A method for intervening in the elimination of reverberation artifacts in ultrasound images

Abstract

The application relates to the technical field of image processing, and discloses a method for eliminating reverberation artifacts in interventional ultrasound images, which comprises the following steps: calculating the spatial partial derivative of an initial tissue acoustic impedance distribution matrix to obtain an acoustic impedance gradient tensor matrix; combining the instrument coating reference acoustic impedance and the spatial resolution to calculate an attenuation compensation factor matrix; using the attenuation compensation factor matrix to operate on an original ultrasound radio frequency echo envelope matrix to calculate a local acoustic phase shift matrix; combining the velocity field and the scanning line time interval to calculate a motion distortion flow field vector matrix; according to the motion distortion flow field vector matrix, inversely resampling the original matrix to construct a spatially realigned ultrasound matrix; based on the acoustoelectric conversion coefficient, calculating a reverberation artifact energy distribution matrix; introducing a thermal noise base extreme value to calculate a nonlinear projection convergence factor, and obtaining a projection energy matrix by constraint; and finally inversely solving the artifact voltage matrix and deducting the artifact voltage matrix from the original image to generate a target ultrasound image matrix without artifacts.

Description

Technical Field

[0001] This invention relates to the field of image processing technology, specifically to a method for eliminating reverberation artifacts in interventional ultrasound images. Background Technology

[0002] In minimally invasive interventional surgery, ultrasound-guided technology is widely used due to its real-time capability. During surgery, surgeons often need to insert metal interventional instruments into human tissue. When ultrasound waves irradiate the metal instruments, due to differences in acoustic impedance, the sound waves undergo multiple reflections between the instrument and the tissue, resulting in reverberation artifacts on the image. Reverberation artifacts can severely obscure the true anatomical structures behind the instruments, increasing the risks of diagnosis and surgery. To eliminate reverberation artifacts, existing technologies mostly employ pixel-level smoothing filtering methods. These conventional filtering methods primarily process pixels in the spatial or frequency domains. However, in suppressing artifacts, conventional filtering methods often fail to effectively distinguish between artifact features and true physical boundaries. This approach leads to blurring of the fine structures at the tips of highly dynamic instruments, significantly reducing image resolution and guidance accuracy. Furthermore, modern interventional instruments often have special ultrasound-enhancing coatings on their surfaces. These coatings produce nonlinear acoustic attenuation. Existing elimination algorithms do not consider this underlying physical characteristic. During feature extraction, the nonlinear acoustic attenuation of the instrument coating generates severe artifact gradients. The system is highly susceptible to misinterpreting these artifact gradients as true tissue boundaries or reverberation artifacts, thus introducing computational errors. Meanwhile, existing processing methods often treat ultrasound images as absolutely static sections. In actual ultrasound scanning, there is an inherent time difference between the emission of adjacent scan lines. During interventional procedures, the time difference between scan lines within a frame is superimposed on the instantaneous spatial motion of the instrument, leading to severe spatiotemporal misalignment distortion. Existing methods lack a reverse compensation mechanism for such distortions, causing the extracted artifact features to be severely offset in both time and spatial coordinates. Finally, in performing the final artifact removal step, existing techniques often use direct subtraction of grayscale or voltage signals. This operation ignores the physical laws of sound field energy. At the boundary between real tissue and reverberation artifacts, there is a drastic change in energy distribution. If artifacts are eliminated by direct subtraction after spatiotemporal correction, the energy abrupt change at the tissue-artifact boundary will cause "ghosting" and negative energy leakage problems, thus generating a negative energy "black hole" on the image that does not conform to objective physical laws.

[0003] In summary, there is a need for a method to eliminate reverberation artifacts in interventional ultrasound images, which can penetrate deep into the physical acoustic layer to remove artifacts and effectively overcome defects such as instrument tip blurring, coating artifact gradient, spatiotemporal misalignment distortion, and energy ghosting leakage at the interface. Summary of the Invention

[0004] This invention provides a method for eliminating reverberation artifacts in interventional ultrasound images, thereby helping to solve the problems mentioned in the background section.

[0005] This invention provides the following technical solution: a method for eliminating reverberation artifacts in interventional ultrasound images, comprising: Calculate the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and obtain the acoustic impedance gradient tensor matrix. Based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image, the attenuation compensation factor matrix is ​​calculated by performing an exponential operation on the acoustic impedance gradient tensor matrix. By combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude, an arcsine operation is performed on the attenuation compensation factor matrix to calculate the local acoustic phase shift matrix. Based on the instantaneous spatial velocity field and the emission time interval of adjacent scan lines, and combined with the local acoustic phase shift matrix, the horizontal and vertical motion distortion flow field vector matrices are calculated respectively. The original ultrasonic radio frequency echo envelope matrix is ​​resampled by inverse coordinate offset using the motion distortion flow field vector matrix, and a cosine weight of the local acoustic phase offset matrix is ​​applied to construct a spatially realigned ultrasonic matrix. Based on the acoustic-electric conversion coefficient and the duration of the ultrasonic pulse, the reverberation artifact energy distribution matrix is ​​calculated according to the difference between the original ultrasonic radio frequency echo envelope matrix and the spatially realigned ultrasonic matrix. Based on the system's absolute temperature, sound wave center wavelength, and total emitted transient sound intensity energy, calculate the thermal noise floor extremum and nonlinear projection convergence factor, constrain the reverberation artifact energy distribution matrix, and calculate the projection energy matrix. The inverse square root of the projected energy matrix is ​​used to calculate the reverberation artifact voltage matrix, which is then subtracted from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix.

[0006] Optionally, the calculation of the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and the determination of the acoustic impedance gradient tensor matrix, includes: Obtain the initial tissue acoustic impedance distribution matrix of the current detection area; Calculate the first-order spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, respectively; Add the square of the first spatial partial derivative in the horizontal direction to the square of the first spatial partial derivative in the vertical direction; The square root of the sum is taken to obtain the acoustic impedance gradient tensor matrix.

[0007] Optionally, the step of performing an exponential operation on the acoustic impedance gradient tensor matrix based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image to calculate the attenuation compensation factor matrix includes: Obtain the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image; The first product is obtained by multiplying the acoustic impedance gradient tensor matrix by the spatial physical resolution of the ultrasound image; The quotient is obtained by dividing the first product by the reference acoustic impedance of the interventional device coating. Take the negative of the quotient as the exponent, and perform exponential operation with the natural constant as the base to obtain the attenuation compensation factor matrix.

[0008] Optionally, the step of combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude to perform an arcsine operation on the attenuation compensation factor matrix and calculate the local acoustic phase shift matrix includes: Obtain the original ultrasonic radio frequency echo envelope matrix of the current frame, and extract the global maximum voltage amplitude from the original ultrasonic radio frequency echo envelope matrix; The second product is obtained by multiplying the original ultrasonic radio frequency echo envelope matrix with the attenuation compensation factor matrix; Divide the second product by the global maximum voltage amplitude to obtain the ratio; Perform an arcsine operation on the ratio to obtain the local acoustic phase shift matrix.

