A method, device and storage medium for eliminating interference in ultrasonic thermal imaging images

Abstract

The present application provides a method, device and storage medium for eliminating interference in ultrasonic thermal imaging images. The method for eliminating interference in ultrasonic thermal imaging images includes: collecting ultrasonic echo data during the heating process of the tissue to be treated with heat therapy; obtaining the original ultrasonic thermal imaging image of the tissue to be treated with heat therapy based on the ultrasonic echo data; determining the heat source center of the ablation needle in the original ultrasonic thermal image; performing data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain a reconstructed image of the ultrasonic thermal imaging image, wherein the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with the interference of the ablation needle area and the water vapor area eliminated. The present application eliminates the interference of the ablation needle area and the water vapor area in the original ultrasonic thermal imaging image by determining the position of the heat source center, thereby improving the safety of high-temperature ablation surgery.

Description

Technical Field

[0001] The present application relates to the technical field of ultrasonic thermal imaging images, and in particular to a method, device and storage medium for eliminating interference in ultrasonic thermal imaging images. Background Art

[0002] Existing thermal therapy surgeries are not safe in practice because doctors lack truly useful auxiliary images. For example, high-temperature tumor ablation surgery using microwaves and other means has improved the disadvantage of large surgical wounds, but insufficient ablation will cause residual cancer cells, and excessive ablation will risk damaging healthy organs. Ultrasonic thermal imaging technology, which can achieve non-destructive testing, is currently the most promising real-time in vivo thermal imaging technology.

[0003] Although ultrasound thermal imaging technology can monitor the temperature field of the lesion area in the body in real time, there will be a lot of ultrasound echo interference during its monitoring process. The most typical ones are the high echo of the physical ablation needle and the high echo of the "white fog"-like water vapor area caused by the evaporation and autonomous diffusion of water in the tissue after reaching high temperature (about 60°C). Unless high-power focused ultrasound therapy (HIFU) is used, commonly used microwave, radio frequency, and laser ablation must use a physical ablation needle. The physical ablation needle will more or less leave a high-echo area at the lesion location, and because water vapor will flexibly penetrate through the gaps in the tissue, the penetration area is irregular. The physical ablation needle and water vapor will cause the corresponding area to be unable to achieve thermal imaging or the imaging will be incomplete and unclear, causing the doctor to misjudge the ablation center and grasp the area, thereby affecting the high-temperature ablation operation. Summary of the invention

[0004] The purpose of the present application is to overcome the defect that the existing physical ablation needle and water vapor may cause the corresponding area to be unable to achieve thermal imaging or the imaging is incomplete and unclear, thereby affecting the performance of high-temperature ablation surgery.

[0005] To this end, the present application provides a method for eliminating interference in an ultrasonic thermal imaging image, which comprises:

[0006] Collecting ultrasonic echo data during the heating process of the tissue to be treated with thermal therapy;

[0007] Acquire the original ultrasonic thermal imaging image of the tissue to be treated with thermal therapy according to the ultrasonic echo data;

[0008] Determine the heat source center of the ablation needle in the original ultrasound thermal image;

[0009] The data of the original ultrasonic thermal imaging image is fitted based on the center of the heat source to obtain a reconstructed image of the ultrasonic thermal imaging image, wherein the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with interference from the ablation needle area and the water vapor area eliminated.

[0010] Furthermore, when the ablation needle is perpendicular to the ultrasound imaging plane of the tissue to be thermally treated, the circular high echo position in the ultrasound echo data is the position of the heat source center;

[0011] When the ablation needle is within the ultrasonic imaging plane of the tissue to be thermally treated, the hottest mark point on the ablation needle is the position of the center of the heat source.

[0012] Furthermore, the ultrasonic echo data is a radio frequency data sequence and a brightness data sequence of a two-dimensional ultrasonic image.

[0013] Furthermore, the data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain a reconstructed image of the ultrasonic thermal imaging image includes:

[0014] The interference of the ablation needle area is eliminated in the original ultrasound thermography image based on the center of the heat source.

[0015] Furthermore, the data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain a reconstructed image of the ultrasonic thermal imaging image includes:

[0016] Eliminate the interference of the ablation needle area in the original ultrasound thermal imaging image based on the center of the heat source;

[0017] Eliminate the interference of water vapor area in the original ultrasonic thermal imaging image based on the center of the heat source.

