An ultrasound imaging method and apparatus
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- INST OF ACOUSTICS CHINESE ACAD OF SCI
- Filing Date
- 2023-11-21
- Publication Date
- 2026-07-21
AI Technical Summary
In ultrasound imaging of various non-homogeneous compositions, the use of uniform sound velocity can lead to artifacts or incorrect scattering point locations in the imaging results. This is especially true in transcranial ultrasound imaging, where the difference in sound velocity between the skull and intracranial tissues results in decreased imaging accuracy.
Ultrasonic emission and echo data of the object under test are acquired by an ultrasonic probe array, depth migration is performed, the response matrix of each migration depth layer is calculated, and the optimal sound velocity is determined by an optimization algorithm for imaging.
It effectively eliminates artifacts in the imaging results, improves imaging accuracy and quality, and in particular corrects the inhomogeneity of acoustic parameters of the skull and soft tissues in transcranial ultrasound imaging, ensuring the accuracy of the images.
Smart Images
Figure CN117598734B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of ultrasound imaging technology, and in particular to an ultrasound imaging method and apparatus. Background Technology
[0002] An ultrasound probe array emits ultrasound waves toward the object under test and then receives the echo generated by the interaction with the object to obtain acoustic impedance structural parameters, thereby achieving imaging and serving as imaging evidence for various purposes such as auxiliary diagnosis.
[0003] Traditional ultrasound imaging methods typically employ a uniform sound velocity, such as 1540 m / s commonly used in human tissue for dynamic focusing and depth information calibration. However, in ultrasound imaging of various non-homogeneous compositions, the significant differences in sound velocities among different material compositions mean that using the same sound velocity for imaging can cause strong distortion effects, resulting in artifacts or incorrect scattering point locations in the image results. Summary of the Invention
[0004] This application provides an ultrasound imaging method and apparatus.
[0005] Firstly, an ultrasound imaging method is provided, the method comprising:
[0006] The first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test are obtained by an ultrasonic probe array.
[0007] Based on the first ultrasonic emission data and the first ultrasonic echo data, depth migration is performed to obtain second ultrasonic emission data and second ultrasonic echo data corresponding to multiple migration depth layers; the second ultrasonic emission data and second ultrasonic echo data corresponding to any i-th migration depth layer include the sound velocity of ultrasonic waves in the i-th migration depth layer.
[0008] Calculate the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer;
[0009] Based on a predetermined range of sound speeds, the sound speed of the response matrix corresponding to the i-th deep migration layer is optimized by taking the minimum half-width of the signal intensity on the sub-diagonal of the response matrix corresponding to the i-th deep migration layer as the convergence target, thereby obtaining the optimized sound speed corresponding to the i-th migration depth layer.
[0010] In one possible implementation, the ultrasonic probe array is used to acquire the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area of the object under test in a full matrix acquisition mode.
[0011] In one possible implementation, the step of performing depth migration based on the first ultrasonic emission data and the first ultrasonic echo data to obtain second ultrasonic emission data and second ultrasonic echo data corresponding to each of multiple migration depth layers includes:
[0012] Based on the first ultrasonic emission data and the first ultrasonic echo data, and the depth coordinates of each of the plurality of migration depth layers in the target region, the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the plurality of migration depth layers are calculated using the acoustic wave equation; wherein the first ultrasonic emission data and the first ultrasonic echo data are regarded as the 0th migration depth layer in the target region.
[0013] In one possible implementation, the step of calculating the second ultrasonic emission data and second ultrasonic echo data corresponding to each of the plurality of migration depth layers in the target region using the acoustic wave equation, based on the first ultrasonic emission data and the first ultrasonic echo data, and the depth coordinates of each of the plurality of migration depth layers located in the target region, includes:
[0014] The first ultrasonic emission data and the first ultrasonic echo data located in the time domain are converted to the frequency-wavenumber domain;
[0015] Based on the first ultrasonic emission data and the first ultrasonic echo data located in the frequency-wavenumber domain, and the depth coordinates of each of the plurality of migration depth layers in the target region, the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the plurality of migration depth layers are calculated using the acoustic wave equation.
