CN115736987A - Rapid imaging method for breast positioning of hemispherical ultrasonic tomography system - Google Patents

Abstract

The invention belongs to the field of ultrasonic tomography, and particularly relates to a quick imaging method for breast positioning of a hemispherical ultrasonic tomography system, which comprises the following steps: acquiring empty water data; breast data acquisition; analyzing the collected data; preprocessing the analyzed data; calculating an attenuation coefficient; carrying out image reconstruction; processing the reconstructed image, storing the processed image in a specified memory position, and periodically reading the processed image through a GUI (graphical user interface) terminal; and displaying the breast position images of the coronal plane and the sagittal plane through a GUI end, and judging whether the breast position of the patient is in the optimal area. The invention can image a pair of coronal planes and a pair of sagittal plane acoustic attenuation rate images in real time, can judge whether the breast in XY direction is in the optimal imaging area through the coronal plane, and can judge whether the patient in Z direction is deep enough through the sagittal plane.

Description

A fast imaging method for breast positioning in a hemispherical ultrasonic tomography system

technical field

The invention belongs to the field of ultrasonic tomography, in particular to a fast imaging method for breast positioning in a hemispherical ultrasonic tomography system.

Background technique

The imaging space of ultrasonic tomography is three-dimensional, but the optimal imaging area is generally smaller than the imaging aperture size. When the patient lies prone on the device, the naked eye cannot judge whether the breast is in the optimal imaging area. The existing optical camera method cannot accurately judge the position of the patient's breast and the imaging effect varies greatly.

The Chinese patent with the publication number CN113598825A discloses a breast positioning imaging method for an ultrasonic imaging system and its application. The solution includes the following steps: setting the sequence of ultrasonic transducer array elements, each of the ultrasonic transducers The array element transmits and collects ultrasonic signals according to the sequence; calculates and obtains the contour of the coronal surface of the first layer of the breast according to the collected ultrasonic signals; performs spatial coordinate conversion on the contour, and obtains the contour in the ultrasonic imaging system. Spatial distribution in the cross-section, the present invention has the advantages of high positioning accuracy and good imaging effect.

However, the above-mentioned breast localization imaging method still has the following disadvantages:

The contrast is poor, the noise is obvious, it is difficult to effectively identify the position of the breast, and there is only one section display (X, Y direction), and there is no depth direction information.

Contents of the invention

In order to make up for the deficiencies in the prior art, the present invention provides a technical proposal of a rapid imaging method for breast positioning in a hemispherical ultrasonic tomographic imaging system.

A fast imaging method for breast positioning of a hemispherical ultrasonic tomography system, comprising:

Step 1, empty water data collection;

Step 2, breast data collection;

Step 3, analyzing the collected data;

Step 4, preprocessing the parsed data;

Step 5, calculating the attenuation coefficient;

Step 6, carry out image reconstruction;

Step 7: Process the reconstructed image, store the processed image in a designated memory location, and periodically read it through the GUI terminal.

Further, in the step 1 and step 2, the data of the coronal plane and the sagittal plane are collected at the same time during each collection.

Further, said step 3 includes:

Correspond the transmitting TAS serial number, transmitting array element serial number, receiving TAS serial number, receiving array element serial number and an AScan, and store them in the memory.

Further, the step 3 includes: distinguishing the sagittal plane data and the coronal plane data, and using them for reconstruction of sagittal plane and coronal plane images respectively.

Further, said step 4 includes:

Step 4.1, calculate the energy of each AScan signal according to the following formula:

In the formula, L is the characteristic length of the transmitted signal, and t0 is the arrival time of the direct wave;

Step 4.2, LOR sorting, including: connecting all transmitting array elements and receiving array element pairs, finding the result of polar coordinate transformation of the Line in the original Cartesian coordinate system, and arranging the signals into (R, theta) matrix, R is The distance from the path to the center point, theta is the angle between the path and the coordinate axis, and the data of the sagittal plane and the coronal plane are separately sorted by LOR.

Further, said step 5 includes:

According to the energy I calculated in step 4, the sorted empty water and breast data are calculated according to the following formula:

Atten=log(I _{empty water} /I _object )

Wherein, Atten is the attenuation coefficient of each transmitting and receiving pair.