[0018] Furthermore, the method of eliminating interference of the ablation needle area in the original ultrasonic thermal imaging image based on the heat source center includes:

[0019] The original ultrasonic thermal strain image is smoothed by a low-pass filter;

[0020] Select the lateral invalid area of ​​the smoothed ultrasonic thermal strain image and delete the image data between the invalid areas;

[0021] One-dimensional Gaussian function fitting is performed to achieve lateral reconstruction of the ultrasonic thermal strain image after deleting the image data between the invalid regions;

[0022] Performing hyperbolic tangent function fitting to achieve axial reconstruction of ultrasonic thermal strain images after lateral reconstruction;

[0023] The ultrasonic thermal strain image after axial reconstruction is calculated to obtain the ultrasonic thermal imaging image with the interference of the ablation needle area eliminated.

[0024] Furthermore, the data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain the reconstructed image of the ultrasonic thermal imaging image also includes:

[0025] Eliminate the interference of water vapor area in the original ultrasonic thermal imaging image based on the center of the heat source;

[0026] The method of eliminating the interference of the water vapor area in the original ultrasonic thermal imaging image based on the heat source center includes:

[0027] determining an axis of symmetry in the original ultrasound thermographic image;

[0028] In the original ultrasonic thermal imaging image, the thermal imaging image of the normal area is mirror-imaged to the water vapor interference area on the other side of the symmetry axis;

[0029] Selecting invalid areas in the mirror-symmetrical ultrasonic thermal imaging image and deleting image data between the invalid areas;

[0030] Function fitting is performed to achieve image reconstruction of the ultrasonic thermal imaging image after deleting the invalid area, thereby obtaining an ultrasonic thermal imaging image with the interference of the water vapor area eliminated.

[0031] The present application also provides a device for eliminating interference in ultrasonic imaging, comprising:

[0032] A data acquisition module, which is used to collect ultrasonic echo data during the heating process of the tissue to be treated with thermal therapy;

[0033] An acquisition module, which is used to acquire an original ultrasonic thermal imaging image of the tissue to be thermally treated according to the ultrasonic echo data, and the acquisition module is also used to determine the heat source center of the ablation needle in the original ultrasonic thermal image;

[0034] An image reconstruction module is used to perform data fitting of the original ultrasonic thermal imaging image based on the center of the heat source to obtain a reconstructed image of the ultrasonic thermal imaging image, wherein the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with the interference of the ablation needle area and the water vapor area eliminated.

[0035] The present application also provides a device for eliminating interference in ultrasonic imaging, including a processor and a memory, wherein the memory stores a computer program, and when the processor executes the computer program, the aforementioned method for eliminating interference in ultrasonic imaging is implemented.

[0036] The present application also provides a storage medium, on which a program is stored. When the program is executed by a processor, it is used to implement the aforementioned method for eliminating interference in ultrasonic imaging.

[0037] The present application completes the reconstruction of the ultrasonic thermal imaging image by determining the position of the heat source center to eliminate the interference of the ablation needle area and the water vapor area in the original ultrasonic thermal imaging image, and finally realizes the display of reasonable and complete ultrasonic temperature monitoring effects, reduces the interference of the ablation needle and the water vapor area on the high-temperature ablation surgery, and improves the safety of the high-temperature ablation surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 is a flow chart of a method for eliminating interference in an ultrasonic thermal imaging image;

[0040] Figure 2 2D ultrasound images of the tissue to be heated in ultrasound B mode according to time changes, wherein (a)-(f) correspond to the 2D ultrasound images of the tissue to be heated at the 0th to 5th minute respectively;

[0041] Figure 3 is the original ultrasonic thermal strain image sequence, where Figure 3 (a)-(f) are the original ultrasonic thermal strain images calculated based on the one-to-one correspondence of the ultrasonic radio frequency data at the same time;

[0042] Figure 4 is the original ultrasonic thermal imaging image sequence, where Figure 4 (a)-(f) are based on Figure 3 (a)-(f) The original ultrasonic thermal imaging images calculated one by one;

[0043] Figure 5 This is a schematic diagram of the hottest landmark point of the ablation needle;