[0016] In one possible implementation, the step of calculating the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer includes: calculating the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0017] The response matrix corresponding to the i-th migration depth layer is obtained by summing the tensor products of the frequencies of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0018] In one possible implementation, calculating the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer includes:
[0019] The second ultrasonic echo data and the second ultrasonic emission data corresponding to the i-th migration depth layer are converted to the frequency domain;
[0020] Based on the second ultrasonic echo data and the second ultrasonic emission data located in the frequency domain corresponding to the i-th migration depth layer, calculate the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0021] In one possible implementation, the sound velocity of the response matrix corresponding to the i-th deep migration layer is optimized using a bisection method or the golden section method.
[0022] In a second aspect, an ultrasound imaging device is provided, the device comprising:
[0023] The data acquisition unit is used to acquire the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test through the ultrasonic probe array;
[0024] The data migration unit is used to perform depth migration based on the first ultrasonic emission data and the first ultrasonic echo data to obtain second ultrasonic emission data and second ultrasonic echo data corresponding to each of the multiple migration depth layers; the second ultrasonic emission data and second ultrasonic echo data corresponding to any i-th migration depth layer include the sound velocity of the ultrasonic wave in the i-th migration depth layer.
[0025] The data calculation unit is used to calculate the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0026] The data optimization unit is used to optimize the sound velocity of the response matrix corresponding to the i-th deep migration layer based on a predetermined sound velocity range and with the minimum half-width of the signal intensity on the sub-diagonal of the response matrix corresponding to the i-th deep migration layer as the convergence target, so as to obtain the optimized sound velocity corresponding to the i-th migration depth layer.
[0027] An ultrasound imaging unit is used to obtain the imaging result of the i-th migration depth layer based on the optimization sound velocity corresponding to the i-th migration depth layer and the response matrix corresponding to the i-th migration depth layer, and to obtain the target imaging result based on the imaging results corresponding to each of the multiple migration depth layers.
[0028] Thirdly, a computer-readable storage medium is provided having a computer program stored thereon, wherein when the computer program is executed in a computing device, the computing device performs the method described in any one of the first aspects.
[0029] Fourthly, a computing device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in any one of the first aspects.
[0030] In the technical solution provided in this application, to avoid the difference in the preferred imaging sound velocity corresponding to different tissue structure layers in the test object, depth migration is performed on the acquired first ultrasonic emission data and first ultrasonic echo data to obtain the data corresponding to each of the i-th migration depth layers in the target area of the test object, namely the i-th second ultrasonic emission data and second ultrasonic echo data; then, the response matrix corresponding to the i-th migration depth layer is calculated, and the sound velocity of the ultrasonic wave used for imaging in the i-th migration depth layer is optimized to obtain the optimized sound velocity of the ultrasonic wave in the i-th migration depth layer; subsequently, ultrasonic imaging is performed using the optimized sound velocity and response matrix corresponding to each of the i-th migration depth layers to obtain the one-dimensional imaging result corresponding to the i-th migration depth layer; finally, based on the one-dimensional imaging results corresponding to multiple migration depth layers and the depth coordinates of each migration depth layer, a two-dimensional target imaging result is obtained, thereby eliminating the artifact problem in the imaging result caused by using the same sound velocity during imaging. Attached Figure Description
[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 This is a schematic diagram of the structure of an ultrasound imaging system provided in an embodiment of this application;
[0033] Figure 2 A schematic flowchart of an ultrasound imaging method provided in an embodiment of this application;
[0034] Figure 3 This is a schematic diagram of a full-matrix ultrasonic acquisition method provided as an example in an embodiment of this application;
[0035] Figure 4 for Figure 1 A magnified view of a portion of the image;
[0036] Figure 5 This is an example of an embodiment of the present application providing an energy comparison diagram of the response matrices corresponding to different sound speeds;
[0037] Figure 6 An optimized sound velocity profile obtained based on the ultrasonic imaging method provided in this application is provided as an example of an embodiment of this application.
[0038] Figure 7 A comparison diagram of imaging results obtained by the ultrasound imaging method provided in this application and other methods is provided as an example of an embodiment of this application.
[0039] Figure 8 A schematic diagram of the structure of an ultrasound imaging device provided in an embodiment of this application is shown. Detailed Implementation
[0040] The solution provided in this specification will now be described with reference to the accompanying drawings.
[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be described below in conjunction with the accompanying drawings. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0042] In the description of the embodiments of this application, the words "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a specific manner.
[0043] In the description of the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. Furthermore, unless otherwise stated, the term "multiple" means two or more.
[0044] Furthermore, in the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.
[0045] An ultrasound probe array emits ultrasound waves toward the object under test and then receives the echo generated by the interaction with the object to obtain acoustic impedance structural parameters, thereby achieving imaging and serving as imaging evidence for various purposes such as auxiliary diagnosis.