[0009] Optionally, the step of calculating the horizontal and vertical motion distortion flow field vector matrices based on the instantaneous spatial velocity field and the emission time interval between adjacent scan lines, combined with the local acoustic phase shift matrix, includes: Acquire the instantaneous horizontal and vertical velocity fields of the interventional device in the current frame, and acquire the emission time interval between adjacent scan lines; Multiplying the instantaneous horizontal velocity field, the emission time interval between adjacent scan lines, and the local acoustic phase offset matrix yields the horizontal motion distortion flow field vector matrix. Multiplying the instantaneous vertical velocity field, the emission time interval between adjacent scan lines, and the local acoustic phase offset matrix yields the vertical motion distortion flow field vector matrix.

[0010] Optionally, the step of using the motion-distorted flow field vector matrix to perform inverse coordinate offset resampling on the original ultrasonic radio frequency echo envelope matrix and applying cosine weights of the local acoustic phase offset matrix to construct a spatially realigned ultrasonic matrix includes: The coordinate offset is determined based on the horizontal motion distortion flow field vector matrix and the vertical motion distortion flow field vector matrix; The original ultrasonic radio frequency echo envelope matrix is ​​resampled by bilinear interpolation using the coordinate offset to obtain a resampled ultrasonic matrix. The cosine value of the local acoustic phase offset matrix is ​​calculated to obtain the cosine weight matrix; Multiplying the resampled ultrasound matrix by the cosine weight matrix yields the spatially realigned ultrasound matrix.

[0011] Optionally, the step of calculating the reverberation artifact energy distribution matrix based on the acoustic-to-electrical conversion coefficient and the ultrasonic pulse duration, according to the difference between the original ultrasonic radio frequency echo envelope matrix and the spatially realigned ultrasonic matrix, includes: Obtain the acoustic-to-electric conversion coefficient and the duration of the ultrasonic pulse; The difference matrix is ​​obtained by subtracting the original ultrasound radio frequency echo envelope matrix from the spatially realigned ultrasound matrix. The sound pressure matrix is ​​obtained by multiplying the sound-to-electric conversion coefficients by the difference matrix; Calculate the square of the sound pressure matrix; The numerator is obtained by multiplying the squared value by the duration of the ultrasonic pulse; The denominator term is obtained by multiplying the reference acoustic impedance of the interventional device coating by a constant two. Dividing the numerator by the denominator yields the reverberation artifact energy distribution matrix.

[0012] Optionally, the step of calculating the thermal noise floor extremum and nonlinear projection convergence factor, constraining the reverberation artifact energy distribution matrix, and calculating the projection energy matrix based on the system absolute temperature, sound wave center wavelength, and total emitted transient sound intensity energy includes: To obtain the normal absolute temperature of the human body, the center wavelength of the sound wave, and the total transient sound intensity energy emitted by the system; Multiplying the Boltzmann constant by the stated normal absolute temperature of the human body yields the product term; Dividing the product term by the square of the center wavelength of the sound wave yields the thermal noise floor extreme value; The energy sum is obtained by adding the reverberation artifact energy distribution matrix to the thermal noise floor extremum. Divide the total transient acoustic intensity energy emitted by the system by the sum of the energy values ​​and take the negative number as the projection exponent; The exponent is obtained by performing an exponential operation on the projected exponent with the natural constant as the base. Subtracting the exponent from the constant one yields the energy conservation projection factor matrix. Multiplying the reverberation artifact energy distribution matrix with the energy conservation projection factor matrix yields the projected energy matrix.

[0013] Optionally, the step of performing inverse square root extraction on the projected energy matrix to calculate the reverberation artifact voltage matrix, and subtracting it from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix includes: Multiply the constant 2, the reference acoustic impedance of the interventional device coating, and the projection energy matrix to obtain the divisor; The quotient is obtained by dividing the dividend by the duration of the ultrasonic pulse. The square root of the quotient term is taken to obtain the root matrix; the root matrix is ​​divided by the acoustic-electric conversion coefficient to obtain the reverberation artifact voltage matrix. The target ultrasound image matrix is ​​generated by subtracting the reverberation artifact voltage matrix from the original ultrasound radio frequency echo envelope matrix.

[0014] The present invention has the following beneficial effects: 1. By performing in-depth calculations and mapping of the underlying physical acoustic data of ultrasound, this technical solution removes and eliminates reverberation artifacts in ultrasound images of minimally invasive interventional surgeries. In the specific environment of minimally invasive interventional surgery, doctors often need to insert metal interventional instruments into human tissue. When ultrasound waves irradiate the metal instruments, due to the difference in acoustic impedance, the sound waves will reflect back and forth multiple times between the instruments and the tissue, thus forming reverberation artifacts on the screen that severely obscure the real organ structures behind the instruments. The reason for designing this new solution is that most traditional artifact removal methods use pixel-level smoothing filtering. This approach cannot effectively distinguish between false artifacts and real physical boundaries when eliminating artifacts, and it is easy to obscure the fine structure of the high-dynamic instrument tip that doctors need to see most clearly during surgery, thus greatly reducing image resolution and puncture guidance accuracy. Furthermore, modern interventional instruments typically have a special ultrasound-enhancing coating. This coating generates nonlinear acoustic attenuation, creating artifact gradients that mislead existing algorithms. In addition, the time difference in ultrasound probe scanning means that if the surgical instrument moves during this period, the captured artifact position will suffer severe spatiotemporal misalignment distortion. Simply subtracting grayscale or voltage signals to eliminate artifacts can cause energy leakage at the boundary between real tissue and artifacts, producing ghosting and negative energy "black holes" that do not conform to objective physical laws. To address these practical problems, this solution delves into the underlying physical acoustics, calculating acoustic impedance gradients, shielding coating interference, and inversely compensating for motion misalignment, while precisely subtracting artifact voltage under strict energy conservation constraints. In this specific medical operating environment, the unique benefits of this solution are: it completely breaks through the limitations of traditional image processing, cleanly removing reverberation artifacts from the image, effectively overcoming the fatal flaw of blurring at the instrument tip, and perfectly preserving the high resolution of the image. It not only intelligently eliminates positional deviations caused by coating interference and spatiotemporal misalignment, but also eliminates the problem of energy ghosting and leakage at the interface from a physical perspective, ultimately generating an extremely clear, realistic, and distortion-free target ultrasound image for doctors, significantly reducing the risks of diagnosis and surgery.

[0015] 2. By obtaining the initial tissue acoustic impedance distribution matrix of the current detection area, the first-order spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions are calculated respectively. The squares of the first-order spatial partial derivatives in the horizontal and vertical directions are added together, and the square root of the sum is further performed to obtain the final acoustic impedance gradient tensor matrix. This method abandons the superficial processing of traditional conventional artifact removal methods that only smooth the pixel grayscale. It directly delves into the physical layer of ultrasound imaging to highlight the physical boundaries of the structure in the image. It can use the degree of change of the real physical quantity acoustic impedance as an objective basis to distinguish reverberation artifacts from real strong reflection interfaces. It effectively avoids the serious defect of conventional filtering processing in suppressing reverberation artifacts, which cannot accurately identify features and causes blurring of the fine structure of high dynamic instrument tips. While preserving the boundary information of real anatomical structures, it lays an extremely accurate physical morphological foundation for subsequent artifact removal, greatly improving the accuracy of low-level feature extraction and the resolution of medical diagnostic images.