[0044] Figure 6 (a) is the original ultrasonic thermal strain image with only the ablation needle interference area. Figure 6 (b) is the ultrasonic thermal strain image after low-pass filter processing. Figure 6 (c) is the ultrasonic thermal strain image after deleting the invalid area image data. Figure 6 (d) is the ultrasonic thermal strain image after one-dimensional Gaussian function fitting. Figure 6 (e) is the ultrasonic thermal strain image after axial reconstruction. Figure 6 (f) is an ultrasound thermal imaging image in which the interference of the ablation needle area is eliminated by ultrasound;

[0045] Figure 7 (a) is a verification diagram of the accuracy of the fitting results of the ultrasonic thermal strain image after one-dimensional Gaussian function fitting. Figure 7 (b) is a verification diagram of the accuracy of the fitting effect of the ultrasonic thermal strain image after axial reconstruction;

[0046] Figure 8 (a) is the original ultrasonic thermal imaging image. Figure 8(b) is the ultrasonic thermal imaging image of the water vapor interference area on the other side of the symmetry axis, which is a mirror image of the thermal imaging image of the normal area. Figure 8 (c) is the ultrasonic thermal imaging image after deleting the image data of the invalid area. Figure 8 (d) is an ultrasonic thermal imaging image with the interference of water vapor area eliminated;

[0047] Fig. 9 Device for eliminating interference in ultrasound imaging;

[0048] Fig.10 A device for eliminating interference in ultrasound imaging. DETAILED DESCRIPTION

[0049] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0050] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0051] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0053] Example 1

[0054] Embodiment 1 provides a method for eliminating interference in an ultrasonic thermal imaging image. Figure 1is a flow chart of a method for eliminating interference in ultrasonic thermal imaging images, referring to Figure 1 , the method of eliminating interference in ultrasonic thermal imaging images includes:

[0055] S1, collecting ultrasonic echo data during the heating process of the tissue to be treated with thermal therapy;

[0056] Specifically, the ultrasonic echo data is a radio frequency data sequence and a brightness data sequence of a two-dimensional ultrasonic image;

[0057] A thermal therapy device with a physical ablation needle (for example, a microwave ablation device with a power of 10 W) is used to continuously heat the simulated lesion target area. The simulated lesion target area is the tissue to be treated with thermal therapy. The lesion target area can be a lesion at a depth of 2 cm in the pig liver. A medical ultrasound instrument is connected to an ultrasound probe to collect ultrasonic echo data of the tissue to be treated with thermal therapy, and the RF radio frequency data sequence Ru (u=0, 1, 2, 3, 4, 5) and B brightness data sequence Bu (u=0, 1, 2, 3, 4, 5) of the two-dimensional digital ultrasound image are obtained.

[0058] The RF radio frequency data sequence Ru (u = 0, 1, 2, 3, 4, 5) and the B brightness data sequence Bu (u = 0, 1, 2, 3, 4, 5) of the two-dimensional digital ultrasound image are shown in Figure 2 , Figure 2 The two-dimensional ultrasound images of the tissue to be heated in ultrasound B mode according to time changes. (a)-(f) correspond to the heating time of 0-5 minutes respectively. The solid line frame is the interference area of ​​the ablation needle tip, and the dotted line frame is the water vapor interference area. Figure 2 From (b) to (f), we can see that there is always a long strip area directly below the ablation needle, which is the interference area of ​​the ablation needle tip. Its brightness value is much weaker than that of the surrounding normal area. Figure 2 In (d)-(f), it can be seen that as the heating time increases, the rectangular area that begins to appear and expands directly below the ablation needle is the water vapor interference area, and its brightness value is weaker and more chaotic than other normal areas.

[0059] S2, acquiring an original ultrasonic thermal imaging image of the tissue to be thermally treated according to the ultrasonic echo data;

[0060] Specifically, the step of acquiring the original ultrasonic thermal imaging image of the tissue to be thermally treated according to the ultrasonic echo data includes:

[0061] S21, calculating and obtaining an original ultrasonic thermal strain image based on the radio frequency data sequence;

[0062] Specifically, the original ultrasonic thermal strain image is obtained from the radio frequency data by using the model principle of thermal strain imaging. Specifically, the axial local displacement of the two-dimensional sliding window is calculated for the radio frequency data sequence Ru of the two-dimensional ultrasonic image and the initial image R0 (the image when u=0), and the original ultrasonic thermal strain image Lu is obtained. Figure 3 is the original ultrasonic thermal strain image sequence, Figure 3 (a)-(f) are the original ultrasonic thermal strain images calculated based on the one-to-one correspondence of the ultrasonic radio frequency data at the same time in the figure.

