A system and method for real-time three-dimensional ultrasonic elastic imaging

Abstract

The present invention provides a system and method for real-time three-dimensional ultrasonic elastic imaging. By using row-column addressed probes to perform three-dimensional imaging, the number of probe array elements is relatively low, and conventional ultrasonic systems can be implemented with relatively low cost. The row-column addressed probes are used to perform three-dimensional elastic imaging, and the complexity of the three-dimensional reconstruction algorithm is relatively low and easy to implement. Specifically, based on the row-column addressed array probe, a long pulse excitation is performed on the region of interest to generate shear waves in the region of interest; based on the row-column addressed array probe, a pulse excitation is performed on the region of interest that generates the three-dimensional shear wave to generate ultrasonic waves in the region of interest, and beam synthesis and reconstruction are performed based on the echo signal to obtain a three-dimensional data frame sequence, and the velocity distribution of the shear wave in the region of interest is calculated to finally obtain a three-dimensional ultrasonic elastic image. Through direct three-dimensional imaging, the deformation and distortion of the three-dimensional target elastic imaging caused by the movement and breathing of the observed object is reduced, so as to ensure that the obtained three-dimensional ultrasonic elastic image can accurately and comprehensively display the characteristics of the lesion.

Description

Technical Field

[0001] The present invention relates to the technical field of image processing, and in particular to a system and method for real-time three-dimensional ultrasonic elastic imaging. Background Art

[0002] Ultrasound elastography is a medical imaging technique that provides information about the physical characteristics of tissues (such as hardness, viscoelasticity, etc.) by measuring the response of tissues to stress or compression, thereby helping doctors diagnose and monitor various diseases. Shear wave elastography is a type of elastography that assesses tissue hardness by applying shear force to the tissue and measuring the propagation speed of the generated shear wave to calculate the Young's modulus of the tissue. The harder the tissue, the faster the shear wave propagates; the softer the tissue, the slower the shear wave propagates.

[0003] Two-dimensional shear wave elastic imaging technology has a wide range of scientific research and clinical applications in medical diagnosis. Compared with two-dimensional imaging, three-dimensional ultrasound imaging can provide more comprehensive and realistic stereoscopic images, allowing doctors to better understand and evaluate the morphology, structure and positional relationship of organs or lesions. The data generated by three-dimensional ultrasound imaging can be used for subsequent three-dimensional reconstruction, stereo measurement and volume calculation, which helps doctors to conduct more comprehensive and accurate analysis and evaluation, help reduce the misdiagnosis rate caused by limited observation angles, and improve the accuracy of diagnosis.

[0004] A method of reconstructing a three-dimensional elastic image by driving an ultrasonic probe with a mechanical motor to scan multiple static two-dimensional elastic images. Although this method can obtain a three-dimensional elastic image, the imaging speed is slow and real-time three-dimensional elastic imaging cannot be achieved.

[0005] A method of three-dimensional imaging through a two-dimensional matrix probe. Using a two-dimensional matrix probe, the target can be directly reconstructed and imaged in three dimensions. However, this method has problems such as high system cost, complex implementation and calculation.

[0006] The main problems with current 3D elastography include:

[0007] (1) The imaging speed is very slow and real-time imaging cannot be achieved, which affects the dynamic observation of the lesion.

[0008] (2) Due to the long imaging time, the movement of the measured tissue during the imaging process will cause deformation and distortion of the three-dimensional target elastic imaging.

[0009] (3) The use of two-dimensional matrix probes for three-dimensional elastic imaging has disadvantages such as high cost and complex system implementation and calculation. Summary of the invention

[0010] The present invention provides a real-time three-dimensional ultrasonic elastic imaging system and method to solve the problems raised in the background technology.