[0046] Traditional ultrasound imaging methods typically employ a uniform sound velocity, such as 1540 m / s commonly used in human tissue for dynamic focusing and depth information calibration. However, in ultrasound imaging of various non-homogeneous bodies, such as transcranial ultrasound in the medical field, the sound velocity in the skull is much higher than that in intracranial brain tissue. Distortion and attenuation of the ultrasound signal caused by the skull will lead to decreased accuracy and quality in transcranial imaging, affecting physicians' screening and diagnosis of brain diseases. Even if imaging can be performed through the thinnest part of the human skull—the temporal window—the influence of the skull cannot be ignored. Failure to consider these differences during reconstruction may result in artifacts or incorrect scattering point locations in the imaging results.
[0047] Therefore, effective transcranial ultrasound imaging methods must address the issue of inhomogeneous acoustic parameters between the skull and soft tissues. This requires acquiring the sound velocity characteristics of different intracranial tissues and imaging them separately to ensure image accuracy. To this end, this invention provides an ultrasound imaging method and apparatus that can be used in fields such as transcranial ultrasound imaging correction.
[0048] Figure 1 This is one of the structural diagrams of an ultrasound imaging system 100 provided in an embodiment of this application. Figure 1 The structural diagrams shown are only used to assist in describing the technical solutions provided in the embodiments of this application, and are not intended to limit the solutions of the embodiments of this application.
[0049] The ultrasound imaging system 100 may include a computing device, an ultrasound machine, and an ultrasound probe array. The computing device controls the sound wave emission mode of the ultrasound machine, causing the ultrasound probe array connected to the ultrasound machine to emit ultrasound waves toward the object under test, and simultaneously collects the first ultrasound emission data corresponding to the emitted ultrasound waves and the first ultrasound echo data acquired. The ultrasound probe array and the target object under test are coupled through a coupling medium.
[0050] Figure 2 This diagram illustrates a flowchart of an ultrasound imaging method provided in an embodiment of this application. See also... Figure 2 As shown, the method may include, but is not limited to, some or all of the steps S201 to S209 below. The method can be executed by any device, platform, equipment, or cluster of devices with computing / processing capabilities, such as by... Figure 1 The example computing device in the text is executed.
[0051] Step S201: Obtain the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test through an ultrasonic probe array.
[0052] For example, the computing device can control the sound wave emission mode of the ultrasonic machine, causing the ultrasonic probe array connected to the ultrasonic machine to emit ultrasonic waves toward the object under test, while simultaneously collecting the first ultrasonic emission data and the acquired first ultrasonic echo data corresponding to the emitted ultrasonic waves. The methods for acquiring the first ultrasonic echo data reflected back from the object under test include: full matrix acquisition mode, multi-element combined emission mode, and multi-angle plane wave mode.
[0053] For example, in Figure 1 In the ultrasound imaging system 100 shown, the object under test consists of a first object under test – pork belly and a second object under test – a tissue-like ultrasound membrane. The coupling medium between the ultrasound probe array and the pork belly, and between the pork belly and the tissue-like ultrasound membrane, is an ultrasound coupling agent. In the ultrasound imaging system 100, the ultrasound probe array emits and records first ultrasound emission data to the target area, and simultaneously acquires first ultrasound echo data reflected back from the object under test. The ultrasound probe array contains 64 probe elements, with a sampling rate of 40MHz, 2048 sampling points, and a sampling center frequency of 2.5MHz. The first ultrasound echo data can be described as follows (Formula 1): based on the position of each element among the 64 elements and the signals received by each element at different times.
[0054] R = R(x,t) (1)
[0055] Where R represents the echo signal field, x is the coordinate of the probe element receiving the data in the ultrasonic probe array, and t is time.
[0056] Similarly, the first ultrasonic emission data can be described as follows: Formula 2:
[0057] S=S(x,t) (2)
[0058] Where S represents the incident wave signal field, x is the coordinate of the probe element transmitting the data in the ultrasonic probe array, and t is time.
[0059] The first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area of the object under test are acquired by using an ultrasonic probe array in a full matrix acquisition mode.
