Echo planar imaging sequence image reconstruction method

Abstract

The invention provides an echo planar imaging sequence image reconstruction method comprising the following steps: acquiring echo planar imaging data Si and simultaneously acquiring three non-phase-encoded reference echo signals R1, R2 and R3; working out a parameter required for correcting the echo planar imaging data according to the reference echo signals; performing one-dimensional Fourier transform on the echo planar imaging data along a readout direction to obtain a transform result FSi, correcting FSi with the use of the correction parameter, and working out corrected echo planar imaging data; and performing one-dimensional Fourier transform on the corrected echo planar imaging data along a phase encoding direction to obtain an image. According to the echo planar imaging sequence image reconstruction method provided by the invention, in the presence of a stray field, the quick imaging advantage of echo planar sequence imaging can be kept, N / 2 artifacts can be effectively removed, and image deformation due to the existence of the stray field can be corrected.

Description

【Technical field】 [0001] The invention relates to the field of magnetic resonance imaging, in particular to a method for reconstructing an echo plane imaging sequence image. 【Background technique】 [0002] In the current magnetic resonance imaging process, the echo plane imaging sequence is a fast magnetic resonance imaging sequence that only requires a single excitation pulse to obtain a complete image. The magnetic resonance gradient system is periodically transformed to produce a series of gradient echoes; the image of the stimulated plane is obtained by applying a Fourier transform to the resulting echo sequence. [0003] In conventional echo plane imaging, the phase-encoding gradient and frequency-encoding gradient of the sequence are respectively as follows figure 1 A and b represented in , due to imperfect hardware system, such as eddy current, data acquisition delay, magnetic field drift, etc., there are differences in the data read out under positive and negative f...

AI Technical Summary

Problems solved by technology

[0009] In order to solve the problems of poor elimination of N / 2 artifacts, inability to correct image distortion, and long acquisition time in the echo-planar imaging sequence in the prior art, the present invention provides a more accurate echo-planar imaging sequence image reconstruction method

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