Magnetic resonance frequency and phase position double-encoding sampling method and image reconstruction method

Abstract

The invention discloses a magnetic resonance frequency and phase position double-encoding sampling method and an image reconstruction method. The sampling method comprises the following steps of (a) setting an acquisition sequence and acquiring k-space data; (b) performing N-time over-sampling to the frequency encoding gradient direction according to the acquisition sequence during acquisition and simultaneously adding frequency encoding gradient and phase position encoding gradient to control data acquisition tracks; (c) filling the data acquired in the step (b) into a k-space through an analog to digital converter (ADC) to form the k-space with an inclination factor N, wherein data points of the k-space are distributed along the frequency encoding gradient direction and the phase position encoding gradient direction in an inclined N*m rows*n columns mode, and (N-1) blank data points are filled between every two adjacent actually acquired data points in the frequency encoding direction and the phase position encoding direction, the N is an integer larger than 1, and the m and the n are positive integers. The magnetic resonance frequency and phase position double-encoding sampling method enables phase positions and frequency to be encoded simultaneously so as to control the k-space sampling tracks, enables acquisition times to be less than the acquisition s times of a traditional acquisition s mode, shortens the total acquisition time and enables reconstructed images not to have image artifacts basically.

Description

technical field [0001] The invention relates to magnetic resonance imaging technology, in particular to a frequency-phase double-coded sampling method and an image reconstruction method thereof. Background technique [0002] In the existing magnetic resonance imaging technology, the imaging method needs to fill up the k-space, and then perform Fourier transform on the filled k-space, and finally obtain a reconstructed image. The general data collection method is shown in Figure 1, in which, Figure 1a It is a schematic diagram of the gradient control of the readout direction and the ADC acquisition control after a certain phase encoding. The ADC is an analog-to-digital converter, that is, a signal collector. Figure 1b The solid point in ), the dotted arrow indicates the oversampled data (corresponding to Figure 1b The triangle point in ), the oversampled data is the data increased by increasing the ADC acquisition speed; Figure 1b The dot in the middle represents the co...

AI Technical Summary

Problems solved by technology

In the common method, the frequency encoding direction can speed up the acquisition speed and reduce the step size without affecting the overall acquisition time; but if the phase encoding direction reduces the step size, the acquisition time will be longer

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