Tissue displacement measurement method and system based on magnetic resonance acoustic radiation force imaging

Abstract

The invention provides a tissue displacement measurement method and a tissue displacement measurement system based on magnetic resonance acoustic radiation force imaging. The tissue displacement measurement method comprises the following steps: acquiring an image obtained by utilizing a two-dimensional spin-echo sequence and applying focused ultrasound; dividing an object tissue in the image into a region of interesting and a reference region; separating to obtain a tissue phase diagram of the reference region; carrying out polynomial model fitting on the tissue phase diagram of the reference region, so as to obtain multinomial coefficients; carrying out interpolation by utilizing the multinomial coefficients, and calculating to obtain a baseline phase diagram of the tissue in the region of interesting; acquiring a tissue phase diagram of the region of interesting from the acquired image; acquiring the phase difference of the tissue of the region of interesting; and acquiring the displacement of the tissue of the region of interesting by utilizing the phase difference of the tissue of the region of interesting. The method and the system are not insensitive to the tissue movement, the errors caused by the eddy and field uniformity can be reduced, the phase difference can be measured only through once of image collection, thus the displacement variation of the tissue can be obtained, and the displacement measurement speed of the tissue is accelerated.

Description

technical field [0001] The invention relates to the field of magnetic resonance-guided high-intensity focused ultrasound, in particular to a tissue displacement measurement method and system based on magnetic resonance acoustic radiation force imaging. Background technique [0002] Acoustic radiation force impulse (ARFI) is a phenomenon produced by sound waves propagating inside a material. When the frequency of the sound wave reaches the megahertz level, that is, ultrasound, the sound wave can produce two phenomena inside the propagating material: 1. When the sound wave propagates Direction generates momentum exchange, and second, heat generation. Among them, the momentum exchange can generate a force, which can push the propagating material to produce a certain displacement. There are several different ways to measure this displacement, which reflects the elastic stiffness of the sides of the sound-transmitting material. The displacement can be measured by conventional u...

AI Technical Summary

Problems solved by technology

This method uses a pair of unipolar motion encoding gradients, which will produce some unknown artifacts in the phase map, affecting the accuracy of the focus position measurement

Jing Chen et al. used a pair of bipolar motion encoding gradients to effectively correct the phase artifacts caused by eddy currents in the phase map, but still used the spin echo sequence, and the image acquisition speed was slow

Although other researchers have used echo-planar imaging (EPI) imaging technology in order to improve the image acquisition speed, it still needs to scan the sequence twice, which may cause image misregistration and cause large measurement error

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