Multi-frequency alternative-ejecting real-time ultrasonic elastography method

Abstract

The invention discloses a multi-frequency alternative-ejecting real-time ultrasonic elastography method which comprises the steps of: 1, alternatively ejecting N kinds of frequency ultrasonic waves by an ultrasonic probe in a process of extracting tissues by using hands; 2, carrying out displacement estimation on adjacent same frequency echoes by using a two-dimensional weighting phase separation algorithm; 3, equally weighting N frames of continuous different frequency displacement images to generate a compound displacement image; 4, carrying out gradient operation on the compound displacement image to generate a strain image; and 5, carrying out downsampling on the strain image and carrying out gray scale mapping, and scanning and converting into an elastic image. According to the method, displacement images with different noise modes are generated by using different ejecting frequencies, the displacement estimation error is reduced through compounding of the displacement images, and the elastography pseudomorphism noise caused by speckle noise is inhibited. The signal to noise ratio of the elastic image generated by the compound image is higher than that of an elastic image generated by compounding the former frequency sub-displacement image, and therefore, the property and the quality of elastography are improved.

Description

technical field [0001] The invention belongs to the technical field of ultrasound elastography for medical imaging, and specifically relates to a multi-frequency alternate emission real-time ultrasound elastography method, which is mainly used in but not limited to the field of manual breast compression ultrasound elastography. Image Processing. Background technique [0002] Ultrasound (Ultrasound) elastography (Strain Imaging) uses ultrasonic waves to detect the relative hardness information of human tissue. It is an economical, non-destructive, convenient and fast new medical imaging mode. This imaging method has become one of the important methods for early disease screening, accurate diagnosis, precise treatment and prognosis assessment, especially for early detection of tumors. This imaging method usually involves applying static or quasi-static excitation to the tissue, estimating the distribution of tissue displacement (Displacement) under the excited state by analyz...

AI Technical Summary

Problems solved by technology

[0005] 1. The complexity of the breast tissue structure causes the amplitude of the echo signal to fluctuate randomly and violently. Due to the influence of the amplitude fluctuation of the signal, the displacement generated by the weighted phase separation displacement estimation algorithm based on the one-dimensional window will have a large error. This error makes the elastic image Strong noise is generated, which seriously affects the image quality and doctor's diagnosis

Existing denoising methods and technologies have no obvious denoising effect on this kind of noise, and it is difficult to achieve an ideal denoising effect while keeping the boundaries of the lesion area clear

[0006] 2. During freehand compression imaging, there is a certain amount of lateral movement in the breast tissue. Using a one-dimensional window to estimate the displacement on a scan line will produce obvious errors, and even cause error displacement propagation.

The existence of these errors or errors will further increase the image noise, and in severe cases, the left and right of the image will be discontinuous, resulting in "vertical stripes" in the final image

[0007] 3. Freehand compression elastography has high requirements on the operation method and level of doctors, but the existing elastography methods usually do not have operation status display and feedback modules

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