Further, said step 6 includes:

Reconstruct the processed Atten according to the following formula:

是第m个加权投影的衰减值，W_m+是第m个衰减对应的归一化因子，λ_k是第k次迭代的系数，

是整个成像系统的采样点，w_m’n是像素n和所有衰减相交距离之和，m'用来计算像素n和所有衰减相交距离的和，是一个常数的加权，可以提出去。Among them, f is the image, k is the number of iterations, n is the pixel number, w _mn is the intersection distance between the mth attenuation and the nth pixel, p _m is the mth attenuation value,

is the attenuation value of the mth weighted projection, W _m+ is the normalization factor corresponding to the mth attenuation, λ _k is the coefficient of the kth iteration,

is the sampling point of the entire imaging system, w _m'n is the sum of pixel n and all attenuation intersection distances, m' is used to calculate the sum of pixel n and all attenuation intersection distances, and is a constant weight, which can be proposed.

Further, said step 7 includes:

Step 7.1, mapping the reconstructed image value to the interval of 0-255;

Step 7.2, according to the theoretical optimal imaging area, add a rectangular mask to the reconstructed images of the sagittal plane and the coronal plane respectively, keep the images in the Mask, set the images other than the Mask to 0, and store the processed images in the designated memory The position is periodically read through the GUI.

Further, step 8 also includes: the GUI terminal displays the breast position images of the coronal plane and the sagittal plane respectively through two windows, so as to judge whether the patient's breast position is in the optimal area.

Compared with prior art, the beneficial effect of the present invention is:

The present invention can image a pair of coronal plane and a pair of sagittal plane sound attenuation rate maps in real time, judge whether the breast is in the best imaging area in the XY direction through the coronal plane, and judge whether the patient is prone in the Z direction through the sagittal plane Whether it is deep enough, the present invention is integrated on the GUI operation interface, and the image is displayed in the GUI in real time, which is convenient for operation and judging whether the position of the patient's breast is in the optimal area.

Description of drawings

Fig. 1 is the flow chart of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

The hemispherical support used in the present invention refers to the patent CN113598825A, and the serial numbers of the ultrasonic transducer array and the ultrasonic transducer array elements of the present invention are set according to the method in the patent CN113598825A.

Please refer to Fig. 1, a kind of hemispherical ultrasonic tomography system breast localization fast imaging method, comprises the following steps:

Step 1, air and water data collection

Empty water data collection is exactly to carry out data collection when only water has no object, and effect is to provide a benchmark for the present invention.

The selection of transmitting and receiving transducers follows the principle of geometric space position: select the TAS at the intersection of the tangent plane and the hemispherical transducer. Data in the coronal and sagittal planes are collected simultaneously for each acquisition.

Step 2, breast data collection

For data collection of the breast, the ultrasonic transducer and collection method used are the same as above.

Step 3, data analysis

The main purpose is to match the transmitting TAS serial number, transmitting array element serial number, receiving TAS serial number, receiving array element serial number and a section of AScan (4000 points), and store them in the memory. At the same time, this step distinguishes the sagittal plane and the coronal plane, which are used for reconstruction of the sagittal plane and coronal plane images respectively.

Step 4, data preprocessing

Step 4.1, calculate the energy of each AScan signal, and integrate according to the following formula:

Among them, L is the characteristic length of the transmitted signal, and t0 is the arrival time of the direct wave.

Step 4.2, LOR (Line of Response) reordering. This is done by reordering the signals according to their geometrical position. Connect all transmitting array elements and receiving array element pairs, find the polar coordinate transformation of the Line in the original direct coordinate system, and arrange the signals into an (R, theta) matrix. R is the distance from the path to the center point, and theta is the angle between the path and the coordinate axis. In this step, the data of the sagittal plane and the coronal plane need to be sorted separately for LOR.

Step 5, calculate the attenuation coefficient

According to the energy I calculated in step 4, the sorted empty water and breast data are calculated according to the following formula:

Atten=log(I _water /I _object )

Atten is the attenuation coefficient of each transmitting and receiving pair.

Step 6, image reconstruction

Reconstruct the processed Atten according to the following formula.

是第m个加权投影的衰减值，W_m+是第m个衰减对应的归一化因子，λ_k是第k次迭代的系数，

是整个成像系统的采样点，m'用来计算像素n和所有衰减相交距离的和，是一个常数的加权，可以提出去。Among them, f is the image, k is the number of iterations, n is the pixel number, w _mn is the intersection distance between the mth attenuation and the nth pixel, p _m is the mth attenuation value,

is the attenuation value of the mth weighted projection, W _m+ is the normalization factor corresponding to the mth attenuation, λ _k is the coefficient of the kth iteration,

is the sampling point of the entire imaging system, m' is used to calculate the sum of pixel n and all attenuation intersection distances, which is a constant weighting and can be proposed.