[0060] For example, in the above example, the ultrasound probe array contains a total of 64 probe elements, such as... Figure 3The arrangement of the array elements involves fixing the relative position of the object under test, then exciting the nth array element to transmit the first ultrasonic transmission data into the target area, while all 64 probe elements simultaneously receive the first ultrasonic echo data; subsequently, the (n+1)th array element is excited, and this process is repeated for all array elements. The transmitted beam is a broadband beam that approximates a pulse wave. Furthermore, to improve the resolution of subsequent imaging processes, the transmitted signal can be defined as a signal that is high at the moment of excitation and low at all other times.
[0061] Step S203: Perform depth migration based on the first ultrasonic emission data and the first ultrasonic echo data to obtain the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the multiple migration depth layers. The second ultrasonic emission data and the second ultrasonic echo data corresponding to any i-th migration depth layer include the sound velocity of the ultrasonic wave in the i-th migration depth layer.
[0062] The target region is divided into several depth layers, the same number as the number of sampling points, based on a predetermined number of sampling points. A total of I migration depth layers are obtained from these depth layers. Each sampling point represents the smallest unit of depth in the target region that can be used for migration data during the migration process, based on the first ultrasonic emission data and the first ultrasonic echo data. The depth of any migration depth layer is equal to the total depth of the target region divided by the number of migration depth layers. The coordinates of any i-th migration depth layer in the target region can be the average of the depth coordinates of all depth layers contained within the i-th migration depth layer in the target region.
[0063] To obtain the echo signal field of the i-th migration depth layer in the target region, the dimensions of the first ultrasonic emission data and the first ultrasonic echo data are extended to a third dimension, where the third dimension is the depth dimension of the target region. Then, the first ultrasonic emission data and the first ultrasonic echo data are phase-shifted to obtain the second ultrasonic echo data corresponding to the i-th migration depth layer. Each i-th second ultrasonic emission data and second ultrasonic echo data includes: the wavenumber of the ultrasonic wave at the i-th migration depth layer, the depth coordinates of the i-th migration depth layer within the target region, the frequency of the ultrasonic wave at the i-th migration depth layer, and the sound velocity of the ultrasonic wave at the i-th migration depth layer.
[0064] In one possible implementation, based on the first ultrasonic emission data and the first ultrasonic echo data, as well as the depth coordinates of each of the multiple migration depth layers located in the target region, the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the multiple migration depth layers can be calculated using the acoustic wave equation; wherein the first ultrasonic emission data and the first ultrasonic echo data are regarded as the 0th migration depth layer in the target region.
[0065] In the target region with a total of i target depth layers, the position of the ultrasonic probe array can be regarded as the 0th migration depth layer. Therefore, the depth positions of the first ultrasonic emission data and the first ultrasonic echo data in the target region can be regarded as the 0th migration depth layer. Substituting the first ultrasonic emission data and the first ultrasonic echo data into the acoustic wave equation, and based on the depth coordinates of each of the multiple migration depth layers in the target region, the second ultrasonic emission data and the second ultrasonic echo data related to the sound velocity in the multiple migration depth layers can be obtained.
[0066] More specifically, the first ultrasonic emission data and the first ultrasonic echo data located in the time domain can be converted to the frequency-wavenumber domain first; then, based on the first ultrasonic emission data and the first ultrasonic echo data located in the frequency-wavenumber domain, and the depth coordinates of each of the multiple migration depth layers in the target region, the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the multiple migration depth layers can be calculated using the acoustic wave equation.
[0067] To obtain the echo signal field of the i-th migration depth layer in the target region, the dimension of the first ultrasonic echo data is extended to a third dimension, where the third dimension represents the depth dimension of the target region. Then, the first ultrasonic echo data is substituted into the acoustic wave equation, and the equation is transformed from the time domain to the frequency-wavenumber domain using data processing techniques. This yields the echo signal field in the frequency-wavenumber domain, which is related to the sound velocity at the location of the ultrasonic probe element. Subsequently, based on the echo signal field of the ultrasonic probe element and the coordinates of the i-th migration depth layer within the target region, phase shifting is used to obtain the second ultrasonic echo data corresponding to the i-th migration depth layer. Here, the sound velocity is the propagation speed of ultrasound in the i-th migration depth layer. The data processing techniques include two-dimensional Fourier transform.
[0068] For example, to obtain the echo signal field of the i-th migration depth layer in the target region, the dimension of the first ultrasonic echo data is extended to the third dimension, where the third dimension is the dimension of the depth of the target region; at this time, the position of the ultrasonic probe array is regarded as the 0th migration depth layer in the target region, and the first ultrasonic echo data can be described as follows: Formula 3:
[0069] R = R(x, z = 0, t) (3)
[0070] Where R represents the echo signal field, x is the coordinate of the probe element receiving the data in the ultrasonic probe array, t is time, and z is the depth coordinate of the i-th migration depth layer in the target region.
