaging mode, more accurate structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest can be obtained.

[0053] In some embodiments, the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest can be determined in the following manner: The ultrasound imaging device can operate in conventional ultrasound imaging mode and perform a second ultrasound scan on the region of interest of the blood vessels; acquire a second ultrasound echo signal obtained by performing the second ultrasound scan on the region of interest of the blood vessels; determine one of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest based on the second ultrasound echo signal or a second ultrasound image generated based on the second ultrasound echo signal in the conventional ultrasound imaging mode; determine the other of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest based on the first ultrasound echo signal or the first vector blood flow image. That is, one of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest is determined in conventional ultrasound imaging mode, and the other is determined in vector blood flow mode.

[0054] In some embodiments, the appropriate method for determining the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest can be selected based on the differences in imaging accuracy and acquisition time between the vector imaging mode and the conventional ultrasound imaging mode of the ultrasound imaging device. For example, if the imaging accuracy provided by the vector imaging mode is sufficient, it is preferable to complete the calculation of the above three parameters in a single vector imaging mode to achieve better synchronization. As another example, if the conventional ultrasound imaging mode already provides evaluation items for at least one of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest, the provided readily available evaluation items can be fully utilized to minimize the cost of improving existing ultrasound imaging equipment.

[0055] In some embodiments, it is also possible to obtain ultrasound echo signals or corresponding ultrasound images of the region of interest with higher imaging accuracy without relying on independent conventional ultrasound imaging modes. Specifically, the vector flow imaging mode can be modified. In vector flow imaging mode, the ultrasound imaging device can alternately perform the first ultrasound scan and the second ultrasound scan for conventional ultrasound imaging on the region of interest. In this way, the second ultrasound echo signal obtained by performing the second ultrasound scan on the region of interest of the blood vessel can be acquired alternately. At least one of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessel in the region of interest can be determined based on the second ultrasound echo signal or the second ultrasound image generated from the second ultrasound echo signal. Compared with independent conventional ultrasound imaging modes, this method of alternately performing the first and second ultrasound scans can simultaneously acquire ultrasound echo signals or corresponding ultrasound images of the region of interest with higher imaging accuracy while taking into account the temporal synchronization of the above three parameters.

[0056] In some embodiments, in addition to the three parameters mentioned above, the intima-media thickness (IMT) of the region of interest can be used to collaboratively determine the vascular lesion attribute parameters. Combining the IMT of the region of interest allows for efficient identification of early atherosclerotic lesions, characterized by the formation of a lipid core in the proximal intima-media layer, primarily consisting of abundant proteoglycans and lipid deposits, without the formation of a necrotic core containing necrotic cells. The IMT of the region of interest can be determined based on the first ultrasound echo signal or the first vector flow image, i.e., obtained in vector flow imaging mode, or based on the second ultrasound echo signal or a second ultrasound image generated from the second ultrasound echo signal. Since the repeatability of IMT measurements is generally better than that of parameters such as blood flow velocity, they can be measured separately using a single conventional imaging mode (e.g., but not limited to B-image imaging mode). In some embodiments, similarly, in vector flow imaging mode, the ultrasound imaging device can alternately perform the first ultrasound scan and a second ultrasound scan for conventional ultrasound imaging on the region of interest; the intima-media thickness of the region of interest is determined based on the second ultrasound echo signal or a second ultrasound image generated from the second ultrasound echo signal.

[0057] In some embodiments, the hemodynamic parameters of the region of interest can be a combination of various parameters.

[0058] For example, the hemodynamic parameters of the region of interest can be the blood flow velocity (V) and the vessel wall shear stress (WSS) of the region of interest.

[0059] For example, the shear stress of the vessel wall can be calculated from the vector velocity of blood flow using the following formula (1):

[0060]

[0061] Where τ is WSS, μ is the blood viscosity coefficient, R is the inner diameter of the blood vessel, r is the distance from any point on the cross-section of the blood vessel to the center of the circle, r = R indicates that the measurement point of WSS is on the blood vessel wall, and v represents the velocity component of the blood flow vector velocity in the tangential direction of the blood vessel wall (see...). Figure 4 When the blood vessel wall is straight, the direction is parallel to the blood vessel wall.

