Method for reducing PROPELLER sequence artifacts

Abstract

The invention discloses a method for reducing PROPELLER sequence artifacts, which comprises a data acquisition part and a data reconstruction part, and is characterized in that the data acquisition part comprises the following steps: step dS1, acquiring PROPELLER sequence acquisition track parameters; step dS2, carrying out first excitation, and collecting an ETL echo chain; step dS3, repeatedly executing the step dS2; step dS4, repeatedly executing the step dS2 and the step dS3; step iS1, carrying out self-phase correction on data lines excited for multiple times in each data band; step aiS1,adjusting the data band; step iS5, processing the data to obtain a final image, wherein the step aiS1 comprises the following steps: step iS2, performing inter-band phase correction between data bands. According to the invention, the data lines excited and collected for multiple times are filled into one data band, so that the effect of increasing the width of the data band is achieved to enablethe data band formed by multiple excitation combinations to meet the requirements of a subsequent PROPELLER reconstruction algorithm; star-shaped artifacts are eliminated; and motion artifacts are eliminated.

Description

technical field [0001] The invention relates to a method for reducing nuclear magnetic resonance equipment artifacts, in particular to a method for reducing PROPELLER sequence artifacts. Background technique [0002] Magnetic resonance imaging (MRI) technology has become an important means in medical diagnosis. When the subject moves during the scanning process, motion artifacts will appear in the images obtained by conventional scanning techniques, and severe motion artifacts may even affect clinical medical diagnosis. The Periodically Rotated Overlapping Parallel Lines with Enhanced Reconstruction (PROPELLER) sequence collects magnetic resonance data in a manner similar to propeller rotation, and adds a motion correction function to the reconstruction module, which can effectively reduce the MRI artifacts. [0003] After the PROPELLER sequence is excited once, several echo signals are collected as data lines to form a data band, and multiple data bands rotating around th...

AI Technical Summary

Problems solved by technology

However, when the hardware configuration of the system is not strong, or the magnetic resonance signal attenuates prematurely and disappears due to the short T2 relaxation time of the scanned tissue, and the number of data lines collected after one excitation of the PROPELLER sequence is small, the complete data cannot be obtained. There are obvious star-shaped artifacts in the image (the data acquisition schematic diagram is attached figure 1 shown)

A common solution to reduce starburst artifacts is to increase the number of PROPELLER data bands (the data collection diagram is attached figure 2 shown), but each data band in this scheme contains relatively few data lines, which causes the effect of the motion correction module in the subsequent image reconstruction to be greatly reduced

The above defects limit the application of PROPELLER sequence in magnetic resonance imaging system

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