[0063] Figure 3 (a)-(c) correspond to the first 3 minutes of the tissue being heated, when the temperature is relatively low and water vapor has not yet been generated. Figure 3 From (b) to (f), we can see that there is a long strip area below the ablation needle, which is the needle tip interference area. Its thermal strain value is much weaker than that of the surrounding normal area. Figure 3 (d)-(f) correspond to 3 minutes after the heating experiment. As the temperature rises, a high-echo area of ​​water vapor is generated and gradually spreads to both sides of the picture, especially to the left side. Therefore, it can be clearly seen that in addition to the original long strip area, water vapor interference areas appear on both sides. The thermal strain value of the water vapor interference area is much weaker than that of the surrounding normal area and is more chaotic.

[0064] S22. Calculate and obtain an original ultrasonic thermal imaging image based on the original ultrasonic thermal strain image.

[0065] Specifically, the axial gradient is calculated using the original ultrasonic thermal strain image Lu, and the original ultrasonic thermal imaging image Tu is obtained by combining the parameter conversion. The formula used is:

[0066]

[0067] Where T u (z) is the temperature at depth z, c0 is the initial sound velocity in the tissue, α is the tissue expansion coefficient, β is the sound velocity variation coefficient, and T0 is the initial temperature of the tissue before heating. Figure 4 is the original ultrasonic thermal imaging image sequence, Figure 4 (a)-(f) are based on Figure 3 (a)-(f) are the original ultrasonic thermal imaging images calculated one by one. Figure 4 , Figure 4 The original ultrasound thermal imaging images in (b)-(c) lack thermal imaging images only in the interference area of ​​the ablation needle tip. Figure 4 The original ultrasonic thermal imaging images in (d)-(f) lack thermal imaging images in both the needle tip interference area and the water vapor interference area, that is, they can only display about half of the actual temperature rise space range.

[0068] S3, determining the heat source center of the ablation needle in the original ultrasound thermal image;

[0069] Specifically, there are two common directions for ablation needle insertion. One is perpendicular to the ultrasound imaging plane of the tissue to be heated, and the other is that the ablation needle is inserted into the epidermis of the tissue to be heated at an angle, with an acute angle between the ablation needle and the horizontal line of the ultrasound imaging plane of the tissue to be heated. When the ablation needle has an acute angle with the horizontal line of the ultrasound imaging plane of the tissue to be heated, the ablation needle is in the ultrasound imaging plane of the tissue to be heated.

[0070] When the ablation needle is perpendicular to the ultrasound imaging plane of the tissue to be heated, the circular high-echo position in the ultrasound echo data is the position of the heat source center; when the ablation needle is in the ultrasound imaging plane of the tissue to be heated, the hottest mark on the ablation needle is the position of the heat source center. Specifically, when the ablation needle is in the ultrasound imaging plane of the tissue to be heated, the end of the high-echo bright line in the ultrasound echo data is the needle tip of the ablation needle. Figure 5 This is a schematic diagram of the hottest landmark of the ablation needle. Figure 5 The hottest landmark point is the one cm away from the ablation needle tip.

[0071] S4. Perform data fitting of the original ultrasonic thermal imaging image based on the center of the heat source to obtain a reconstructed image of the ultrasonic thermal imaging image, wherein the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with interference from the ablation needle area and the water vapor area eliminated.

[0072] Specifically, the interference area of ​​the ablation needle is mainly the interference area of ​​the needle tip of the ablation needle. When water vapor is not generated in the low-temperature stage (i.e., the early stage of heating), it is only necessary to eliminate the interference of the ablation needle tip area in the original ultrasonic thermal imaging image. When water vapor is generated, it is necessary to eliminate the interference of the ablation needle tip area in the original ultrasonic thermal imaging image and then further eliminate the interference of the water vapor area in the original ultrasonic thermal imaging image.

[0073] Furthermore, the data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain a reconstructed image of the ultrasonic thermal imaging image includes:

[0074] S41. Eliminate interference of the ablation needle area in the original ultrasound thermal imaging image based on the center of the heat source.