[0062] For example, WSS can include average and / or maximum values, which can be the average velocity and / or maximum velocity over a cardiac cycle (or a period of time). This concept of average and / or maximum values ​​also applies to blood flow velocity (V) in the area of ​​interest, which will not be elaborated here. Combining V and WSS allows for the identification of plaque stability at various stages based on hemodynamic mechanisms. For instance, a lower WSS is associated with intimal thickening, making it easier for plaques to grow in areas of lower WSS within the vessel, where mild stenosis may result in insignificant V changes. Vascular lesions typically cause stenosis at the lesion site, and severely stenotic areas exhibit significantly increased blood flow velocity, potentially leading to an increased velocity gradient and indirectly increasing WSS. As plaque develops and stenosis worsens, a high WSS can occur locally within the plaque, increasing the likelihood of plaque rupture.

[0063] For example, the hemodynamic parameters of the region of interest may include the blood flow velocity (V), vessel wall shear stress (WSS), and oscillating shear index (OSI) of the region of interest.

[0064] In some embodiments, OSI can be calculated using the following formula (2):

[0065]

[0066] OSI indicates the degree of change in WSS direction over a period of time (e.g., within one cardiac cycle T). It can be a value ranging from 0 to 0.5. A higher OSI indicates more frequent changes in WSS direction, reaching a maximum of 0.5 in the most frequent extreme cases. In other words, a larger OSI indicates more frequent changes in WSS direction, and compared to a simply larger WSS, it significantly increases the likelihood of plaque lesions. Therefore, combining V, WSS, and OSI allows for a more accurate assessment of plaque stability.

[0067] For example, the hemodynamic parameters of the region of interest may include the blood flow velocity (V), vessel wall shear stress (WSS), and the degree of blood flow dispersion (TUR) in the mid-to-downstream region of interest (see [reference]). Figure 4 ).

[0068] In some embodiments, TUR can be the discreteness in a two-dimensional plane, which can be calculated using the following formulas (3) and (4):

[0069]

[0070]

[0071] Where, θ i Let TUR be the angle of the blood flow velocity vector at the i-th point in the two-dimensional plane, and N be the number of blood flow velocity vectors (i.e., the number of points in the region of interest). TUR is a value that varies between 0 and 1. The larger the TUR, the higher the degree of blood flow dispersion. When it is equal to or close to 0, it is laminar or near-laminar flow. The mid-to-downstream region of interest is usually located downstream of the lesion, such as downstream of a plaque lesion. If a large TUR is present, it will increase the likelihood of plaque damage.

[0072] For example, the hemodynamic parameters of the region of interest may include the blood flow velocity (V), vessel wall shear stress (WSS), and downstream vascular resistance (R) of the region of interest. The downstream vascular resistance (R) of the region of interest is usually associated with vascular aging (fragility), stenosis, and / or inflammation, and correspondingly, greater vascular resistance downstream of the plaque increases the likelihood of plaque damage.

[0073] In some embodiments, the structural mechanical parameters of the region of interest include a stiffness contrast parameter of the region of interest and pulse wave conduction parameters of the blood vessel. Within the region of interest, the greater the stiffness of the plaque-corresponding portion and the smaller the stiffness of the peripheral portion (e.g., but not limited to peripheral blood vessels), the better the plaque stability; conversely, the softer the plaque-corresponding portion compared to the peripheral portion, the worse the plaque stability. Furthermore, for plaque-corresponding portions of the same stiffness, the greater the stiffness of the peripheral blood vessel, the worse the plaque stability.

[0074] For example, pulse wave conduction parameters of blood vessels can include pulse wave velocity (PWV) and pulse wave conduction time (PWTT). Pulse wave conduction is an important non-invasive indicator of the degree of arteriosclerosis. The faster the pulse wave conduction, the worse the degree of arteriosclerosis, and correspondingly, the worse the plaque stability.

[0075] Figures 5(a) and 5(b) show schematic diagrams for calculating PWTT according to embodiments of the present disclosure.

[0076] The propagation of pulse waves in blood vessels causes changes in blood flow velocity, so the propagation of pulse waves can be deduced from the blood flow velocity. Vector flow imaging provides the blood flow velocity value and direction (the vector velocity of blood flow is obtained through multi-angle deflection transmission and reception); therefore, the change of blood flow velocity at each point within the blood vessel over time is known.