[0011] A real-time three-dimensional ultrasonic elastic imaging system, comprising:

[0012] An excitation module, used for performing long pulse excitation on the region of interest based on a row-column addressing array probe to generate shear waves in the region of interest, and also used for controlling the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest;

[0013] An acquisition module is used to acquire ultrasonic echo signals generated by ultrasonic pulse excitation in the region of interest and convert the ultrasonic echo signals into digital echo signals;

[0014] A beamforming module, used for performing beamforming reconstruction based on the digital echo signal to obtain a three-dimensional data frame sequence;

[0015] The imaging module is used to obtain the velocity distribution of shear waves in the region of interest based on the three-dimensional data frame sequence, determine the three-dimensional elastic distribution based on the velocity distribution, and obtain a three-dimensional ultrasonic elastic image based on the three-dimensional elastic distribution.

[0016] Preferably, it also includes a region determination module, used to determine a region of interest;

[0017] There are two ways to determine the area of ​​interest:

[0018] Manual determination method, the user manually selects the region of interest based on the grayscale image;

[0019] Automatic outlining mode, based on the analysis of grayscale images, automatically selects the region of interest, including:

[0020] A processing unit, used to determine an initial detection area based on medical diagnosis requirements, and perform preliminary processing on the initial detection area to obtain image features;

[0021] A division unit, used for dividing the initial detection area based on image features to obtain multiple detection areas;

[0022] The selection unit is used to select a detection area whose feature difference between an image feature and a preset image feature is within a preset range as a region of interest.

[0023] Preferably, the shear wave excitation module comprises:

[0024] The excitation unit is used to perform long pulse excitation on each array element row in the row-column addressing array, and the generated wave is focused on different emission focal points of the row-column addressing array, thereby generating shear waves propagating in the target area.

[0025] Preferably, the excitation module is used to control the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest, including:

[0026] The transmitting unit is used for applying characteristic delayed ultrasonic pulse excitation to the array element after the row and column addressing array probe generates shear waves in the area of ​​interest, so as to generate focused or unfocused ultrasonic waves at different angles.

[0027] Preferably, the acquisition module includes:

[0028] A signal acquisition unit, used for acquiring ultrasonic echo signals generated by ultrasonic waves propagating in the region of interest;

[0029] The conversion unit is used to convert the ultrasonic echo signal into a digital echo signal based on an analog-to-digital converter.

[0030] Preferably, the beamforming module comprises:

[0031] The time calculation unit is used to calculate the total propagation time of the ultrasonic wave from the time t when the transmit beam is emitted to the time when the sound wave propagates to point P and is then received by the kth array element in the receiving array according to the following formula:

[0032]

[0033] in, represents the overall propagation time, Represents the vertical distance from the target point P to the center line of the transmitting aperture, represents the vertical distance from the target point P to the kth receiving array element, and c represents the propagation speed of the ultrasonic echo signal in the area of ​​interest;

[0034] The synthesis unit is used to calculate the reconstructed echo signal at the target point P according to the following formula ;

[0035]

[0036] Where w(k) is the weight coefficient, N represents the number of receiving array elements involved in the reconstruction calculation, represents the echo signal collected by the kth receiving element at time t;

[0037] A three-dimensional data frame sequence is obtained based on the echo signal reconstructed at the target point P.

[0038] Preferably, the imaging module comprises:

[0039] The calculation unit is further used to calculate the three-dimensional elastic image at time t according to the following formula based on the speed of the three-dimensional data frame sequence at time t;

[0040] E(t) = 3ρ‧c(t)^2

[0041] Where ρ is the tissue density of the region of interest, c(t) represents the three-dimensional distribution of shear wave velocity in the target area at time t;

[0042] A composite processing unit, used for composite processing of three adjacent frame signals based on the following formula to obtain a three-dimensional elastic distribution at time t;

[0043]

[0044] in, represents the weighted three-dimensional elastic image, E(t) represents the three-dimensional elastic image at time t, dt is the time interval between the generation of two three-dimensional elastic images, E(t-dt) and E(t-2*dt) are the three-dimensional elastic distributions at time t-dt and t-2*dt respectively, w1 represents the first weight coefficient, w2 represents the second weight coefficient, and w3 represents the third weight coefficient;

[0045] The imaging unit is used to obtain the three-dimensional elastic distribution based on the three-dimensional elastic characteristics at all times, and to perform three-dimensional imaging using a preset visualization method to obtain a three-dimensional ultrasonic elastic image.