[0075] Specifically, when there is only a needle tip interference area in the original ultrasound thermal imaging image, the interference area is small, and it is OK to select the original ultrasound thermal strain imaging node to eliminate the needle tip interference or the original ultrasound thermal imaging image to eliminate the needle tip area interference. Since the proportion of the original ultrasound thermal strain image is significantly greater than the proportion of the original ultrasound thermal imaging image at the same time, the original ultrasound thermal strain image is preferentially selected as the node for eliminating interference. Eliminating the interference of the ablation needle area in the original ultrasound thermal imaging image based on the heat source center includes:

[0076] S411, smoothing the original ultrasonic thermal strain image through a low-pass filter;

[0077] Figure 6 (a) is the original ultrasonic thermal strain image with only the ablation needle interference area. Figure 6 (a) is taken as an example, and a low-pass filter (such as a Savitzky-Golay filter) is used to process Figure 6 (a), ultrasonic thermal strain image smL after low-pass filter processing u (z,x)( Figure 6 (b)), Figure 6 (b) is the ultrasonic thermal strain image after low-pass filter processing.

[0078] S412, selecting the lateral invalid area of ​​the smoothed ultrasonic thermal strain image, and deleting the image data between the invalid areas;

[0079] Specifically, in Figure 6 (b) The horizontal (x direction) data lines smL at each depth z(i) are taken out from shallow to deep. u (z(i),x), find the two highest signal peak positions x1 and x2, select the area between the highest signal peak positions at each depth as the lateral invalid area of ​​the smoothed ultrasonic thermal strain image, delete the image data between the invalid areas to obtain Figure 6 (c) Figure 6 (c) is the ultrasonic thermal strain image after deleting the invalid area image data.

[0080] S413, performing one-dimensional Gaussian function fitting to achieve lateral reconstruction of the ultrasonic thermal strain image after deleting the image data between the invalid regions;

[0081] Specifically, for the ultrasonic thermal strain image after deleting the invalid area image data, in the area near the heat source center, smL u The remaining data of (z(i),x) are fitted with a one-dimensional Gaussian function to achieve the lateral reconstruction of the ultrasonic thermal strain image after deleting the image data between the invalid areas. The area near the heat source center is defined based on the center of the rectangular area with the heat source center as the center, and smL is defined. u >σ(smL u ), σ represents the standard deviation, and the ultrasonic thermal strain image after one-dimensional Gaussian function fitting is shown in Figure 6 (d) Figure 6 (d) is the ultrasonic thermal strain image after one-dimensional Gaussian function fitting. Figure 7 (a) is a verification diagram of the accuracy of the fitting results of the ultrasonic thermal strain image after one-dimensional Gaussian function fitting. Figure 7In (a), data is the image data after deleting the invalid area, and fit is the fitting line. Figure 7 (a) It can be seen that the ultrasonic thermal strain image obtained after fitting with the one-dimensional Gaussian function is accurate.

[0082] S414, performing hyperbolic tangent function fitting to achieve axial reconstruction of the ultrasonic thermal strain image after the lateral reconstruction;

[0083] Specifically, for the ultrasonic thermal strain image after one-dimensional Gaussian function fitting, in the vicinity of the heat source center, from left to right, the data line xfitL of each lateral x(j) position is taken out in turn. u (z, x(j)), and the hyperbolic tangent function is fitted to obtain the ultrasonic thermal strain image after axial reconstruction Figure 6 (e) Figure 6 (e) is the ultrasonic thermal strain image after axial reconstruction. Figure 7 (b) is a verification diagram of the accuracy of the fitting effect of the ultrasonic thermal strain image after axial reconstruction. Figure 7 In (b), data is the image data, and fit is the fitting line. Figure 7 (b) It can be seen that the ultrasonic thermal strain image obtained after axial reconstruction is accurate.

[0084] S415 , calculating the ultrasonic thermal strain image after axial reconstruction to obtain an ultrasonic thermal imaging image with the interference of the ablation needle area eliminated.

[0085] Specifically, the ultrasonic thermal strain image after axial reconstruction is calculated according to the thermal strain principle to obtain an ultrasonic thermal imaging image that eliminates the interference of the ablation needle area. Figure 6 (f) is an ultrasound thermal imaging image in which the interference of the ablation needle area is eliminated.