[0077] Two points along the axial direction of the blood vessel can be selected as detection points, as shown in Figure 5(a) (where 110 represents the vessel wall). Detection points a and b can be located on the central axis of the blood vessel (the solid line between the two vessel walls 110 in Figure 5(a)) and on opposite sides of the ultrasound flow map, maximizing the distance between a and b to improve the accuracy of PWTT and PWV. Alternatively, detection points a and b can be determined based on user input (the user selects a and b on the ultrasound flow map).

[0078] This embodiment uses the change of blood flow velocity over time as an example to illustrate the concept. Figure 5(b) shows the blood flow velocity curves La and Lb for two detection points (e.g., a and b). The pulse wave conduction time (PWTT) or pulse wave velocity (PWV) can be obtained based on the change of blood flow velocity over time at at least two detection points (e.g., the blood flow velocity curves). The calculation methods for PWTT and PWV are explained below.

[0079] In some embodiments, the phase time difference between blood flow velocity curves La and Lb at at least two detection points can be calculated, and the pulse wave propagation time (PWTT) can be determined based on this phase time difference. The phase time difference of the blood flow velocity curves includes the time difference between the moment when the blood flow velocity at the first detection point changes to a first characteristic value and the moment when the blood flow velocity at the second detection point changes to a second characteristic value within the same cardiac cycle. The first and second characteristic values ​​have the same phase or are synchronized within the same cardiac cycle. The first and second characteristic values ​​can be selected as needed; for example, taking the maximum value of both characteristics facilitates calculation. That is, within the same cardiac cycle, if the moment corresponding to the maximum blood flow velocity in one blood flow velocity curve La is t1, and the moment corresponding to the maximum blood flow velocity in another blood flow velocity curve Lb is t2, then the phase time difference between these two blood flow velocity curves is |t1-t2|. |t1-t2| is the time it takes for the pulse wave to propagate from detection point a to detection point b (pulse wave propagation time).

[0080] In some embodiments, the pulse wave velocity (PWV) can be calculated based on the pulse wave transit time (PWTT). Specifically, the distance between at least two detection points a and b in the blood vessel can be obtained, which is the propagation distance of the pulse wave between the at least two detection points. Then, the PWV can be calculated based on the PWTT and the distance. In some embodiments, the PWV can also be calculated without relying on the PWTT. Specifically, the time when the blood flow velocity at at least two detection points a and b reaches the third characteristic value can be obtained based on the blood flow velocity curves La and Lb of the at least two detection points a and b; the time when the blood flow velocity at the at least two detection points reaches the third characteristic value and the distance between the at least two detection points are fitted, and the PWV is obtained by differentiating the fitted line. The third characteristic value can be set as needed; for example, the third characteristic value is the maximum value, i.e., the time when the blood flow velocity at each detection point reaches the maximum value is obtained.

[0081] In some embodiments, the biomechanical parameters of the blood vessels in the region of interest include the strain parameters of the vessel wall (e.g., Figure 6 (as shown) and / or derived parameters based on the strain parameters.

[0082] Ultrasound images in various imaging modes, such as but not limited to vector flow images and B-mode images, can be used to identify the location of the vessel wall and calculate vessel strain. Typically, the grayscale value of the vessel wall in an ultrasound B-mode image is higher than that of other tissues and much higher than that of blood flow; therefore, this image feature can be used to identify the vessel wall location. In vector flow images, the edges of blood flow energy are in contact with the vessel wall; this information can also be used to identify the vessel wall location. Here, the B-mode image used to identify the vessel wall location can be B-mode grayscale image data, or data from any intermediate stage in the B-mode imaging process, such as RF signals, data before logarithmic compression, etc.

[0083] Strain refers to the change in shape of an object under the action of force. It can be expressed as a percentage of the original length, and can be calculated using the following formula (5):

[0084]

[0085] Where S is the strain, ΔL is the change in length, L is the length after the change, and L0 is the initial length.

[0086] Strain rate refers to the rate at which an object changes shape under the action of force, that is, the strain per unit time, which can be calculated by the following formula (6):

[0087]

[0088] Among them, S R Let ΔS be the strain rate, Δt be the change in strain, Δt be the time interval, and ΔV be the velocity. Any of the strain variables and strain rates defined above for the blood vessel wall can serve as examples of strain parameters for the blood vessel wall.