[0046] A method for real-time three-dimensional ultrasonic elastic imaging system, comprising:

[0047] S1: Based on the row-column addressing array probe, long pulse excitation is performed on the region of interest to generate shear waves in the region of interest. It is also used to control the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest.

[0048] S2: collecting ultrasonic echo signals generated by ultrasonic pulse excitation in the region of interest, and converting the ultrasonic echo signals into digital echo signals;

[0049] S3: Performing beamforming reconstruction based on the digital echo signal to obtain a three-dimensional data frame sequence;

[0050] S4: Based on the three-dimensional data frame sequence, the velocity distribution of the shear wave in the region of interest is obtained, the three-dimensional elastic distribution is determined based on the velocity distribution, and the three-dimensional ultrasonic elastic image is obtained based on the three-dimensional elastic distribution.

[0051] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0052] Use a row-column addressed area array probe to perform real-time shear wave three-dimensional elastic imaging;

[0053] Use a long electric pulse sequence to excite the row-column addressed area array probe, focus on the target area, and excite shear waves propagating in a specific direction in three-dimensional space;

[0054] Use an electric pulse sequence to excite the row-column addressed array probe to excite ultrasound waves (including focused waves, plane waves, and scattered waves) covering three-dimensional space to stimulate the area of ​​interest;

[0055] Using a row-column addressed area array probe, the echo signal is acquired and reconstructed to form three-dimensional image data of the space of interest. The reconstruction methods include focused wave, plane wave and scattered wave.

[0056] Using a row-column addressed area array probe, the three-dimensional image data of the space of interest is obtained, and the propagation speed and direction of the shear wave in the space of interest are calculated;

[0057] Using a row-column addressed area array probe, the three-dimensional image data of the space of interest is obtained, and then the shear wave velocity distribution and Young's modulus distribution of the region of interest are calculated;

[0058] Use a row-column addressed area array probe to perform real-time shear wave three-dimensional elastic imaging, and display the three-dimensional elastic imaging images in a variety of ways;

[0059] Use a row-column addressed area array probe to perform real-time shear wave three-dimensional elastic imaging, and perform multiple measurement and analysis on the three-dimensional elastic imaging images;

[0060] Use a row-column addressed area array probe to perform real-time shear wave three-dimensional elastic imaging at multiple spatial locations within the space of interest, and perform weighted composite on the results to improve image quality;

[0061] The three-dimensional elastic data frames collected at different times are processed to improve the stability, accuracy and reliability of three-dimensional elastic imaging.

[0062] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in this application document.

[0063] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0065] Figure 1 A structural diagram of a real-time three-dimensional ultrasonic elastography system according to an embodiment of the present invention;

[0066] Figure 2It is a schematic diagram of the structure of a row-column addressing array probe in an embodiment of the present invention;

[0067] Figure 3 A coordinate system definition diagram of a row-column addressing array probe in an embodiment of the present invention;

[0068] Figure 4 A schematic diagram of shear wave generation in an embodiment of the present invention;

[0069] Figure 5 is a schematic diagram of a shear wave plane in an embodiment of the present invention;

[0070] Figure 6 Schematic diagram of the scanning and processing process of three-dimensional elastic imaging in an embodiment of the present invention. DETAILED DESCRIPTION

[0071] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0072] Embodiment 1:

[0073] The embodiment of the present invention provides a real-time three-dimensional ultrasonic elastic imaging system. Figure 1 As shown, including:

[0074] An excitation module, used for performing long pulse excitation on the region of interest based on a row-column addressing array probe to generate shear waves in the region of interest, and also used for controlling the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest;

[0075] An acquisition module is used to acquire ultrasonic echo signals generated by ultrasonic pulse excitation in the region of interest and convert the ultrasonic echo signals into digital echo signals;

[0076] A beamforming module, used for performing beamforming reconstruction based on the digital echo signal to obtain a three-dimensional data frame sequence;

[0077] The imaging module is used to obtain the velocity distribution of shear waves in the region of interest based on the three-dimensional data frame sequence, determine the three-dimensional elastic distribution based on the velocity distribution, and obtain a three-dimensional ultrasonic elastic image based on the three-dimensional elastic distribution.

[0078] In this embodiment, the row-column addressing array probe is referred to as an RCA probe.

[0079] In this embodiment, the composition structure of the row and column addressing array probe is as follows: Figure 2As shown. The row-column addressing array probe consists of an array element row 301 and an array element column 302. The array element row includes m array elements, and the array element column includes n array elements. Usually, the number of array elements in the row and column of the row-column addressing array probe is equal. In the present invention, the number of array elements in the row and column is N to simplify the description. Each array element is connected to the ultrasound host through a connecting cable 303. The number of cables required is 2N, which is greatly reduced compared to the traditional area array probe that requires N^2 connecting cables, greatly simplifying the system design.

[0080] In this embodiment, the array element rows and array element columns of the row-column addressing array probe can be used as a transmitting array or a receiving array. Figure 3 As shown, the coordinate system definition of the row and column addressing array probe and the basic imaging principle are shown. Figure 3 In the figure, the array element row is used as the transmitting array 302T, and the transmitting beam 402 is formed by applying pulse excitations with different delays to different array elements. The transmitting beam is a three-dimensional space ultrasound wave symmetrically distributed along the transmitting center plane 401. The array element column is used as the receiving array 302R to receive the echo signal. The basic principle of the RCA array probe for three-dimensional imaging is similar to that of ultrasonic two-dimensional imaging, and both can use the delay accumulation method.

[0081] In this embodiment, focused ultrasound waves can be generated by applying electric pulse sequences with different delays to array element rows or array element columns. Figure 4 As shown, Figure 4 The middle left figure shows the shear wave generated by exciting the array element row 302T and focusing it at the emission focus 403. Using long pulses to excite each row of array elements will excite a shear wave 501 that propagates laterally at the depth of the emission focus 403. The wavefront shape of the shear wave is similar to a cylinder. By using long pulses to excite shear waves at focal positions at different depths, a uniformly propagating shear wave plane 502 can be obtained in the detection area, as shown in Figure 5. Figure 5 shown.

[0082] In this embodiment, the scanning and processing of 3D elastic imaging is as follows: Figure 6 As shown, firstly, the target area is excited by 3D shear waves, and then a sequence of 3D data frames is quickly collected. The time interval between two adjacent 3D data frames is PRT, and a total of M 3D data frames are collected. Each 3D data frame can be 3D volume data 601 reconstructed by a single emission, or can be a composite of 3D volume data reconstructed by multiple emissions at different angles. Figure 6The three-dimensional data frame Vol(1) in the figure is composed of three plane waves at three different angles (-5 degrees, 0 degrees and +5 degrees) that are excited and reconstructed into a composite of three-dimensional volume data. By calculating the displacement of two adjacent frames in the reconstructed three-dimensional data frame sequence, three-dimensional shear wave velocity distribution data 602 can be obtained. In the actual implementation process, the number of plane wave angles and specific values ​​can be adjusted and changed according to actual conditions.