[0071] As in the example above Figure 1 Local magnification Figure 4 As shown, there are I migration depth layers in the target region, and the position of the ultrasound probe array is regarded as the 0th migration depth layer in the target region.
[0072] Substitute the first ultrasonic echo data into the acoustic wave equation shown in Formula 4 below:
[0073]
[0074] Where R is the echo signal field, v is the sound velocity of the ultrasound in the i-th migration depth layer, t is time, x is the coordinate of the probe element receiving the data in the ultrasound probe array, and z is the depth coordinate of the i-th migration depth layer in the target region.
[0075] Subsequently, a two-dimensional Fourier transform is performed on x and t in Equation 4 to transform the acoustic wave equation shown in Equation 4 from the time domain to the frequency-wavenumber domain, obtaining the first ultrasonic echo signal field in the frequency-wavenumber domain, as shown in Equation 5 below:
[0076]
[0077] Where R is the echo signal field; k x denoted as , where is the wavenumber of the ultrasound at the i-th migration depth layer; z is the depth coordinate of the i-th migration depth layer within the target region; w is the frequency of the ultrasound at the i-th migration depth layer; A and B are the parameters of the ascending and descending wave fields in the first ultrasound echo data, respectively; i is a complex number; v is the sound velocity of the ultrasound at the i-th migration depth layer; k z The phase shift factor in the acoustic wave equation can be expressed by the following formula 6:
[0078]
[0079] Where, k z denoted as the phase shift factor in the acoustic wave equation; w is the frequency of the ultrasonic wave at the i-th migration depth layer; v is the sound velocity of the ultrasonic wave at the i-th migration depth layer; and x is the coordinate of the probe element receiving the data in the ultrasonic probe array.
[0080] Next, for the first ultrasonic echo signal field, only the ascending wave field in the first ultrasonic echo signal field needs to be considered. Therefore, the value of parameter B in Equation 5 is assumed to be 0, thus obtaining the first ultrasonic echo signal field that is only related to the ascending wave field, which can be described as follows: Equation 7:
[0081]
[0082] Where R is the echo signal field; k x Let be the wavenumber of the ultrasound at the i-th migration depth layer; z be the depth coordinates of the i-th migration depth layer within the target region; w be the frequency of the ultrasound at the i-th migration depth layer; A be the ascending wave field in the first ultrasound echo data; i be a complex number; v be the sound velocity of the ultrasound at the i-th migration depth layer; k be the wavenumber of the ultrasound at the i-th migration depth layer; ? zis the phase shift factor in the acoustic wave equation.
[0083] Finally, the probe elements of the ultrasound probe array are located in the 0th layer of the target region, and the value of z in Formula 7 is 0. Therefore, the i-th second ultrasound echo data corresponding to the i-th layer can be described as follows: Formula 8:
[0084]
[0085] Where R is the echo signal field; k x denoted by , where is the wavenumber of the echo from the i-th migration depth layer; z is the depth coordinate of the i-th migration depth layer within the target region; w is the frequency of the ultrasonic wave from the i-th migration depth layer; i is a complex number, and "-" indicates that the direction of the echo signal field is the first direction, i.e., along the direction in which the value of i increases; v is the speed of sound of the ultrasonic wave from the i-th migration depth layer; k z is the phase shift factor in the acoustic wave equation.
[0086] Similarly, based on the first ultrasonic emission data, the i-th second ultrasonic emission data corresponding to the i-th layer is obtained through phase shifting. The i-th second ultrasonic emission data can be described as follows: Formula 9:
[0087]
[0088] Where S is the incident wave signal field; k x Let be the wave number of the ultrasound in the i-th migration depth layer; z be the depth coordinates of the i-th migration depth layer within the target region; w be the frequency of the ultrasound in the i-th migration depth layer; i is a complex number, and "+" indicates that the direction of the incident wave signal field is a second direction opposite to the first direction, i.e., along the direction in which the value of z decreases; v be the sound velocity of the ultrasound in the i-th migration depth layer; k z is the phase shift factor in the acoustic wave equation.
