Magnetic resonance CEST imaging sequence based on frequency stabilization module and device

Abstract

The invention discloses a magnetic resonance CEST imaging sequence based on a frequency stabilization module and a device. The method comprises the steps that first, in the frequency stabilization module, a small flip angle radio-frequency pulse excites a target layer, and three rows of non-phase encoded k-space data are collected; secondly, by calculating the phase difference between the first and second rows of non-phase encoded k-space data, the fine estimate of main magnetic field frequency drift is acquired; the rough estimate of main magnetic field frequency drift is acquired by calculating the phase difference between the second and third rows and the phase difference between the first and second rows; by comparing the difference between the rough estimate, the fine estimate and a threshold value, the value of main magnetic field frequency drift is determined; according to the calculation result of main magnetic field frequency drift, the center frequency of the radio-frequencypulse is adjusted to realize real-time correction of main magnetic field frequency drift; and finally, conventional magnetic resonance CEST imaging is carried out. According to the invention, real-time correction of main magnetic field frequency drift is realized when magnetic resonance CEST imaging is carried out; a fat signal is effectively suppressed; and the magnetic resonance CEST imaging performance is improved.

Description

technical field [0001] The present application relates to the field of magnetic resonance technology, in particular to the field of magnetic resonance CEST imaging frequency drift correction. Background technique [0002] Magnetic resonance CEST (Chemical Exchange Saturation Transfer) imaging is an important molecular magnetic resonance imaging technique that can detect free proteins and peptides in the endogenous cytoplasm in vivo. Magnetic resonance CEST imaging is also used for tumor detection and tumor grading because it can obtain information on overexpressed proteins and peptides in gliomas. However, magnetic resonance CEST imaging is very sensitive to the frequency drift of the main magnetic field. If the frequency drift of the main magnetic field is not corrected, the performance of magnetic resonance CEST imaging will be greatly affected. Based on the interference of the frequency drift of the main magnetic field on the imaging performance of magnetic resonance CES...

AI Technical Summary

Problems solved by technology

However, magnetic resonance CEST imaging is very sensitive to the frequency drift of the main magnetic field, and if the main magnetic field frequency drift is not corrected, the performance of magnetic resonance CEST imaging will be greatly affected

Based on the interference of the frequency drift of the main magnetic field on the imaging performance of magnetic resonance CEST, some researchers proposed a method to correct the frequency drift of the main magnetic field in the data post-processing. Although the data post-processing method can achieve the frequency correction of the main magnetic field well, it cannot guarantee Effectively suppress the fat signal, causing the excessively high fat signal in the CEST image to easily cover the normal tissue signal

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