[0016] 3. By obtaining the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image, the acoustic impedance gradient tensor matrix calculated in the previous step is multiplied by the spatial physical resolution of the ultrasound image to obtain the first product. The first product is then divided by the reference acoustic impedance of the interventional device coating to obtain the corresponding quotient. The negative number of the quotient is then extracted as the exponent, and exponential operation is performed with the natural constant as the base to finally construct the attenuation compensation factor matrix. This fully and specifically considers the underlying physical characteristic that modern interventional devices are usually coated with special ultrasound-enhancing coatings. The exponential attenuation compensation factor constructed using the intrinsic acoustic impedance and spatial resolution of the coating acts as an intelligent filter to intercept and suppress the artifact gradient caused by the nonlinear acoustic attenuation phenomenon of the coating. It can accurately identify and forcibly suppress the false artifact gradient caused by the nonlinear acoustic attenuation phenomenon of the coating, and nonlinearly compress the calculated values ​​of these artifact gradient regions and force them to approach zero. This effectively prevents the system from misjudging the artifact gradient caused by the nonlinear acoustic attenuation of the device coating as the real tissue boundary or reverberation artifact, and greatly improves the robustness and anti-interference suppression capability of subsequent artifact feature identification.

[0017] 4. By acquiring the original ultrasonic radio frequency echo envelope matrix of the current frame and accurately extracting the global maximum voltage amplitude from the matrix, the original ultrasonic radio frequency echo envelope matrix is ​​multiplied by the previously constructed attenuation compensation factor matrix to obtain a second product. Then, the second product is divided by the global maximum voltage amplitude to obtain a normalized ratio. Finally, an arcsine operation is performed on the ratio to calculate the local acoustic phase shift matrix. This achieves the accurate mapping of the chaotic voltage amplitude signal on the surface into the acoustic phase distortion characteristics of the underlying layer. It cleverly combines the compensation factor that filters out coating interference to recalibrate the detection signal. This not only objectively quantifies the severity of the physical phase shift caused by multiple reflections and reverberation of the sound wave in the original ultrasonic signal, but also significantly amplifies the distortion and twisting details of the artifact region by utilizing the nonlinear stretching characteristics of the arcsine function. This provides a direct mathematical direction and physical judgment basis for the subsequent accurate spatial positioning and independent separation and extraction of free artifact components, overcoming the technical bottleneck of relying solely on voltage amplitude for threshold segmentation, which is prone to interference and misjudgment.

[0018] 5. By acquiring the instantaneous horizontal and vertical velocity fields of the interventional device in the current frame, as well as the emission time interval of adjacent scan lines, the instantaneous horizontal velocity field is multiplied together with the emission time interval of adjacent scan lines and the local acoustic phase shift matrix obtained in the previous step to obtain the horizontal motion distortion flow field vector matrix. Simultaneously, the instantaneous vertical velocity field is multiplied together with the emission time interval of adjacent scan lines and the local acoustic phase shift matrix to obtain the vertical motion distortion flow field vector matrix. This fully considers and deeply quantifies the physical deformation law of ultrasound images in dynamic continuous scanning sequence, breaking the limitation of existing processing schemes that usually treat ultrasound images as an absolutely static section for isolated calculation. A special mathematical model was developed for the image position offset caused by the superposition of intra-frame scan line emission time difference and instantaneous spatial motion of medical devices during interventional operations. The actual horizontal and vertical deviation distances of each physical point in the image due to the scanning time difference and physical motion of the device were accurately calculated, providing indispensable dynamic reverse flow field parameter support for completely solving the serious spatiotemporal misalignment distortion problem.

[0019] 6. By jointly determining the spatial coordinate offset of the pixel point based on the horizontal motion distortion flow field vector matrix and the vertical motion distortion flow field vector matrix obtained in the previous step, the original ultrasonic radio frequency echo envelope matrix is ​​subjected to bilinear interpolation resampling operation to obtain the resampled ultrasonic matrix. The cosine value of the local acoustic phase offset matrix is ​​calculated to obtain the corresponding cosine weight matrix. Finally, the resampled ultrasonic matrix is ​​multiplied with the cosine weight matrix to construct the spatial realigned ultrasonic matrix. A reverse spatiotemporal compensation correction mechanism for the micro time difference of ultrasonic dynamic scanning is established. The motion distortion flow field parameters are used to reverse and forcibly pull the physical coordinates of the original image that have been misaligned back to the absolutely correct position, just like time rewind. The cosine weight reflecting the phase dynamic deformation is innovatively applied to effectively correct the physical reception intensity of the underlying signal. The spatial and temporal distortion caused by the superposition of scanning time difference by the small movement of the instrument is completely eliminated. The real reverberation artifact structure features hidden in the cluttered ultrasonic background are aligned to a unified time reference measurement plane with extremely high precision, and the real spatial position and shape of the reverberation artifact are exposed with extremely high precision.

[0020] 7. By obtaining the underlying acoustic-to-electrical conversion coefficients and the duration of the ultrasonic pulse, the original ultrasonic radio frequency echo envelope matrix is ​​subtracted from the previously constructed spatially realigned ultrasonic matrix to obtain the difference matrix. The acoustic-to-electrical conversion coefficients are multiplied by this difference matrix to obtain the sound pressure matrix, and its square is calculated. This squared value is then multiplied by the ultrasonic pulse duration as the numerator, while the reference acoustic impedance of the interventional device coating is multiplied by a constant two as the denominator. Finally, the numerator is divided by the denominator to calculate the reverberation artifact energy distribution matrix. This method strictly follows the law of conservation of work of dynamic physical energy in the objective sound field, completely eliminating the need for... Existing image processing technologies suffer from arithmetic logic errors and energy information distortion caused by directly using grayscale or voltage signals for subtraction. By rigorously comparing the original signal image with the realigned image, the abnormal components of free reverberation artifacts were successfully separated and extracted. Furthermore, a rigorous underlying physical conversion logic was used to transform the differences in surface electrical signals into the actual physical quantity of acoustic work done, namely absolute energy density. This method precisely quantifies the absolute physical energy contained in the reverberation artifacts that urgently need to be completely eliminated, establishing an extremely reliable and scientifically sound energy domain calibration benchmark for subsequent safe energy deduction calculations.