[0089] Step S205: Calculate the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0090] The response matrix corresponding to any i-th depth migration layer includes: the sound velocity of the ultrasound at the i-th migration depth layer, the coordinates of the probe element receiving data within the ultrasound probe array, the coordinates of the probe element transmitting data within the ultrasound probe array, and the depth coordinates of the i-th migration depth layer within the target region; it reflects the cross-correlation characteristics between the second ultrasound echo data and the second ultrasound echo data in the i-th layer. Furthermore, the response matrix corresponding to any i-th depth migration layer is a square matrix, and the combination of elements on the diagonal of the response matrix can be used to represent the signal energy intensity of the acoustic signal field in the i-th layer.
[0091] In one possible implementation, the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer is calculated; the tensor product is summed according to the frequencies of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer to obtain the response matrix corresponding to the i-th migration depth layer.
[0092] More specifically, the second ultrasonic echo data and the second ultrasonic emission data corresponding to the i-th migration depth layer can be converted to the frequency domain;
[0093] Based on the second ultrasonic echo data and the second ultrasonic emission data located in the frequency domain corresponding to the i-th migration depth layer, calculate the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0094] For example, the second ultrasonic echo data and the second ultrasonic transmission data of the i-th time are transformed into the frequency domain by inverse Fourier transform, and the tensor product of the corresponding second ultrasonic echo data and the second ultrasonic transmission data is calculated. Then, the tensor product is summed according to the frequency of the second ultrasonic echo data and the second ultrasonic transmission data to obtain the response matrix corresponding to the i-th depth migration layer.
[0095] For example, the response matrix corresponding to the i-th deep migration layer is calculated according to the following formula 10.
[0096]
[0097] M is the response matrix corresponding to the i-th migration depth layer; R is the echo signal field; S is the incident wave signal field; x1 is the coordinate of the probe element receiving data in the ultrasonic probe array; x2 is the coordinate of the probe element transmitting data in the ultrasonic probe array; z is the depth coordinate of the i-th migration depth layer in the target region; v is the sound velocity of the ultrasonic wave in the i-th migration depth layer; w is the frequency of the ultrasonic wave in the i-th migration depth layer.
[0098] Step S207: Based on the predetermined sound speed range, with the minimum half-width at half-maximum of the signal intensity on the sub-diagonal of the response matrix corresponding to the i-th deep migration layer as the convergence target, optimize the sound speed of the response matrix corresponding to the i-th deep migration layer to obtain the optimized sound speed corresponding to the i-th migration depth layer.
[0099] In the response matrix corresponding to the i-th depth migration layer, different sound velocities affect the diagonal broadening of the response matrix, and consequently, the signal intensity of the corresponding ultrasound waves. The smaller the diagonal broadening of the response matrix, the more convergent the diagonal, and the stronger the corresponding ultrasound signal intensity. Furthermore, the elements on the diagonal of the response matrix with the most convergent diagonal produce the clearest imaging effect. The degree of convergence of the response matrix's diagonal can be evaluated using the full width at half maximum (FWHM) of the signal intensity on the secondary diagonal.
[0100] For example, the diagram showing the change in the diagonal width of the response matrix at three different sound speeds is as follows: (The diagram is incomplete and requires further context to be fully translated.) Figure 5 As shown, the first sound velocity B is the optimization sound velocity corresponding to the i-th depth migration layer, and the diagonal line width of the response matrix corresponding to the first sound velocity B is the shortest.
[0101] For example, in the sound velocity optimization process described above, the predetermined sound velocity is between 1400 m / s and 1500 m / s, and the optimization accuracy is 1 m / s. Using a traversal method, the sound velocity is evaluated, and the resulting optimized sound velocity profile is shown below. Figure 6 As shown.
[0102] In one possible implementation, the sound velocity of the response matrix corresponding to the i-th deep migration layer is optimized using a bisection method or the golden section method.
[0103] The binary search method can be used to find a specific element in an ordered list (such as searching for the optimal sound velocity in a response matrix). It divides the list into two halves, takes the median value of the sound velocity and compares it with the assumed target value of the sound velocity. Then, based on the comparison result, it decides to continue searching in one half of the list. This process is repeated until the optimal sound velocity value is found.
[0104] The golden section method, also known as the 0.618 method, is an optimization method that explores the values of the half-width and height of the secondary diagonal elements of the response matrix to continuously narrow the search interval containing the minimum sound speed, and finally obtains the optimal sound speed.
[0105] Step S209: Based on the optimized sound velocity and response matrix corresponding to multiple migration depth layers, obtain the imaging result of the i-th migration depth layer, and obtain the target imaging result based on the imaging results corresponding to each of the i migration depth layers.