Step 7, image processing

Step 7.1, map the reconstructed image value to the interval of 0-255.

Step 7.2, according to the theoretical optimal imaging area, add a rectangular mask to the reconstructed images of the sagittal plane and the coronal plane, respectively. Mask is a two-dimensional matrix with 1 in the optimal area and 0 outside, and the image in the Mask Reserved, others are set to 0. The processed image will be stored in the specified memory location, and the GUI terminal will periodically read it.

Step 8, image GUI display

There are two windows on the GUI side (graphical user interface) to display the breast position images of the coronal plane and the sagittal plane respectively, to judge whether the patient's breast position is in the optimal area. If the breast is not in the optimal imaging area, instruct the patient to move and adjust the breast position until the breast is in the optimal area.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (9)

1. A fast imaging method for locating a breast of a hemispherical ultrasonic tomography system is characterized by comprising the following steps:

step 1, acquiring empty water data;

step 2, breast data acquisition;

step 3, analyzing the acquired data;

step 4, preprocessing the analyzed data;

step 5, calculating an attenuation coefficient;

step 6, reconstructing an image;

and 7, processing the reconstructed image, and storing the processed image in a specified memory location.

2. The fast imaging method for locating the breast in the hemispherical ultrasonic tomography system as claimed in claim 1, wherein in the step 1 and the step 2, the data of the coronal plane and the data of the sagittal plane are acquired simultaneously at each acquisition.

3. The fast imaging method for breast localization in hemispherical ultrasound tomography system according to claim 1, wherein the step 3 comprises:

and the transmitting TAS serial number, the transmitting array element serial number, the receiving TAS serial number, the receiving array element serial number and a segment of AScan are corresponding and stored in the memory.

4. The fast imaging method for breast localization in hemispherical ultrasound tomography system according to claim 1, wherein the step 3 comprises: the sagittal plane data and the coronal plane data are distinguished and are respectively used for the reconstruction of sagittal plane images and coronal plane images.

5. The fast imaging method for breast localization of hemispherical ultrasonic tomography system as claimed in claim 1, wherein the step 4 comprises:

step 4.1, calculating the energy of each segment of the AScan signal according to the following formula:

wherein, L is the characteristic length of the transmitted signal, and t0 is the arrival time of the direct wave;

step 4.2, LOR sequencing, comprising: connecting all transmitting array elements and receiving array elements in a Line, solving the polar coordinate transformation result of the Line in the original rectangular coordinate system, arranging signals into (R, theta) matrixes, wherein R is the distance from a path to a central point, theta is the included angle between the path and coordinate axes, and the data of the sagittal plane and the coronal plane are separately subjected to LOR sequencing.

6. The fast imaging method for locating the breast of the hemispherical ultrasonic tomography system as claimed in claim 5, wherein the step 5 comprises:

and 4, calculating the sorted empty water and breast data according to the energy I calculated in the step 4 according to the following formula:

Atten＝log(I _{empty water} /I _Object )

Wherein the Atten is the attenuation coefficient of each transmit-receive pair.

7. The fast imaging method for breast localization in hemispherical ultrasound tomography system according to claim 6, wherein the step 6 comprises:

the processed Atten is reconstructed according to the following formula:

where f is the image, k is the number of iterations, n is the pixel number, w _mm Is the intersection distance, p, of the mth attenuation and the nth pixel _m Is the m-th attenuation value of the signal,

is the attenuation value of the mth weighted projection, W _m+ Is the normalization factor, λ, corresponding to the mth attenuation _k Is the coefficient of the k-th iteration,

is the sampling point, w, of the entire imaging system _m’n Is the sum of pixel n and all attenuation crossover distances, and m' is used to calculate the sum of pixel n and all attenuation crossover distances, which is a constant weight.

8. The fast imaging method for breast localization of hemispherical ultrasonic tomography system as claimed in claim 1, wherein the step 7 comprises:

step 7.1, mapping the reconstructed image value to an interval of 0-255;

and 7.2, respectively adding a Mask with a rectangular frame to the reconstructed images of the sagittal plane and the coronal plane according to the theoretical optimal imaging area, keeping the images in the Mask, setting the images except the Mask as 0, storing the processed images in a specified memory position, and periodically reading through a GUI (graphical user interface) terminal.

9. The fast imaging method for breast localization of hemispherical ultrasonic tomography system as claimed in claim 1, further comprising the step 8 of: the GUI end respectively displays the breast position images of the coronal plane and the sagittal plane through two windows so as to judge whether the breast position of the patient is in the optimal area.

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