[0021] 8. By obtaining the normal absolute temperature of the human body, the center wavelength of the sound wave, and the total emitted transient sound intensity energy of the system, the product of the Boltzmann constant and the normal absolute temperature of the human body is divided by the square of the center wavelength of the sound wave to obtain the extreme value of the thermal noise floor. The reverberation artifact energy distribution matrix is ​​then added to this extreme value of the thermal noise floor as the energy sum. Subsequently, the total emitted transient sound intensity energy of the system is divided by this energy sum, and its negative value is used as the projection exponent for exponential calculation of the natural constant base. The result is subtracted from the constant to obtain the energy conservation projection factor matrix, which is then multiplied by the reverberation artifact energy distribution matrix to obtain the projected energy matrix. This interdisciplinary approach introduces... The underlying limit parameters in statistical thermodynamics physics have successfully constructed a safety threshold valve to prevent the complete collapse of image energy. The mathematical and physical bottom limit value is cleverly set to avoid the collapse of the division arithmetic singularity. It effectively ensures that the reverberation artifact energy can be subject to extremely smooth nonlinear convergence constraint as it approaches the physical threshold of the transient sound intensity energy of the total emission of the system. This fundamentally prevents the serious phenomenon of excessive energy deduction and illegal leakage when stripping artifacts. It completely solves the malignant calculation defects of traditional algorithms that easily lead to severe ghosting and negative energy black holes at the abrupt change at the boundary between real tissue and artifact, which violate the laws of physics.

[0022] 9. By multiplying the constant 2 with the reference acoustic impedance of the interventional device coating and the projected energy matrix that has passed the safety limit review in the previous steps to obtain the dividend, and then dividing the dividend by the ultrasound pulse duration to obtain the quotient, the square root of the quotient is obtained. This quotient is then divided by the acoustic-electric conversion coefficient to inversely and losslessly reconstruct the reverberation artifact voltage matrix. Finally, the original ultrasound radio frequency echo envelope matrix is ​​subtracted from this extremely accurately calculated reverberation artifact voltage matrix to generate the target ultrasound image matrix. This establishes and completes an extremely rigorous cross-domain inverse mapping closed loop from the energy physics domain to the underlying voltage domain. By changing the computing mechanism, the projected energy, which is strictly controlled and absolutely conforms to the physical constraints of dynamic energy conservation, is retranslated and reversed into a real electrical signal in the voltage dimension that can be directly understood and processed by the underlying ultrasound hardware receiving device. Then, in the most original broadband signal matrix, the final precise physical magnitude subtraction and blanking operation is safely and smoothly performed. Like peeling an onion, it thoroughly and precisely peels away and completely eliminates false reverberation interference components from the complex and ever-changing background reflected ultrasound signal of biological tissue. Finally, it outputs high-quality real-time images for minimally invasive interventional medical diagnosis that are not only completely free of severe reverberation artifacts but also have absolutely clear and faithful underlying anatomical structures. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the basic process of the present invention.

[0024] Figure 2 This is a flowchart of the acoustic impedance gradient extraction and coating attenuation compensation calculation of the present invention.

[0025] Figure 3 This is a flowchart of the reverse realignment process for acoustic phase distortion and spatiotemporal misalignment in this invention.

[0026] Figure 4 This is a flowchart of the reverse solution of energy projection constraint and physical voltage in this invention. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1, refer to Figure 1 A method for eliminating reverberation artifacts in interventional ultrasound images, comprising: Calculate the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and obtain the acoustic impedance gradient tensor matrix. Based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image, the attenuation compensation factor matrix is ​​calculated by performing an exponential operation on the acoustic impedance gradient tensor matrix. By combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude, an arcsine operation is performed on the attenuation compensation factor matrix to calculate the local acoustic phase shift matrix. Based on the instantaneous spatial velocity field and the emission time interval of adjacent scan lines, and combined with the local acoustic phase shift matrix, the horizontal and vertical motion distortion flow field vector matrices are calculated respectively. The original ultrasonic radio frequency echo envelope matrix is ​​resampled by inverse coordinate offset using the motion distortion flow field vector matrix, and a cosine weight of the local acoustic phase offset matrix is ​​applied to construct a spatially realigned ultrasonic matrix. Based on the acoustic-electric conversion coefficient and the duration of the ultrasonic pulse, the reverberation artifact energy distribution matrix is ​​calculated according to the difference between the original ultrasonic radio frequency echo envelope matrix and the spatially realigned ultrasonic matrix. Based on the system's absolute temperature, sound wave center wavelength, and total emitted transient sound intensity energy, calculate the thermal noise floor extremum and nonlinear projection convergence factor, constrain the reverberation artifact energy distribution matrix, and calculate the projection energy matrix. The inverse square root of the projected energy matrix is ​​used to calculate the reverberation artifact voltage matrix, which is then subtracted from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix.

[0029] Before performing the above steps, this embodiment first completes the initialization operation through the hardware system: establishing an acoustic detection coordinate system using the interventional ultrasound probe; establishing a device spatial motion monitoring channel using a position tracking sensor; and retrieving preset low-level physical constants such as acoustic-electric conversion coefficients and pulse durations from the system firmware memory.

[0030] Reference Figure 2 The calculation of the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and the determination of the acoustic impedance gradient tensor matrix, includes: Obtain the initial tissue acoustic impedance distribution matrix of the current detection area; Calculate the first-order spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, respectively; Add the square of the first spatial partial derivative in the horizontal direction to the square of the first spatial partial derivative in the vertical direction; The square root of the sum is taken to obtain the acoustic impedance gradient tensor matrix.

[0031] The step involves performing an exponential operation on the acoustic impedance gradient tensor matrix based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image to calculate the attenuation compensation factor matrix, including: Obtain the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image; The first product is obtained by multiplying the acoustic impedance gradient tensor matrix by the spatial physical resolution of the ultrasound image; The quotient is obtained by dividing the first product by the reference acoustic impedance of the interventional device coating. Take the negative of the quotient as the exponent, and perform exponential operation with the natural constant as the base to obtain the attenuation compensation factor matrix.

[0032] Reference Figure 3 The step of combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude, performing an arcsine operation on the attenuation compensation factor matrix, and calculating the local acoustic phase shift matrix includes: Obtain the original ultrasonic radio frequency echo envelope matrix of the current frame, and extract the global maximum voltage amplitude from the original ultrasonic radio frequency echo envelope matrix; The second product is obtained by multiplying the original ultrasonic radio frequency echo envelope matrix with the attenuation compensation factor matrix; Divide the second product by the global maximum voltage amplitude to obtain the ratio; Perform an arcsine operation on the ratio to obtain the local acoustic phase shift matrix.

[0033] The step of calculating the horizontal and vertical motion distortion flow field vector matrices based on the instantaneous spatial velocity field and the emission time interval of adjacent scan lines, combined with the local acoustic phase shift matrix, includes: Acquire the instantaneous horizontal and vertical velocity fields of the interventional device in the current frame, and acquire the emission time interval between adjacent scan lines; Multiplying the instantaneous horizontal velocity field, the emission time interval between adjacent scan lines, and the local acoustic phase offset matrix yields the horizontal motion distortion flow field vector matrix. Multiplying the instantaneous vertical velocity field, the emission time interval between adjacent scan lines, and the local acoustic phase offset matrix yields the vertical motion distortion flow field vector matrix.

[0034] The method involves resampling the original ultrasonic radio frequency echo envelope matrix using the motion-distorted flow field vector matrix with inverse coordinate offset, and applying cosine weights to the local acoustic phase offset matrix to construct a spatially realigned ultrasonic matrix, including: The coordinate offset is determined based on the horizontal motion distortion flow field vector matrix and the vertical motion distortion flow field vector matrix; The original ultrasonic radio frequency echo envelope matrix is ​​resampled by bilinear interpolation using the coordinate offset to obtain a resampled ultrasonic matrix. The cosine value of the local acoustic phase offset matrix is ​​calculated to obtain the cosine weight matrix; Multiplying the resampled ultrasound matrix by the cosine weight matrix yields the spatially realigned ultrasound matrix.