[0089] Vascular strain parameters can be calculated using speckle tracking technology. For example, the location of the blood vessel wall in an ultrasound image can be identified, one or more points of interest can be selected from the location of the blood vessel wall, and motion tracking can be performed on the points of interest to obtain information on the positional changes of the points of interest within one or more cardiac cycles. The processor can then calculate the strain parameters of the blood vessel wall based on the positional change information, such as the strain and / or strain rate of the blood vessel wall.

[0090] A concrete example could be generating a B-image of the long axis of the blood vessel, then obtaining the vessel wall and selecting points of interest on the vessel wall. Using a tracking algorithm, information on the positional changes of these points of interest within one or more cardiac cycles can be obtained. Based on this, the distance between two adjacent points of interest on the first frame image is used as a benchmark, and then the distance between two adjacent points in each subsequent frame is calculated to obtain the strain and strain rate of the vessel wall.

[0091] Figure 7 The intima-media thickness (IMT) 701 of the region of interest for vascular analysis according to an embodiment of this disclosure is shown, as follows: Figure 7 As shown, the two "+" signs represent the measurement points for IMT, and the length of the line connecting the two "+" signs represents the intima-media thickness (IMT). The boundaries of the intima-media are also marked with lines for comparison with IMT 701. Pathological intima thickening may be associated with early-stage progressive atherosclerotic lesions or may be related to inflammatory cell invasion, leading to poorer plaque stability.

[0092] The following explanation uses plaque as an example to illustrate the lesion attribute parameters.

[0093] In some embodiments, the lesion attribute parameters can characterize whether the lesion is a plaque. When the lesion is a plaque, the lesion attribute parameters can also automatically classify the plaque into three categories: stable plaque; potentially unstable plaque requiring further confirmation; and unstable plaque requiring further confirmation. There are no clear guidelines or standards for diagnosing plaque stability. These three categories provide an exemplary reference indicator, although they cannot be used as diagnostic conclusions, but they provide doctors with diagnostic references and appropriate margins. Specifically, the first category, stable plaques, means that no further confirmation, such as angiography, is required; follow-up is sufficient. The second category, potentially unstable plaques, suggests that doctors need to further manually confirm whether the plaque should be classified as unstable, thus avoiding the machine's arbitrary classification as stable leading to missed positive results, and also avoiding the arbitrary classification as unstable leading to the introduction of unnecessary confirmation methods, such as, but not limited to, angiography. The third category, unstable plaques, clearly indicate that the plaque is in a vulnerable (or even prone to rupture) state, requiring further confirmation of the plaque's unstable state to assist doctors in making specific diagnostic and treatment plans.

[0094] like Figure 8 As shown, in the case of plaque lesions, the processor can automatically perform the above three-classification of lesion attribute parameters using the following methods. Specifically, a first threshold and a second threshold can be set, wherein the second threshold can be less than the first threshold and is used to determine whether the plaque is in a stable state or a non-stable state (including unstable state and potentially unstable state). Further, the first threshold is used to determine whether an unstable plaque is in an unstable state or a potentially unstable state. In step 305, the lesion attribute parameters of the blood vessel can be determined based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessel in the region of interest.

[0095] In step 801, the determined lesion attribute parameters can be compared with a second threshold. If the lesion attribute parameters are less than the second threshold (yes in step 801), the structure is determined to be a plaque and the plaque is in a stable state (step 804).

[0096] If the lesion attribute parameter is greater than the second threshold (No in step 801), the lesion attribute parameter is further compared with the first threshold. If the lesion attribute parameter is less than the first threshold (Yes in step 802), the structure is determined to be a plaque, and the plaque is potentially unstable and requires further confirmation (Step 803). If the lesion attribute parameter is greater than the first threshold (No in step 802), the structure is determined to be a plaque, and the plaque is unstable and requires further confirmation.

[0097] In some embodiments, the lesion attribute parameters can be used to grade plaque stability. That is, the lesion attribute parameters can be implemented as grading parameters for plaque stability, with different grades corresponding to different plaque stability levels. For example, a plaque stability index y can be defined. i (i represents the sample number), and the patches are classified according to the patch stability index. The stability index y is used below. i Taking {0,1} as an example, 0 indicates that the patch is stable and 1 indicates that the patch is unstable.