[0106] The main diagonal elements of the response matrix corresponding to the i-th migration depth layer include the coordinates x1 of the probe element receiving data in the ultrasonic probe array, the coordinates x2 of the probe element transmitting data in the ultrasonic probe array, the depth coordinate z of the i-th migration depth layer in the target region, and the sound velocity v of the ultrasonic wave in the i-th migration depth layer; wherein, on the main diagonal, the values of x1 and x2 of a single element are equal.
[0107] Based on the optimization velocity corresponding to the i-th migration depth layer, the coordinates of the probe element receiving data in the ultrasonic probe array in the main diagonal elements of the response matrix corresponding to the i-th migration depth layer, and the ultrasonic signal intensity in the i-th migration depth layer, the imaging result of the i-th migration depth layer is calculated. The imaging result of the i-th migration depth layer is one-dimensional, including the coordinates of the probe element receiving data in the ultrasonic probe array and the ultrasonic signal intensity. Based on the imaging results of multiple migration depth layers and the depth coordinates of each migration depth layer in the target area, the multiple one-dimensional imaging results are stitched together according to the coordinates of the probe element receiving data in the ultrasonic probe array to obtain the target imaging result. The target imaging result is two-dimensional, including: the coordinates of the probe element receiving data in the ultrasonic probe array, the ultrasonic signal intensity, and the depth coordinates of multiple migration depth layers in the target area.
[0108] For example Figure 7 As shown in (a), 400 migration depth layers were obtained from a total of 2048 sampling points in the target area. Based on the 400 imaging results corresponding to each of these 400 migration depth layers, the imaging result corresponding to the target area was obtained. Figure 7 (b) is the imaging result obtained using the 1540 m / s uniform sound speed model. Figure 7 (c) and Figure 7 (d) are respectively Figure 7 Partial magnification of the scattering points in the imaging results in (a) and (b). It can be seen that the ultrasound imaging method proposed in this application effectively reduces side lobes and artifacts in the imaging results.
[0109] Corresponding to the method provided in this application, this application also provides an ultrasound imaging device 300. For example... Figure 8 As shown, the ultrasound imaging device 300 includes: a data acquisition unit 301, a data migration unit 303, a data calculation unit 305, a data optimization unit 307, and an ultrasound imaging unit 309.
[0110] The data acquisition unit 301 is used to acquire the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test through the ultrasonic probe array.
[0111] The data migration unit 303 is used to perform depth migration based on the first ultrasonic emission data and the first ultrasonic echo data to obtain the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the multiple migration depth layers; the second ultrasonic emission data and the second ultrasonic echo data corresponding to any i-th migration depth layer include the sound velocity of the ultrasonic wave in the i-th migration depth layer.
[0112] The data calculation unit 305 is used to calculate the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
[0113] The data optimization unit 307 is used to optimize the sound velocity of the response matrix corresponding to the i-th deep migration layer based on a predetermined sound velocity range and with the minimum half-width of the signal intensity on the sub-diagonal of the response matrix corresponding to the i-th deep migration layer as the convergence target, so as to obtain the optimized sound velocity corresponding to the i-th migration depth layer.
[0114] The ultrasound imaging unit 309 is used to obtain the imaging result of the i-th migration depth layer based on the optimization sound velocity corresponding to the i-th migration depth layer and the response matrix corresponding to the i-th migration depth layer, and to obtain the target imaging result based on the imaging results corresponding to multiple migration depth layers.
[0115] According to another embodiment, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed in a computing device, causes the computing device to perform the ultrasound imaging method provided in any embodiment of this specification.
[0116] According to another embodiment, a computing device is also provided, including a memory and a processor, wherein executable code is stored in the memory, and when the processor executes the executable code, it implements the ultrasound imaging method provided in any embodiment of this specification.
[0117] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this invention can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium.
[0118] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.