[0035] Reference Figure 4 The calculation of the reverberation artifact energy distribution matrix based on the acoustic-to-electrical conversion coefficient and the duration of the ultrasonic pulse, according to the difference between the original ultrasonic radio frequency echo envelope matrix and the spatially realigned ultrasonic matrix, includes: Obtain the acoustic-to-electric conversion coefficient and the duration of the ultrasonic pulse; The difference matrix is ​​obtained by subtracting the original ultrasound radio frequency echo envelope matrix from the spatially realigned ultrasound matrix. The sound pressure matrix is ​​obtained by multiplying the sound-to-electric conversion coefficients by the difference matrix; Calculate the square of the sound pressure matrix; The numerator is obtained by multiplying the squared value by the duration of the ultrasonic pulse; The denominator term is obtained by multiplying the reference acoustic impedance of the interventional device coating by a constant two. Dividing the numerator by the denominator yields the reverberation artifact energy distribution matrix.

[0036] The calculation of the thermal noise floor extremum and nonlinear projection convergence factor based on the system's absolute temperature, sound wave center wavelength, and total emitted transient sound intensity energy, constraining the reverberation artifact energy distribution matrix, and calculating the projection energy matrix includes: To obtain the normal absolute temperature of the human body, the center wavelength of the sound wave, and the total transient sound intensity energy emitted by the system; Multiplying the Boltzmann constant by the stated normal absolute temperature of the human body yields the product term; Dividing the product term by the square of the center wavelength of the sound wave yields the thermal noise floor extreme value; The energy sum is obtained by adding the reverberation artifact energy distribution matrix to the thermal noise floor extremum. Divide the total transient acoustic intensity energy emitted by the system by the sum of the energy values ​​and take the negative number as the projection exponent; The exponent is obtained by performing an exponential operation on the projected exponent with the natural constant as the base. Subtracting the exponent from the constant one yields the energy conservation projection factor matrix. Multiplying the reverberation artifact energy distribution matrix with the energy conservation projection factor matrix yields the projected energy matrix.

[0037] The step of performing inverse square root decomposition on the projected energy matrix to calculate the reverberation artifact voltage matrix, and subtracting it from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix includes: Multiply the constant 2, the reference acoustic impedance of the interventional device coating, and the projection energy matrix to obtain the divisor; The quotient is obtained by dividing the dividend by the duration of the ultrasonic pulse. The square root of the quotient term is taken to obtain the root matrix; the root matrix is ​​divided by the acoustic-electric conversion coefficient to obtain the reverberation artifact voltage matrix. The target ultrasound image matrix is ​​generated by subtracting the reverberation artifact voltage matrix from the original ultrasound radio frequency echo envelope matrix.

[0038] Example 2, based on Example 1, provides a further detailed description of the specific steps in a method for eliminating reverberation artifacts in interventional ultrasound images, including: The calculation of the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and the determination of the acoustic impedance gradient tensor matrix, include: The purpose of this step is to highlight the physical boundaries of structures in the image. To address the issue of conventional artifact removal filtering blurring the fine structures of real instrument tips, this approach does not process pixel grayscale. Instead, it first calculates the two-dimensional spatial gradient tensor of the real physical quantity, acoustic impedance, using this as the basis for distinguishing artifacts from real, strongly reflective interfaces. Before performing the calculation, the initial tissue acoustic impedance distribution matrix of the current detection area is obtained through basic acoustic transformation. ; The acoustic impedance gradient tensor matrix is ​​calculated using the following formula: In the formula, The acoustic impedance gradient tensor matrix; This is the initial tissue acoustic impedance distribution matrix.

[0039] By acquiring the initial tissue acoustic impedance distribution matrix of the current detection area, the first-order spatial partial derivatives of this initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions are calculated respectively. The squares of the first-order spatial partial derivatives in the horizontal and vertical directions are added together, and the square root of the sum is further performed to obtain the final acoustic impedance gradient tensor matrix. This method abandons the superficial processing method of smoothing pixel grayscale in traditional conventional artifact removal methods, and directly delves into the physical layer of ultrasound imaging to highlight the physical boundaries of the structure in the image. It can use the degree of change of the real physical quantity acoustic impedance as an objective basis to distinguish reverberation artifacts from real strong reflection interfaces. It effectively avoids the serious defect of conventional filtering processing in suppressing reverberation artifacts, which cannot accurately identify features and causes blurring of the fine structure of high dynamic instrument tips. While preserving the boundary information of real anatomical structures, it lays an extremely accurate physical morphological foundation for subsequent artifact removal, greatly improving the accuracy of low-level feature extraction and the resolution of medical diagnostic images.

[0040] The step involves performing an exponential operation on the acoustic impedance gradient tensor matrix based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image to calculate the attenuation compensation factor matrix, including: The purpose of this step is to suppress spurious gradient interference caused by the coating. The ultrasound-enhancing coating on the surface of the interventional device generates nonlinear acoustic attenuation, leading to spurious gradients in the gradient tensor that are remarkably similar to reverberation artifacts. To address this issue, this solution utilizes the intrinsic acoustic impedance of the coating and spatial resolution to construct an exponential attenuation compensation factor. Before performing this step, the system needs to obtain the reference acoustic impedance of the interventional device coating. Spatial physical resolution of ultrasound images ; The attenuation compensation factor matrix is ​​calculated using the following formula: In the formula, This is the attenuation compensation factor matrix; The acoustic impedance gradient tensor matrix; The spatial physical resolution of ultrasound images; The reference acoustic impedance for the coating of interventional devices.

[0041] By obtaining the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image, the acoustic impedance gradient tensor matrix calculated in the previous step is multiplied by the spatial physical resolution of the ultrasound image to obtain the first product. The first product is then divided by the reference acoustic impedance of the interventional device coating to obtain the corresponding quotient. The negative number of the quotient is then extracted as the exponent, and an exponential operation is performed with the natural constant as the base to finally construct the attenuation compensation factor matrix. This fully and specifically considers the underlying physical characteristic that modern interventional devices are usually coated with special ultrasound-enhancing coatings. The exponential attenuation compensation factor constructed using the intrinsic acoustic impedance and spatial resolution of the coating acts as an intelligent filter to intercept and suppress the artifact gradients caused by the nonlinear acoustic attenuation phenomenon of the coating. The calculated values ​​of these artifact gradient regions are nonlinearly compressed and forced to approach zero, thereby effectively preventing the system from misjudging the artifact gradients generated by the nonlinear acoustic attenuation of the device coating as real tissue boundaries or reverberation artifacts. This greatly improves the robustness and anti-interference suppression capability of subsequent artifact feature identification.