[0098] For example, if it is divided into 4 levels:

[0099] When the stability index y of patch i i When ∈[0 0.25), patch i is level 1;

[0100] When the stability index y of patch i i When ∈ [0.25 0.5), patch i is level 2;

[0101] When the stability index y of patch i i When ∈ [0.5 0.75), patch i is level 3;

[0102] When the stability index y of patch i i When ∈[0.75 1], patch i is level 4.

[0103] Level 1 is relatively stable, while Level 4 is the least stable.

[0104] In some embodiments, corresponding prompts can be displayed to the user on the screen based on the lesion attribute parameters. The prompts include the necessity for further confirmation, and if confirmation is required, also include the confirmation method, which may include angiography. For example, the prompts may indicate the stability level of the plaque, or suggest the next steps required, such as, but not limited to, manually verifying whether plaque i is unstable, and using auxiliary imaging methods (e.g., but not limited to, angiography) to confirm the specific unstable state of plaque i.

[0105] In some embodiments, vascular lesion attributes, such as but not limited to plaque stability index, can be constructed as a model based on hemodynamic parameters of the region of interest, structural mechanical parameters of the region of interest, and biomechanical parameters of the blood vessels in the region of interest. Using these parameters as input, the model can be used to determine lesion attribute parameters.

[0106] The following explanation uses seven parameters as input parameters for the model: blood flow velocity (V), WSS, OSI, TUR, stiffness contrast parameter (E), PWV, and vessel wall strain (S) in the region of interest. However, it should be noted that this disclosure has already provided various combinations of input parameters, and the model construction here can also be applied to other combinations of input parameters, which will not be elaborated here.

[0107] As a simplified implementation of the model, it can be constructed as a linearly classifiable model, as shown in formula (7):

[0108] y=w1*V+w2*WSS+w3*OSI+w4*Tur+w5*E+w6*PWV+w7*S Formula (7)

[0109] w1, w2, w3, w4, w5, w6, and w7 are the weighting coefficients for the seven parameters: V, WSS, OSI, TUR, the hardness comparison parameter (E) of the area of ​​interest, PWV, and strain (S) of the vessel wall, respectively. y represents the plaque stability index. If the plaque stability index has a good linear correlation with these seven parameters, then the linear model defined by formula (7) can perform well. These seven weighting coefficients can be obtained through fitting.

[0110] In some embodiments, although these seven parameters are all clinically closely related to plaque stability, the physiological mechanisms of plaque stability are complex, and these seven parameters can be used as input parameters for the learning model. In some embodiments, the learning model can be based on convolutional neural networks, for example, using sigmoid as the activation function and cross-entropy as the loss function for training.

[0111] In some embodiments, the first and second thresholds described above can be set based on the doctor's experience data, for example, the second threshold is 0.25 and the first threshold is 0.75. In other embodiments, a trained model can be used to determine the plaque stability index for samples manually labeled as stable, possibly unstable, and unstable, and cluster analysis can be performed with reference to the category labels to obtain the first and second thresholds.

[0112] This disclosure also provides a computer-readable storage medium having computer-executable instructions thereon that, when executed by a processor, implement a method for vascular analysis according to various embodiments of this disclosure.

[0113] This part or all of the processing can be implemented as a computer program. The program described above can be stored in various types of non-transitory computer-readable media and can be provided to a computer. Non-transitory computer-readable media includes various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., floppy disks, magnetic tapes, and hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), read-only memory (CD-ROM), CD-R, CD-R / W, semiconductor memory (e.g., mask ROM, programmable ROM (PROM), erasable PROM (EPROM), flash memory ROM, and random access memory (RAM)). The program can be provided to a computer via various types of transient computer-readable media. Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transient computer-readable media can provide the program to a computer via wired communication paths (e.g., wires and optical fibers) or wireless communication paths.

[0114] This disclosure is not limited to the above embodiments and can be modified as needed without departing from the scope of the invention.