[0083] The beneficial effects of the above-mentioned design scheme are as follows: by using row-column addressed probes for three-dimensional imaging, the number of probe array elements is relatively low, which can be realized by conventional ultrasound systems and has relatively low costs; by using row-column addressed probes for three-dimensional elastic imaging, the amount of data processed is relatively small, the complexity of the three-dimensional reconstruction algorithm is relatively low and easy to implement; a method of sequentially exciting multiple pulses is used to generate shear waves that propagate in three dimensions, and the propagation coverage range is large and the wavefront is approximately plane, which is beneficial to improving the accuracy of elastic calculations; specifically, based on the row-column addressed array probe, a long pulse is excited on the region of interest to generate shear waves in the region of interest; based on the row-column addressed array probe, a one-pulse excitation is performed on the region of interest for generating three-dimensional shear waves to generate ultrasonic waves in the region of interest, and the echo signals of the collected ultrasonic waves are converted into digital signals; beam synthesis reconstruction is performed based on the echo signals to obtain a three-dimensional data frame sequence; based on the three-dimensional data frame sequence, the velocity distribution of the shear wave in the region of interest is obtained, and based on the velocity distribution, a three-dimensional ultrasonic elastic image is obtained, and through direct three-dimensional imaging, the deformation and distortion of the three-dimensional target elastic imaging are reduced, the computational complexity is reduced, and it is ensured that the obtained three-dimensional ultrasonic elastic image can accurately and comprehensively display the characteristics of the lesion.

[0084] Embodiment 2:

[0085] Based on Example 1, an embodiment of the present invention provides a real-time three-dimensional ultrasonic elastic imaging system, further comprising a region determination module for determining a region of interest;

[0086] There are two ways to determine the area of ​​interest:

[0087] Manual determination method, the user manually selects the region of interest based on the grayscale image;

[0088] Automatic outlining mode, based on the analysis of grayscale images, automatically selects the region of interest, including:

[0089] A processing unit, used to determine an initial detection area based on medical diagnosis requirements, and perform preliminary processing on the initial detection area to obtain image features;

[0090] A division unit, used for dividing the initial detection area based on image features to obtain multiple detection areas;

[0091] The selection unit is used to select a detection area whose feature difference between an image feature and a preset image feature is within a preset range as a region of interest.

[0092] The beneficial effect of the above design is to provide an accurate regional basis for subsequent real-time three-dimensional ultrasonic elastic imaging and a basis for ultimately viewing the characteristics of the lesion.

[0093] Embodiment 3:

[0094] Based on Example 1, the embodiment of the present invention provides a real-time three-dimensional ultrasonic elastic imaging system, wherein the shear wave excitation module includes:

[0095] The excitation unit is used to perform long pulse excitation on each array element row in the row-column addressing array, and the generated wave is focused on different emission focal points of the row-column addressing array, thereby generating shear waves propagating in the target area.

[0096] The beneficial effect of the above design is: by exciting transversely propagating shear waves at the depth of all emission foci, detection is carried out towards the area of ​​interest, wherein the transversely propagating shear waves excited at the depth of all emission foci form a shear wave plane, thereby ensuring the uniformity and accuracy of the obtained shear waves.

[0097] Embodiment 4:

[0098] Based on Example 1, the embodiment of the present invention provides a real-time three-dimensional ultrasonic elastic imaging system, wherein the shear wave excitation module is used to control the row and column addressing array probe to perform ultrasonic pulse excitation on the region of interest, including:

[0099] The transmitting unit is used for applying characteristic delayed ultrasonic pulse excitation to the array element after the row and column addressing array probe generates shear waves in the area of ​​interest, so as to generate focused or unfocused ultrasonic waves at different angles.

[0100] The acquisition module comprises:

[0101] A signal acquisition unit, used for acquiring ultrasonic echo signals of ultrasonic waves in a region of interest;

[0102] The conversion unit is used to convert the ultrasonic echo signal into a digital echo signal based on an analog-to-digital converter.