Claims
1. An ultrasound imaging method, characterized in that, include: The first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test are obtained by an ultrasonic probe array. Based on the first ultrasonic emission data and the first ultrasonic echo data, depth migration is performed to obtain the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the multiple migration depth layers. The second ultrasonic emission data and the second ultrasonic echo data corresponding to any i-th migration depth layer include the sound velocity of the ultrasonic wave in the i-th migration depth layer. Calculate the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer; Based on a predetermined range of sound speeds, the minimum half-width of the signal intensity on the sub-diagonal of the response matrix corresponding to the i-th deep migration layer is used as the convergence target to optimize the sound speed of the response matrix corresponding to the i-th deep migration layer, thereby obtaining the optimized sound speed corresponding to the i-th migration depth layer. Based on the optimization velocity of the i-th migration depth layer and the response matrix of the i-th migration depth layer, the imaging result of the i-th migration depth layer is obtained, and the target imaging result is obtained based on the imaging results of each of the multiple migration depth layers.
2. The ultrasound imaging method according to claim 1, wherein, The acquisition of the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test through an ultrasonic probe array includes: The ultrasonic probe array is used to acquire the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area of the object under test in a full matrix acquisition mode.
3. The ultrasound imaging method according to claim 1, wherein, The step of performing depth migration based on the first ultrasonic emission data and the first ultrasonic echo data to obtain second ultrasonic emission data and second ultrasonic echo data corresponding to multiple migration depth layers includes: Based on the first ultrasonic emission data and the first ultrasonic echo data, and the depth coordinates of each of the plurality of migration depth layers in the target region, the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the plurality of migration depth layers are calculated using the acoustic wave equation; wherein the first ultrasonic emission data and the first ultrasonic echo data are regarded as the 0th migration depth layer in the target region.
4. The ultrasound imaging method according to claim 3, wherein, The step of calculating the second ultrasonic emission data and second ultrasonic echo data corresponding to each of the plurality of migration depth layers in the target region based on the first ultrasonic emission data and the first ultrasonic echo data, and the depth coordinates of each of the plurality of migration depth layers in the target region, using the acoustic wave equation, includes: The first ultrasonic transmission data and the first ultrasonic echo data located in the time domain are converted to the frequency-wavenumber domain. Based on the first ultrasonic emission data and the first ultrasonic echo data located in the frequency-wavenumber domain, and the depth coordinates of each of the plurality of migration depth layers in the target region, the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the plurality of migration depth layers are calculated using the acoustic wave equation.
5. The ultrasound imaging method according to claim 1, wherein, The step of calculating the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer includes: Calculate the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer; The response matrix corresponding to the i-th migration depth layer is obtained by summing the tensor products of the frequencies of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
6. The ultrasound imaging method according to claim 5, wherein, The calculation of the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer includes: The second ultrasonic echo data and the second ultrasonic emission data corresponding to the i-th migration depth layer are converted to the frequency domain; Based on the second ultrasonic echo data and the second ultrasonic emission data located in the frequency domain corresponding to the i-th migration depth layer, calculate the tensor product of the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer.
7. The ultrasound imaging method according to any one of claims 1-6, wherein, The optimization of the sound velocity of the response matrix corresponding to the i-th deep migration layer includes: optimizing the sound velocity of the response matrix corresponding to the i-th deep migration layer using a bisection method or a golden section method.
8. An ultrasonic imaging device, characterized in that, include: The data acquisition unit is used to acquire the first ultrasonic emission data and the first ultrasonic echo data corresponding to the target area in the object under test through the ultrasonic probe array; The data migration unit is used to perform depth migration based on the first ultrasonic emission data and the first ultrasonic echo data to obtain the second ultrasonic emission data and the second ultrasonic echo data corresponding to each of the multiple migration depth layers. The second ultrasonic emission data and the second ultrasonic echo data corresponding to any i-th migration depth layer include the sound velocity of the ultrasonic wave in the i-th migration depth layer. The data calculation unit is used to calculate the response matrix corresponding to the i-th migration depth layer based on the second ultrasonic emission data and the second ultrasonic echo data corresponding to the i-th migration depth layer. The data optimization unit is used to optimize the sound velocity of the response matrix corresponding to the i-th deep migration layer based on a predetermined sound velocity range and with the minimum half-width of the signal intensity on the sub-diagonal of the response matrix corresponding to the i-th deep migration layer as the convergence target, so as to obtain the optimized sound velocity corresponding to the i-th migration depth layer. An ultrasound imaging unit is used to obtain the imaging result of the i-th migration depth layer based on the optimization sound velocity corresponding to the i-th migration depth layer and the response matrix corresponding to the i-th migration depth layer, and to obtain the target imaging result based on the imaging results corresponding to each of the multiple migration depth layers.
9. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed in a computing device, the computing device performs the method of any one of claims 1-6.
10. A computing device comprising a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program, implements the method of any one of claims 1-6.