Claims

1. A method for blood vessel analysis applied to an ultrasound imaging device with vector flow imaging mode, characterized in that, include: This enables the ultrasound imaging device to operate in vector blood flow imaging mode and perform a first ultrasound scan on the region of interest of the blood vessel; Acquire the first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of the blood vessel; Based on the first ultrasound echo signal or a first vector blood flow image generated in the vector blood flow imaging mode according to the first ultrasound echo signal, the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest are determined; wherein, the hemodynamic parameters of the region of interest include: blood flow velocity and vessel wall shear stress in the region of interest, as well as the oscillatory shear index and the blood flow dispersion in the middle and lower reaches of the region of interest; the structural mechanical parameters of the region of interest include the stiffness contrast parameters of the region of interest and the pulse wave conduction parameters of the blood vessels; and the biomechanical parameters of the blood vessels in the region of interest include the strain parameters of the vessel wall. Based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest, the same lesion attribute parameters of the blood vessels are jointly determined. This includes weighting the blood flow velocity, shear stress of the blood vessel wall, oscillatory shear index, blood flow dispersion in the middle and lower reaches of the region of interest, stiffness comparison parameters of the region of interest, pulse wave conduction parameters of the blood vessels, and strain parameters of the blood vessel wall to obtain the lesion attribute parameters of the blood vessels.

2. The method according to claim 1, characterized in that, The hemodynamic parameters of the region of interest also include the vascular resistance of the region of interest.

3. The method according to claim 1, characterized in that, The vector velocity of blood flow is determined based on the first ultrasound echo signal, and the shear stress of the blood vessel wall is calculated based on the vector velocity of blood flow and the blood viscosity coefficient.

4. The method according to claim 1, characterized in that, Determining the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest includes: This enables the ultrasound imaging device to operate in conventional ultrasound imaging mode and perform a second ultrasound scan on the region of interest of the blood vessel. Acquire the second ultrasound echo signal obtained by performing the second ultrasound scan on the region of interest of the blood vessel; Based on the second ultrasound echo signal or a second ultrasound image generated in the conventional ultrasound imaging mode based on the second ultrasound echo signal, determine the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest.

5. The method according to claim 1, characterized in that, Determining the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest includes: This enables the ultrasound imaging device to operate in conventional ultrasound imaging mode and perform a second ultrasound scan on the region of interest of the blood vessel. Acquire the second ultrasound echo signal obtained by performing the second ultrasound scan on the region of interest of the blood vessel; Based on the second ultrasound echo signal or a second ultrasound image generated in the conventional ultrasound imaging mode based on the second ultrasound echo signal, determine one of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest. Based on the first ultrasound echo signal or the first vector blood flow image, determine another of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest.

6. The method according to any one of claims 1-5, characterized in that, The lesion includes at least one of plaque, sclerosis, thrombosis, inflammation, stenosis, tumor and functional vascular disease. The area of ​​concern includes the lesion-corresponding part and the surrounding part. The lesion-corresponding part includes the lesion part that has already developed a lesion and / or the suspected lesion part that is suspected of developing a lesion.

7. The method according to any one of claims 1-5, characterized in that, The biomechanical parameters of the blood vessels in the region of interest also include derived parameters based on the strain parameters.

8. The method according to any one of claims 1-5, characterized in that, The lesion attribute parameters characterize whether the lesion is a plaque, and if the lesion is a plaque, further characterize whether the plaque is in a stable state, a potentially unstable state requiring further confirmation, or an unstable state requiring further confirmation; and / or The lesion attribute parameters are plaque stability grading parameters, with different grades corresponding to different plaque stability. The method further includes: presenting corresponding prompt information to the user on a display based on the lesion attribute parameters.

9. The method according to claim 8, characterized in that, The prompt message indicates the necessity for further confirmation, and if confirmation is required, it also includes the confirmation method, which includes angiography.

10. The method according to any one of claims 1-5, characterized in that, Also includes: The intima-media thickness of the region of interest is determined based on the first ultrasound echo signal or the first vector blood flow image, or based on the second ultrasound echo signal or a second ultrasound image generated according to the second ultrasound echo signal. The determination of the lesion attribute parameters of the blood vessels based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest specifically includes: The common lesion attribute parameters are determined based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, the biomechanical parameters of the blood vessels in the region of interest, and the determined intima-media thickness of the region of interest.

11. The method according to any one of claims 1-5, characterized in that, Also includes: In vector blood flow imaging mode, the ultrasound imaging device alternately performs the first ultrasound scan and the second ultrasound scan for conventional ultrasound imaging on the region of interest. Acquire the second ultrasound echo signal obtained by performing the second ultrasound scan on the region of interest of the blood vessel; Based on the second ultrasound echo signal or a second ultrasound image generated from the second ultrasound echo signal, determine at least one of the structural mechanical parameters of the region of interest and the biomechanical parameters of the blood vessels in the region of interest.