[0086] Furthermore, the data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain the reconstructed image of the ultrasonic thermal imaging image also includes:

[0087] S42, eliminating interference of water vapor area in the original ultrasonic thermal imaging image based on the center of the heat source;

[0088] Specifically, when water vapor is generated, it is necessary to eliminate the water vapor interference after eliminating the interference in the ablation needle area. The method for eliminating the interference in the ablation needle area can be based on the above method when the interference in the water vapor area is not generated. The interference in the water vapor area is eliminated in the original ultrasonic thermal imaging image based on the center of the heat source, including:

[0089] S421, determining a symmetry axis in the original ultrasonic thermal imaging image;

[0090] Specifically, since the lesions to be ablated and scanned are generally uniform isotropic tissues, according to the principle of heat conduction, the distribution of the temperature field around the ablation needle is spatially symmetrical. Therefore, the symmetry axis is first determined in the original ultrasonic thermal imaging image. For the case where the ablation needle is perpendicular to the ultrasonic imaging plane of the tissue to be heat treated, the horizontal line of the depth position Z of the heat source center is used as the symmetry axis. For the case where the ablation needle is on the ultrasonic imaging plane of the tissue to be heat treated, the oblique line where the ablation needle itself is located is used as the symmetry axis.

[0091] S422, mirroring the thermal imaging image of the normal area in the original ultrasonic thermal imaging image to the water vapor interference area on the other side of the symmetry axis;

[0092] Specifically, Figure 8 (a) is the original ultrasonic thermal imaging image. Figure 8 (a) as an example. After the symmetry axis is determined, according to the spatial symmetry principle of ultrasonic thermal imaging images, the normal area of ​​the original ultrasonic thermal imaging image is mirrored to the water vapor interference area on the other side of the symmetry axis. The symmetric image is shown in Figure 8 (b) Figure 8 (b) is an ultrasonic thermal imaging image of the water vapor interference area that is mirrored to the other side of the symmetry axis.

[0093] S423, axially selecting an invalid area in the mirror-symmetric ultrasonic thermal imaging image, and deleting image data between the invalid areas;

[0094] Specifically, for the ultrasonic thermal imaging image of the normal area mirror-symmetric to the water vapor interference area on the other side of the symmetry axis, the invalid area is selected by referring to the method for eliminating the interference of the ablation needle, and the image data of the invalid area is deleted to obtain the ultrasonic thermal imaging image after deleting the image data between the invalid areas. Figure 8 (c) Figure 8 (c) is the ultrasonic thermal imaging image after deleting the image data of the invalid area.

[0095] S424, performing function fitting to achieve image reconstruction of the ultrasonic thermal imaging image after deleting the invalid area, to obtain an ultrasonic thermal imaging image with the interference of the water vapor area eliminated;

[0096] Specifically, for the ultrasonic thermal imaging image after deleting the image data of the invalid area, when the ablation needle is perpendicular to the ultrasonic imaging plane of the tissue to be treated with heat therapy, σ(z,x) (σ(z,x) is the standard deviation of the ultrasonic thermal imaging image of the two-dimensional full screen) is used as the threshold to extract the high-temperature, approximately elliptical area in the ultrasonic thermal imaging image after deleting the image data of the invalid area, and the ultrasonic thermal imaging image with the interference of the water vapor area eliminated is fitted using the two-dimensional normal distribution formula. The two-dimensional normal distribution formula is:

[0097]

[0098] In the formula, (μ X ,μ Y ) is the center position of the heat source, X and Y are the major and minor axes of the ellipse, respectively, ρ is the correlation coefficient between X and Y, (σ X ,σ Y ) are the standard deviations of the data in the major and minor axes of the ellipse, respectively.