[0103] The beneficial effects of the above-mentioned design scheme are: according to the excitation direction and the number of excitation pulses, the row array elements of the row-column addressing array are used to perform pulse excitation on the area of ​​interest for generating three-dimensional shear waves to obtain ultrasonic waves, with fast imaging speed and real-time imaging, providing a basis for the observation of lesions, and the column array elements of the row-column addressing array are used to collect ultrasonic echo signals, and the echo signals are converted into digital signals based on analog-to-digital conversion, providing a signal basis for subsequent three-dimensional ultrasonic elastic imaging.

[0104] Embodiment 5:

[0105] Based on Example 1, the present invention provides a real-time three-dimensional ultrasound elastic imaging system, wherein the beamforming module includes:

[0106] The time calculation unit is used to calculate the total propagation time of the ultrasonic wave from the time t when the transmit beam is emitted to the time when the sound wave propagates to point P and is then received by the kth array element in the receiving array according to the following formula:

[0107]

[0108] in, represents the propagation time, Represents the vertical distance from the target point P to the center line of the transmitting aperture, represents the vertical distance from the target point P to the kth receiving array element, and c represents the propagation speed of the ultrasonic echo signal in the area of ​​interest;

[0109] The synthesis unit is used to calculate the reconstructed echo signal at the target point P according to the following formula ;

[0110]

[0111] Where w(k) is the weight coefficient, N represents the number of receiving array elements involved in the reconstruction calculation, represents the echo signal collected by the kth receiving element at time t;

[0112] A three-dimensional data frame sequence is obtained based on the echo signal reconstructed at the target point P;

[0113] In this embodiment, the transmit aperture centerline is the straight line where the transmit beam center plane intersects the RCA probe surface.

[0114] The imaging module comprises:

[0115] A calculation unit, used to obtain frame signals of a three-dimensional data frame sequence, and calculate a velocity distribution of the three-dimensional data frame sequence based on relative positions and time intervals between adjacent frame signals;

[0116] The calculation unit is further used to calculate the three-dimensional elastic image at time t according to the following formula based on the speed of the three-dimensional data frame sequence at time t;

[0117] E(t) = 3ρ‧c(t)^2

[0118] Where ρ is the tissue density of the region of interest, c(t) represents the three-dimensional distribution of shear wave velocity in the target area at time t;

[0119] A composite processing unit, used for composite processing of three adjacent frame signals based on the following formula to obtain a three-dimensional elastic distribution at time t;

[0120]

[0121] in, represents the weighted three-dimensional elastic image, E(t) represents the three-dimensional elastic image at time t, dt is the time interval between the generation of two three-dimensional elastic images, E(t-dt) and E(t-2*dt) are the three-dimensional elastic distributions at time t-dt and t-2*dt respectively, w1 represents the first weight coefficient, w2 represents the second weight coefficient, and w3 represents the third weight coefficient;

[0122] The imaging unit is used to obtain the three-dimensional elastic distribution based on the three-dimensional elastic characteristics at all times, and to perform three-dimensional imaging using a preset visualization method to obtain a three-dimensional ultrasonic elastic image.

[0123] In this embodiment, the three preset visualization modes include surface reconstruction, maximum / minimum projection, orthogonal slice visualization, parallel slice visualization, and the like.

[0124] The beneficial effects of the above design scheme are: through direct three-dimensional imaging, the deformation and distortion of three-dimensional target elastic imaging are reduced, the calculation complexity is reduced, and it is ensured that the three-dimensional ultrasonic elastic image can accurately and comprehensively display the characteristics of the lesion.

[0125] Embodiment 6:

[0126] Based on Example 1, a method for real-time three-dimensional ultrasonic elastic imaging system includes:

[0127] S1: Based on the row-column addressing array probe, long pulse excitation is performed on the region of interest to generate shear waves in the region of interest. It is also used to control the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest.