[0042] The step of combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude, performing an arcsine operation on the attenuation compensation factor matrix, and calculating the local acoustic phase shift matrix includes: The purpose of this step is to map the voltage amplitude signal to acoustic phase distortion characteristics. Based on the calculated compensation factor, this scheme needs to quantify the degree of phase shift caused by reverberation in the original signal for subsequent positioning and separation. Before performing this step, the system synchronously acquires the original ultrasonic radio frequency echo envelope matrix of the current frame using an interventional ultrasonic probe. ; The local acoustic phase shift matrix is ​​calculated using the following formula: In the formula, This is the local acoustic phase shift matrix; This is the original ultrasonic radio frequency echo envelope matrix of the current frame; This is the attenuation compensation factor matrix; For the current frame matrix The global maximum voltage amplitude.

[0043] By acquiring the original ultrasonic radio frequency echo envelope matrix of the current frame and accurately extracting the global maximum voltage amplitude from the matrix, the original ultrasonic radio frequency echo envelope matrix is ​​multiplied by the previously constructed attenuation compensation factor matrix to obtain a second product. Then, the second product is divided by the global maximum voltage amplitude to obtain a normalized ratio. Finally, an arcsine operation is performed on the ratio to calculate the local acoustic phase shift matrix. This achieves the accurate mapping of the chaotic voltage amplitude signal on the surface into the acoustic phase distortion characteristics of the underlying layer. It cleverly combines the compensation factor that filters out coating interference to recalibrate the detection signal. This not only objectively quantifies the severity of the physical phase shift caused by multiple reflections and reverberation of sound waves in the original ultrasonic signal, but also significantly amplifies the distortion and twisting details of the artifact region by utilizing the nonlinear stretching characteristics of the arcsine function. This provides a direct mathematical direction and physical judgment basis for the subsequent accurate spatial positioning and independent separation and extraction of free artifact components, overcoming the technical bottleneck of relying solely on voltage amplitude for threshold segmentation, which is prone to interference and misjudgment.

[0044] The step of calculating the horizontal and vertical motion distortion flow field vector matrices based on the instantaneous spatial velocity field and the emission time interval of adjacent scan lines, combined with the local acoustic phase shift matrix, includes: This step quantifies the physical deformation of the image over time. During phase offset compensation, due to the time difference between adjacent scan lines, the physical movement of the instrument during scanning causes spatial and temporal misalignment and distortion of the original phase offset matrix. To address this issue, this scheme constructs an independent flow field vector matrix by incorporating the motion velocity field. Before calculation, the instantaneous horizontal velocity field of the interventional instrument in the current frame is obtained using a position tracking sensor. With instantaneous perpendicular velocity field And obtain the emission time interval between adjacent scan lines. ; The horizontal motion distortion flow field vector matrix is ​​calculated using the following formula: In the formula, The vector matrix of the horizontal motion distortion flow field; This represents the instantaneous horizontal velocity field. The time interval between the emission of adjacent scan lines; This is the local acoustic phase shift matrix; The vertical motion distortion flow field vector matrix is ​​calculated using the following formula: In the formula, The vector matrix of the vertical motion distortion flow field; This represents the instantaneous vertical velocity field. The time interval between the emission of adjacent scan lines; This is the local acoustic phase shift matrix.

[0045] By acquiring the instantaneous horizontal and vertical velocity fields of the interventional device in the current frame, as well as the emission time interval of adjacent scan lines, the instantaneous horizontal velocity field is multiplied together with the emission time interval of adjacent scan lines and the local acoustic phase offset matrix obtained in the previous step to obtain the horizontal motion distortion flow field vector matrix. Simultaneously, the instantaneous vertical velocity field is multiplied together with the emission time interval of adjacent scan lines and the local acoustic phase offset matrix to obtain the vertical motion distortion flow field vector matrix. This fully considers and deeply quantifies the physical deformation law of ultrasound images in dynamic continuous scanning sequence, breaking the limitation of existing processing schemes that usually treat ultrasound images as an absolutely static section for isolated calculation. A special mathematical model was developed for the image position offset caused by the superposition of intra-frame scan line emission time difference and instantaneous spatial motion of medical devices during interventional operations. The actual horizontal and vertical deviation distances of each physical point in the image due to the scanning time difference and physical motion of the device were accurately calculated, providing indispensable dynamic reverse flow field parameter support for completely solving the serious spatiotemporal misalignment distortion problem.

[0046] The method involves resampling the original ultrasonic radio frequency echo envelope matrix using the motion-distorted flow field vector matrix with inverse coordinate offset, and applying cosine weights to the local acoustic phase offset matrix to construct a spatially realigned ultrasonic matrix, including: The purpose of this step is to eliminate motion distortion and restore the true spatial location of reverberation artifacts. Using the obtained motion distortion flow field, inverse physical displacement compensation is performed on the original image, and phase weights are applied to accurately align the structural features of the reverberation artifacts to a unified time reference.

[0047] The spatially realigned ultrasound matrix is ​​calculated using the following formula: In the formula, To spatially realign the ultrasound matrix; This is the original ultrasonic radio frequency echo envelope matrix, which is then processed by inputting coordinate offsets. Perform bilinear interpolation resampling; The vector matrix of the horizontal motion distortion flow field; The vector matrix of the vertical motion distortion flow field; This is the local acoustic phase shift matrix.

[0048] The spatial coordinate offset of a pixel is determined by jointly using the horizontal motion distortion flow field vector matrix and the vertical motion distortion flow field vector matrix obtained in the previous step. This coordinate offset is then used to perform bilinear interpolation resampling on the original ultrasonic radio frequency echo envelope matrix to obtain a resampled ultrasonic matrix. The cosine value of the local acoustic phase offset matrix is ​​calculated to obtain the corresponding cosine weight matrix. Finally, the resampled ultrasonic matrix is ​​multiplied by the cosine weight matrix to construct a spatially realigned ultrasonic matrix. A reverse spatiotemporal compensation correction mechanism for the microscopic time difference of ultrasonic dynamic scanning is established. The motion distortion flow field parameters are used to reverse and forcibly pull the physical coordinates of the original image that has been misaligned back to the absolutely correct position, just like time rewind. The cosine weight reflecting the phase dynamic deformation is innovatively applied to effectively correct the physical reception intensity of the underlying signal. This completely eliminates the spatial and temporal distortion caused by the superposition of scanning time difference by the tiny movement of the instrument. The true reverberation artifact structure features hidden in the cluttered ultrasonic background are aligned to a unified time reference measurement plane with extremely high precision, and the true spatial position and shape of the reverberation artifact are exposed with extremely high accuracy.

[0049] The calculation of the reverberation artifact energy distribution matrix based on the acoustic-to-electrical conversion coefficient and the duration of the ultrasonic pulse, according to the difference between the original ultrasonic radio frequency echo envelope matrix and the spatially realigned ultrasonic matrix, includes: This step converts the aligned voltage difference into actual acoustic energy density. By comparing the original image and the realigned image, the free reverberation artifact component is extracted and mapped to energy distribution using the principle of acoustic work. Before performing the calculation, the acoustic-to-electrical conversion coefficients need to be obtained. Duration of ultrasound pulse ; The reverberation artifact energy distribution matrix is ​​calculated using the following formula: In the formula, The reverberation artifact energy distribution matrix; The sound-to-electric conversion coefficient; This is the original ultrasonic radio frequency echo envelope matrix; To spatially realign the ultrasound matrix; The duration of the ultrasonic pulse; The reference acoustic impedance for the instrument coating.