[0099] Specifically, for the ultrasonic thermal imaging image after deleting the image data of the invalid area, when the ablation needle is in the ultrasonic imaging plane of the tissue to be treated with thermal therapy, the fitting steps are the same as when the ablation needle is perpendicular to the ultrasonic imaging plane of the tissue to be treated with thermal therapy. However, since the ablation needle is inserted obliquely into the tissue epidermis when the ablation needle is in the ultrasonic imaging plane of the tissue to be treated with thermal therapy, but the ultrasonic probe is attached to the tissue epidermis, the axes of the two-dimensional distribution during fitting are the ablation needle direction X' and the perpendicular ablation needle direction Y', and X' has an angle with the ultrasonic plane horizontal line X when the ablation needle is perpendicular to the ultrasonic imaging plane of the tissue to be treated with thermal therapy. The method for obtaining the angle θ is as follows:

[0100] Select the coordinates of n data points on the edge of the high-temperature zone points = [x1, y1, x2, y2, ..., xn, yn]; calculate the covariance matrix cov_matrix = cov(points) of the above coordinates; perform eigendecomposition of the covariance matrix [V, D] = eig(cov_matrix) to obtain the eigenvector, which is the angle θ. After obtaining the angle, first rotate the image data of the ultrasonic thermal imaging image after deleting the image data of the invalid area by θ degrees and then perform Gaussian function fitting, that is, use all the valid area data of the ultrasonic thermal imaging image after deleting the image data of the invalid area to perform two-dimensional Gaussian function fitting, and obtain the ultrasonic thermal imaging image with the interference of the water vapor area eliminated.

[0101] Specifically, Figure 8 (d) is the ultrasonic thermal imaging image after eliminating the interference of water vapor area.

[0102] The above-mentioned method for eliminating interference in ultrasonic thermal imaging images eliminates the interference of the ablation needle area and the water vapor area in the original ultrasonic thermal imaging image by determining the position of the heat source center, completes the reconstruction of the ultrasonic thermal imaging image, and finally realizes the display of reasonable and complete ultrasonic temperature monitoring effects, reduces the interference of the ablation needle and water vapor area on high-temperature ablation surgery, and improves the safety of high-temperature ablation surgery.

[0103] Example 2

[0104] Embodiment 2 provides a device for eliminating interference in ultrasonic imaging. Fig. 9 For a device to eliminate interference in ultrasound imaging, refer to Fig. 9The device for eliminating interference in ultrasonic imaging includes a data acquisition module, an acquisition module and an image reconstruction module which are interconnected. The data acquisition module is used to acquire ultrasonic echo data during the heating process of the tissue to be thermally treated. The acquisition module is used to acquire the original ultrasonic thermal imaging image of the tissue to be thermally treated according to the ultrasonic echo data, and the acquisition module is also used to determine the heat source center of the ablation needle in the original ultrasonic thermal image. The image reconstruction module is used to perform data fitting of the original ultrasonic thermal imaging image based on the heat source center to acquire a reconstructed image of the ultrasonic thermal imaging image, and the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with the interference of the ablation needle area and the water vapor area eliminated.

[0105] Example 3

[0106] Embodiment 3 provides a device for eliminating interference in ultrasonic imaging. Fig.10 The device for eliminating interference in ultrasound imaging includes a processor 910 and a memory 920 .

[0107] The processor 910 may include one or more processing cores. The processor 910 uses various interfaces and lines to connect various parts of the entire device, and executes various functions of the device and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory 920, and calling data stored in the memory 920. Optionally, the processor 910 can be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor 910 can integrate one or a combination of a central processing unit (CPU) and a modem. Among them, the CPU mainly processes the operating system and application programs; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor 910, but may be implemented separately through a chip.

[0108] Optionally, when the processor 910 executes the program instructions in the memory 320 , the method for eliminating interference in the ultrasonic thermal imaging image provided by the above method embodiment is implemented.

[0109] The memory 920 may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory 920 includes a non-transitory computer-readable storage medium. The memory 920 may be used to store instructions, programs, codes, code sets, or instruction sets. The memory 920 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function, instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data created according to the use of the device, etc.

[0110] Optionally, the present application also provides a storage medium, which stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement the method for eliminating interference in ultrasonic thermal imaging images provided by the above-mentioned method embodiment.

[0111] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A method for eliminating interference in an ultrasonic thermal imaging image, characterized in that: include: Collecting ultrasonic echo data during the heating process of the tissue to be treated with thermal therapy; Acquire the original ultrasonic thermal imaging image of the tissue to be treated with thermal therapy according to the ultrasonic echo data; Determine the heat source center of the ablation needle in the original ultrasound thermal image; The data of the original ultrasonic thermal imaging image is fitted based on the center of the heat source to obtain a reconstructed image of the ultrasonic thermal imaging image, wherein the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with interference from the ablation needle area and the water vapor area eliminated.