[0128] S2: collecting ultrasonic echo signals generated by ultrasonic pulse excitation in the region of interest, and converting the ultrasonic echo signals into digital echo signals;

[0129] S3: Performing beamforming reconstruction based on the digital echo signal to obtain a three-dimensional data frame sequence;

[0130] S4: Based on the three-dimensional data frame sequence, the velocity distribution of the shear wave in the region of interest is obtained, the three-dimensional elastic distribution is determined based on the velocity distribution, and the three-dimensional ultrasonic elastic image is obtained based on the three-dimensional elastic distribution.

[0131] The beneficial effects of the above-mentioned design scheme are as follows: by using row-column addressed probes for three-dimensional imaging, the number of probe array elements is relatively low, which can be realized by conventional ultrasound systems and has relatively low costs; by using row-column addressed probes for three-dimensional elastic imaging, the amount of data processed is relatively small, the complexity of the three-dimensional reconstruction algorithm is relatively low and easy to implement; a method of sequentially exciting multiple pulses is used to generate shear waves that propagate in three dimensions, and the propagation coverage range is large and the wavefront is approximately plane, which is beneficial to improving the accuracy of elastic calculations; specifically, based on the row-column addressed array probe, a long pulse is excited on the region of interest to generate shear waves in the region of interest; based on the row-column addressed array probe, a one-pulse excitation is performed on the region of interest for generating three-dimensional shear waves to generate ultrasonic waves in the region of interest, and the echo signals of the collected ultrasonic waves are converted into digital signals; beam synthesis reconstruction is performed based on the echo signals to obtain a three-dimensional data frame sequence; based on the three-dimensional data frame sequence, the velocity distribution of the shear wave in the region of interest is obtained, and based on the velocity distribution, a three-dimensional ultrasonic elastic image is obtained, and through direct three-dimensional imaging, the deformation and distortion of the three-dimensional target elastic imaging are reduced, the computational complexity is reduced, and it is ensured that the obtained three-dimensional ultrasonic elastic image can accurately and comprehensively display the characteristics of the lesion.

[0132] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention belong to the scope of this application document and its equivalent technology, the present invention is also intended to include these changes and variations.

Claims

1. A real-time three-dimensional ultrasonic elastic imaging system, characterized in that: include: An excitation module, used for performing long pulse excitation on the region of interest based on a row-column addressing array probe to generate shear waves in the region of interest, and also used for controlling the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest; An acquisition module is used to acquire ultrasonic echo signals generated by ultrasonic pulse excitation in the region of interest and convert the ultrasonic echo signals into digital echo signals; A beamforming module, used for performing beamforming reconstruction based on the digital echo signal to obtain a three-dimensional data frame sequence; An imaging module, for obtaining a velocity distribution of shear waves in a region of interest based on a three-dimensional data frame sequence, determining a three-dimensional elastic distribution based on the velocity distribution, and obtaining a three-dimensional ultrasonic elastic image based on the three-dimensional elastic distribution; The beamforming module comprises: The time calculation unit is used to calculate the total propagation time of the ultrasonic wave from the time t when the transmit beam is emitted to the time when the sound wave propagates to point P and is then received by the kth array element in the receiving array according to the following formula: Among them, t TOF (k,P) represents the propagation time, r tx Represents the vertical distance from the target point P to the center line of the transmitting aperture, r r (k) represents the vertical distance from the target point P to the kth receiving array element, and c represents the propagation speed of the ultrasonic echo signal in the region of interest; A synthesis unit, used to calculate the echo signal A(P) reconstructed at the target point P according to the following formula; Where w(k) is the weight coefficient, N is the number of receiving array elements involved in the reconstruction calculation, S(t TOF (k,P),k) represents the echo signal collected by the kth receiving element at time t; A three-dimensional data frame sequence is obtained based on the echo signal reconstructed at the target point P.