[0050] By obtaining the underlying acoustic-electric conversion coefficients and the duration of the ultrasonic pulse, the original ultrasonic radio frequency echo envelope matrix is ​​subtracted from the previously constructed spatially realigned ultrasonic matrix to obtain the difference matrix. The acoustic-electric conversion coefficients are then multiplied by this difference matrix to obtain the sound pressure matrix, and its square is calculated. This squared value is then multiplied by the ultrasonic pulse duration as the numerator, while the reference acoustic impedance of the interventional device coating is multiplied by a constant two as the denominator. Finally, the numerator is divided by the denominator to calculate the reverberation artifact energy distribution matrix. This method strictly follows the law of conservation of energy in the dynamic physical environment of the objective sound field, completely abandoning the current... In image processing techniques, the arithmetic logic fallacy and energy information distortion caused by directly using grayscale or voltage signals for subtraction are addressed by rigorously comparing the original signal image with the realigned image. This successfully separates and extracts the abnormal components of free reverberation artifacts. Furthermore, by employing rigorous underlying physical conversion logic, the differences in surface electrical signals are transformed into the actual physical quantity of acoustic work done, namely absolute energy density. This method precisely quantifies the absolute physical energy contained in the reverberation artifacts that urgently need to be completely eliminated, establishing an extremely reliable and scientifically sound energy domain calibration benchmark for subsequent safe energy deduction calculations.

[0051] The calculation of the thermal noise floor extremum and nonlinear projection convergence factor based on the system's absolute temperature, sound wave center wavelength, and total emitted transient sound intensity energy, constraining the reverberation artifact energy distribution matrix, and calculating the projection energy matrix includes: This step aims to prevent illegal energy leakage during artifact stripping. When directly subtracting the separated energy from the original image, abrupt energy changes at the tissue-artifact boundary can cause a negative energy "black hole" (ghosting) after subtraction. To address this issue, this method introduces energy conservation projection. This step requires prior acquisition of the human body's normal absolute temperature. , center wavelength of sound waves and the total transient acoustic intensity energy emitted by the system ; The extreme value of the thermal noise floor is calculated using the following formula: In the formula, This represents the extreme value of the thermal noise floor. Boltzmann's constant; The normal absolute temperature of the human body; The center wavelength of the sound wave; The energy conservation projection factor matrix is ​​calculated using the following formula: In the formula, The energy conservation projection factor matrix; This represents the total transient acoustic intensity energy emitted by the system. The reverberation artifact energy distribution matrix; This represents the extreme value of the thermal noise floor. The projected energy matrix is ​​calculated using the following formula: In the formula, For the projected energy matrix; The reverberation artifact energy distribution matrix; This is the energy conservation projection factor matrix.

[0052] By obtaining the normal absolute temperature of the human body, the center wavelength of the sound wave, and the total emitted transient sound intensity energy of the system, the product of the Boltzmann constant and the normal absolute temperature of the human body is divided by the square of the center wavelength of the sound wave to obtain the extreme value of the thermal noise floor. The reverberation artifact energy distribution matrix is ​​then added to this extreme value of the thermal noise floor as the energy sum. Subsequently, the total emitted transient sound intensity energy of the system is divided by this energy sum, and its negative value is used as the projection exponent for exponential calculation of the natural constant base. The result is subtracted from the constant to obtain the energy conservation projection factor matrix, which is then multiplied by the reverberation artifact energy distribution matrix to obtain the projected energy matrix. This interdisciplinary approach introduces a unified... The underlying limit parameters in thermodynamics and physics have successfully constructed a safety threshold valve to prevent the complete collapse of image energy. The mathematical and physical bottom limit value is cleverly set to avoid the collapse of the division arithmetic singularity. It effectively ensures that the reverberation artifact energy can be subject to extremely smooth nonlinear convergence constraint as it approaches the physical threshold of the transient sound intensity energy of the total emission of the system. This fundamentally prevents the serious phenomenon of excessive energy deduction and illegal leakage when stripping artifacts. It completely solves the malignant calculation defects of traditional algorithms that easily lead to serious ghosting and negative energy black holes at the abrupt change at the boundary between real tissue and artifact, which violate the laws of physics.

[0053] The step of performing inverse square root decomposition on the projected energy matrix to calculate the reverberation artifact voltage matrix, and subtracting it from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix includes: The purpose of this step is to complete the final image restoration output. The strictly controlled projected energy matrix is ​​inversely solved back to the ultrasonic receiving voltage dimension, and the final subtraction operation is performed on the original signal matrix to completely output a clean image free of reverberation artifacts.

[0054] The reverberation artifact voltage matrix is ​​calculated using the following formula: In the formula, The voltage matrix for reverberation artifacts; The sound-to-electric conversion coefficient; The duration of the ultrasonic pulse; The reference acoustic impedance for the instrument coating; For the projected energy matrix; The final image is generated using the following formula: In the formula, To eliminate reverberation artifacts in the target ultrasound image matrix; This is the original ultrasonic radio frequency echo envelope matrix; For the reverberation artifact voltage matrix, this This refers to the artifact-free interventional ultrasound image data that is ultimately output by the entire technical solution and used for display.