12. A method for vascular analysis, applied to an ultrasound imaging device with a vector blood flow imaging mode, characterized in that, include: This enables the ultrasound imaging device to operate in vector blood flow imaging mode and perform a first ultrasound scan on the region of interest of the blood vessel; Acquire the first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of the blood vessel; Based on the first ultrasound echo signal or a first vector blood flow image generated in the vector blood flow imaging mode according to the first ultrasound echo signal, the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest are determined; wherein, the hemodynamic parameters of the region of interest include: blood flow velocity and vessel wall shear stress in the region of interest, as well as the oscillatory shear index and the blood flow dispersion in the middle and lower reaches of the region of interest; the structural mechanical parameters of the region of interest include the stiffness contrast parameters of the region of interest and the pulse wave conduction parameters of the blood vessels; and the biomechanical parameters of the blood vessels in the region of interest include the strain parameters of the vessel wall. In vector blood flow imaging mode, the ultrasound imaging device alternately performs the first ultrasound scan and the second ultrasound scan for conventional ultrasound imaging on the region of interest. The thickness of the intima-media membrane in the region of interest is determined based on the second ultrasound echo signal or a second ultrasound image generated according to the second ultrasound echo signal in the conventional ultrasound imaging mode. The lesion attribute parameters are determined by combining the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, the biomechanical parameters of the blood vessels in the region of interest, and the determined intima-media thickness of the region of interest.

13. A method for vascular analysis, applied to an ultrasound imaging device with a vector blood flow imaging mode, characterized in that, include: This enables the ultrasound imaging device to operate in vector blood flow imaging mode and perform a first ultrasound scan on the region of interest of the blood vessel; Acquire the first ultrasound echo signal obtained by performing the first ultrasound scan on the region of interest of the blood vessel; Based on the first ultrasound echo signal or a first vector blood flow image generated in the vector blood flow imaging mode according to the first ultrasound echo signal, the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest are determined; wherein, the hemodynamic parameters of the region of interest include: blood flow velocity and vessel wall shear stress in the region of interest, as well as the oscillatory shear index and the blood flow dispersion in the middle and lower reaches of the region of interest; the structural mechanical parameters of the region of interest include the stiffness contrast parameters of the region of interest and the pulse wave conduction parameters of the blood vessels; and the biomechanical parameters of the blood vessels in the region of interest include the strain parameters of the vessel wall. Based on the hemodynamic parameters of the region of interest, the structural mechanical parameters of the region of interest, and the biomechanical parameters of the blood vessels in the region of interest, a learning model is used to determine the lesion attribute parameters.

14. The method according to claim 13, characterized in that, Also includes: Set a first threshold and a second threshold; The determined lesion attribute parameters are compared with the first threshold and the second threshold. If the lesion attribute parameter is greater than the first threshold, the structure is determined to be a plaque, and the plaque is unstable and requires further confirmation. If the lesion attribute parameter is less than the second threshold, the structure is determined to be a plaque and the plaque is in a stable state. If the lesion attribute parameters are between the second threshold and the first threshold, the structure is determined to be a plaque, and the plaque is in a state that may be unstable and requires further confirmation.

15. An ultrasound imaging device for vascular analysis, characterized in that, The ultrasound imaging device includes: An ultrasound probe is used to emit ultrasound waves toward the area of ​​interest in a blood vessel and receive the corresponding ultrasound echoes to obtain ultrasound echo signals. A transmit and receive control circuit is used to output a transmit and receive sequence to the ultrasonic probe to control the ultrasonic probe to transmit ultrasonic waves and receive ultrasonic echoes. At least one processor, configured as follows: The transmission and reception of the ultrasound probe are controlled by the transmission and reception control circuit, enabling the ultrasound imaging device to operate in ultrasound imaging modes, including vector blood flow imaging mode; and Perform the method for vascular analysis according to any one of claims 1-14.

16. A non-volatile computer storage medium having stored computer-readable instructions thereon, which, when executed by at least one processor, implement the method for vascular analysis according to any one of claims 1-14.

Images