2. A real-time three-dimensional ultrasonic elastography system according to claim 1, characterized in that: Also included is a region determination module, for determining a region of interest; There are two ways to determine the area of ​​interest: Manual determination method, the user manually selects the region of interest based on the grayscale image; Automatic outlining mode, based on the analysis of grayscale images, automatically selects the region of interest, including: A processing unit, used to determine an initial detection area based on medical diagnosis requirements, and perform preliminary processing on the initial detection area to obtain image features; A division unit, used for dividing the initial detection area based on image features to obtain multiple detection areas; The selection unit is used to select a detection area whose feature difference between an image feature and a preset image feature is within a preset range as a region of interest.

3. The real-time three-dimensional ultrasonic elastography system according to claim 1, characterized in that: The incentive module comprises: The excitation unit is used to perform long pulse excitation on each array element row in the row-column addressing array, and the generated wave is focused on different emission focal points of the row-column addressing array, thereby generating shear waves propagating in the target area.

4. The real-time three-dimensional ultrasonic elastography system according to claim 1, characterized in that: The excitation module is used to control the row and column addressing array probe to perform ultrasonic pulse excitation on the region of interest, and includes: The transmitting unit is used for applying characteristic delayed ultrasonic pulse excitation to the array element after the row and column addressing array probe generates shear waves in the area of ​​interest, so as to generate focused or unfocused ultrasonic waves at different angles.

5. A real-time three-dimensional ultrasonic elastography system according to claim 4, characterized in that: The acquisition module comprises: A signal acquisition unit, used for acquiring ultrasonic echo signals of ultrasonic waves in a region of interest; The conversion unit is used to convert the ultrasonic echo signal into a digital echo signal based on an analog-to-digital converter.

6. The real-time three-dimensional ultrasonic elastography system according to claim 1, characterized in that: The imaging module comprises: A calculation unit, used to obtain frame signals of a three-dimensional data frame sequence, and calculate a velocity distribution of the three-dimensional data frame sequence based on relative positions and time intervals between adjacent frame signals; The calculation unit is further used to calculate the three-dimensional elastic image at time t according to the following formula based on the speed of the three-dimensional data frame sequence at time t; E(t)=3ρ·c(t)^2 Where ρ is the tissue density of the region of interest, c(t) represents the three-dimensional distribution of shear wave velocity in the target area at time t; A composite processing unit, used for composite processing of three adjacent frame signals based on the following formula to obtain a three-dimensional elastic distribution at time t; E out (t)=w1*E(t)+w2*E(t-dt)+w3*E(t-2*dt) Among them, E out (t) represents the weighted three-dimensional elastic image, E(t) represents the three-dimensional elastic image at time t, dt is the time interval between the generation of two three-dimensional elastic images, E(t-dt) and E(t-2*dt) are the three-dimensional elastic distributions at time t-dt and t-2*dt respectively, w1 represents the first weight coefficient, w2 represents the second weight coefficient, and w3 represents the third weight coefficient; The imaging unit is used to obtain the three-dimensional elastic distribution based on the three-dimensional elastic characteristics at all times, and to perform three-dimensional imaging using a preset visualization method to obtain a three-dimensional ultrasonic elastic image.

7. The method of a real-time three-dimensional ultrasonic elastography system according to claim 1, characterized in that: include: S1: Based on the row-column addressing array probe, long pulse excitation is performed on the region of interest to generate shear waves in the region of interest. It is also used to control the row-column addressing array probe to perform ultrasonic pulse excitation on the region of interest. S2: collecting ultrasonic echo signals generated by ultrasonic pulse excitation in the region of interest, and converting the ultrasonic echo signals into digital echo signals; S3: Performing beamforming reconstruction based on the digital echo signal to obtain a three-dimensional data frame sequence; S4: Based on the three-dimensional data frame sequence, the velocity distribution of the shear wave in the region of interest is obtained, the three-dimensional elastic distribution is determined based on the velocity distribution, and the three-dimensional ultrasonic elastic image is obtained based on the three-dimensional elastic distribution.

Images