[0055] By multiplying the constant 2 with the reference acoustic impedance of the interventional device coating and the projected energy matrix (which has undergone safety limit verification in the preceding steps) to obtain the dividend, and then dividing the dividend by the ultrasound pulse duration to obtain the quotient, the square root of this quotient is obtained. This quotient is then divided by the acoustic-to-electrical conversion coefficient to inversely and losslessly reconstruct the reverberation artifact voltage matrix. Finally, the original ultrasound radio frequency echo envelope matrix is ​​subtracted from this highly accurate calculated reverberation artifact voltage matrix to generate the target ultrasound image matrix. This establishes and completes a highly rigorous cross-domain inverse mapping closed-loop transformation from the energy physics domain to the underlying voltage domain. The computer mechanism re-translates and reverse-engineers the projected energy, which is strictly controlled and absolutely conforms to the physical constraints of dynamic energy conservation, into a real electrical signal in the voltage dimension that can be directly understood and processed by the underlying ultrasound hardware receiving device. Then, it safely and smoothly performs the final precise physical magnitude subtraction and blanking operation in the most original broadband signal matrix. Like peeling an onion, it thoroughly and precisely peels away and completely eliminates false reverberation interference components from the complex and ever-changing background reflected ultrasound signal of biological tissue. Finally, it outputs high-quality real-time images for minimally invasive interventional medical diagnosis that are not only completely free of severe reverberation artifacts but also have absolutely clear and faithful underlying anatomical structures.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for eliminating reverberation artifacts in interventional ultrasound images, characterized in that, include: Calculate the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and obtain the acoustic impedance gradient tensor matrix. Based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image, the attenuation compensation factor matrix is ​​calculated by performing an exponential operation on the acoustic impedance gradient tensor matrix. By combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude, an arcsine operation is performed on the attenuation compensation factor matrix to calculate the local acoustic phase shift matrix. Based on the instantaneous spatial velocity field and the emission time interval of adjacent scan lines, and combined with the local acoustic phase shift matrix, the horizontal and vertical motion distortion flow field vector matrices are calculated respectively. The original ultrasonic radio frequency echo envelope matrix is ​​resampled by inverse coordinate offset using the motion distortion flow field vector matrix, and a cosine weight of the local acoustic phase offset matrix is ​​applied to construct a spatially realigned ultrasonic matrix. Based on the acoustic-to-electrical conversion coefficient and the duration of the ultrasonic pulse, the reverberation artifact energy distribution matrix is ​​calculated according to the difference between the original ultrasonic radio frequency echo envelope matrix and the spatially realigned ultrasonic matrix, including: Obtain the acoustic-to-electric conversion coefficient and the duration of the ultrasonic pulse; The difference matrix is ​​obtained by subtracting the original ultrasound radio frequency echo envelope matrix from the spatially realigned ultrasound matrix. The sound pressure matrix is ​​obtained by multiplying the sound-to-electric conversion coefficients by the difference matrix; Calculate the square of the sound pressure matrix; The numerator is obtained by multiplying the squared value by the duration of the ultrasonic pulse; The denominator term is obtained by multiplying the reference acoustic impedance of the interventional device coating by a constant two. Dividing the numerator by the denominator yields the reverberation artifact energy distribution matrix; Based on the system's absolute temperature, sound wave center wavelength, and total emitted transient sound intensity energy, the thermal noise floor extremum and nonlinear projection convergence factor are calculated. The reverberation artifact energy distribution matrix is ​​constrained, and the projection energy matrix is ​​calculated, including: To obtain the normal absolute temperature of the human body, the center wavelength of the sound wave, and the total transient sound intensity energy emitted by the system; Multiplying the Boltzmann constant by the stated normal absolute temperature of the human body yields the product term; Dividing the product term by the square of the center wavelength of the sound wave yields the thermal noise floor extreme value; The energy sum is obtained by adding the reverberation artifact energy distribution matrix to the thermal noise floor extremum. Divide the total transient acoustic intensity energy emitted by the system by the sum of the energy values ​​and take the negative number as the projection exponent; The exponent is obtained by performing an exponential operation on the projected exponent with the natural constant as the base. Subtracting the exponent from the constant one yields the energy conservation projection factor matrix. Multiplying the reverberation artifact energy distribution matrix by the energy conservation projection factor matrix yields the projected energy matrix; The inverse square root of the projected energy matrix is ​​used to calculate the reverberation artifact voltage matrix, which is then subtracted from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix.

2. The method for eliminating reverberation artifacts in interventional ultrasound images according to claim 1, characterized in that, The calculation of the spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, and the determination of the acoustic impedance gradient tensor matrix, include: Obtain the initial tissue acoustic impedance distribution matrix of the current detection area; Calculate the first-order spatial partial derivatives of the initial tissue acoustic impedance distribution matrix in the horizontal and vertical directions, respectively; Add the square of the first spatial partial derivative in the horizontal direction to the square of the first spatial partial derivative in the vertical direction; The square root of the sum is taken to obtain the acoustic impedance gradient tensor matrix.

3. The method for eliminating reverberation artifacts in interventional ultrasound images according to claim 2, characterized in that, The step involves performing an exponential operation on the acoustic impedance gradient tensor matrix based on the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image to calculate the attenuation compensation factor matrix, including: Obtain the reference acoustic impedance of the interventional device coating and the spatial physical resolution of the ultrasound image; The first product is obtained by multiplying the acoustic impedance gradient tensor matrix by the spatial physical resolution of the ultrasound image; The quotient is obtained by dividing the first product by the reference acoustic impedance of the interventional device coating. Take the negative of the quotient as the exponent, and perform exponential operation with the natural constant as the base to obtain the attenuation compensation factor matrix.

4. The method for eliminating reverberation artifacts in interventional ultrasound images according to claim 3, characterized in that, The step of combining the original ultrasonic radio frequency echo envelope matrix of the current frame and its global maximum voltage amplitude, performing an arcsine operation on the attenuation compensation factor matrix, and calculating the local acoustic phase shift matrix includes: Obtain the original ultrasonic radio frequency echo envelope matrix of the current frame, and extract the global maximum voltage amplitude from the original ultrasonic radio frequency echo envelope matrix; The second product is obtained by multiplying the original ultrasonic radio frequency echo envelope matrix with the attenuation compensation factor matrix; Divide the second product by the global maximum voltage amplitude to obtain the ratio; Perform an arcsine operation on the ratio to obtain the local acoustic phase shift matrix.

5. The method for eliminating reverberation artifacts in interventional ultrasound images according to claim 4, characterized in that, The step of calculating the horizontal and vertical motion distortion flow field vector matrices based on the instantaneous spatial velocity field and the emission time interval of adjacent scan lines, combined with the local acoustic phase shift matrix, includes: Acquire the instantaneous horizontal and vertical velocity fields of the interventional device in the current frame, and acquire the emission time interval between adjacent scan lines; Multiplying the instantaneous horizontal velocity field, the emission time interval between adjacent scan lines, and the local acoustic phase offset matrix yields the horizontal motion distortion flow field vector matrix. Multiplying the instantaneous vertical velocity field, the emission time interval between adjacent scan lines, and the local acoustic phase offset matrix yields the vertical motion distortion flow field vector matrix.

6. The method for eliminating reverberation artifacts in interventional ultrasound images according to claim 5, characterized in that, The method involves resampling the original ultrasonic radio frequency echo envelope matrix using the motion-distorted flow field vector matrix with inverse coordinate offset, and applying cosine weights to the local acoustic phase offset matrix to construct a spatially realigned ultrasonic matrix, including: The coordinate offset is determined based on the horizontal motion distortion flow field vector matrix and the vertical motion distortion flow field vector matrix; The original ultrasonic radio frequency echo envelope matrix is ​​resampled by bilinear interpolation using the coordinate offset to obtain a resampled ultrasonic matrix. The cosine value of the local acoustic phase offset matrix is ​​calculated to obtain the cosine weight matrix; Multiplying the resampled ultrasound matrix by the cosine weight matrix yields the spatially realigned ultrasound matrix.

7. The method for eliminating reverberation artifacts in interventional ultrasound images according to claim 6, characterized in that, The step of performing inverse square root decomposition on the projected energy matrix to calculate the reverberation artifact voltage matrix, and subtracting it from the original ultrasound radio frequency echo envelope matrix to generate the target ultrasound image matrix includes: Multiply the constant 2, the reference acoustic impedance of the interventional device coating, and the projection energy matrix to obtain the divisor; The quotient is obtained by dividing the dividend by the duration of the ultrasonic pulse. The square root of the quotient term is taken to obtain the root matrix; the root matrix is ​​divided by the acoustic-electric conversion coefficient to obtain the reverberation artifact voltage matrix. The target ultrasound image matrix is ​​generated by subtracting the reverberation artifact voltage matrix from the original ultrasound radio frequency echo envelope matrix.

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