2. A method for eliminating interference in ultrasonic thermal imaging images according to claim 1, characterized in that: When the ablation needle is perpendicular to the ultrasound imaging plane of the tissue to be treated with heat therapy, the circular high echo position in the ultrasound echo data is the position of the heat source center; When the ablation needle is within the ultrasonic imaging plane of the tissue to be thermally treated, the hottest mark point on the ablation needle is the position of the center of the heat source.

3. A method for eliminating interference in ultrasonic thermal imaging images according to claim 1, characterized in that: The ultrasonic echo data is a radio frequency data sequence and a brightness data sequence of a two-dimensional ultrasonic image.

4. A method for eliminating interference in ultrasonic thermal imaging images according to claim 3, characterized in that: The method of acquiring the original ultrasonic thermal imaging image of the tissue to be thermally treated according to the ultrasonic echo data comprises: The original ultrasonic thermal strain image is calculated based on the radio frequency data sequence; The original ultrasonic thermal imaging image is calculated based on the original ultrasonic thermal strain image.

5. A method for eliminating interference in ultrasonic thermal imaging images according to claim 4, characterized in that: The method of performing data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain a reconstructed image of the ultrasonic thermal imaging image includes: The interference of the ablation needle area is eliminated in the original ultrasound thermography image based on the center of the heat source.

6. A method for eliminating interference in ultrasonic thermal imaging images according to claim 5, characterized in that: The method of eliminating interference of the ablation needle area in the original ultrasonic thermal imaging image based on the heat source center includes: The original ultrasonic thermal strain image is smoothed by a low-pass filter; Select the lateral invalid area of ​​the smoothed ultrasonic thermal strain image and delete the image data between the invalid areas; One-dimensional Gaussian function fitting is performed to achieve lateral reconstruction of the ultrasonic thermal strain image after deleting the image data between the invalid regions; Performing hyperbolic tangent function fitting to achieve axial reconstruction of ultrasonic thermal strain images after lateral reconstruction; The ultrasonic thermal strain image after axial reconstruction is calculated to obtain the ultrasonic thermal imaging image with the interference of the ablation needle area eliminated.

7. A method for eliminating interference in ultrasonic thermal imaging images according to claim 6, characterized in that: The method of performing data fitting of the original ultrasonic thermal imaging image based on the heat source center to obtain a reconstructed image of the ultrasonic thermal imaging image also includes: Eliminate the interference of water vapor area in the original ultrasonic thermal imaging image based on the center of the heat source; The method of eliminating the interference of the water vapor area in the original ultrasonic thermal imaging image based on the heat source center includes: determining an axis of symmetry in the original ultrasound thermographic image; In the original ultrasonic thermal imaging image, the thermal imaging image of the normal area is mirror-imaged to the water vapor interference area on the other side of the symmetry axis; Selecting invalid areas axially in the mirror-symmetric ultrasonic thermal imaging image, and deleting image data between the invalid areas; Function fitting is performed to achieve image reconstruction of the ultrasonic thermal imaging image after deleting the invalid area, thereby obtaining an ultrasonic thermal imaging image with the interference of the water vapor area eliminated.

8. A device for eliminating interference in ultrasonic imaging, characterized in that: include: A data acquisition module, which is used to collect ultrasonic echo data during the heating process of the tissue to be treated with thermal therapy; An acquisition module, which is used to acquire an original ultrasonic thermal imaging image of the tissue to be thermally treated according to the ultrasonic echo data, and the acquisition module is also used to determine the heat source center of the ablation needle in the original ultrasonic thermal image; An image reconstruction module is used to perform data fitting of the original ultrasonic thermal imaging image based on the center of the heat source to obtain a reconstructed image of the ultrasonic thermal imaging image, wherein the reconstructed image of the ultrasonic thermal imaging image is an image of the original ultrasonic thermal imaging image with the interference of the ablation needle area and the water vapor area eliminated.

9. A device for eliminating interference in ultrasonic imaging, characterized in that: The method comprises a processor and a memory, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A storage medium, characterized in that: The storage medium stores a program, and when the program is executed by the processor, it is used to implement the method described in any one of claims 1 to 7.

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