Magnetic resonance CEST imaging frequency drift correction method and device, medium and imaging equipment

Abstract

The invention discloses a magnetic resonance CEST imaging frequency drift correction method and device, a medium and imaging equipment. The method comprises the following steps of: firstly, in a frequency drift correction module, exciting a target layer by using a small-flip-angle radio frequency pulse, and acquiring a single-row free induction attenuation signal or two-row non-phase encoding gradient echo signals; secondly, according to the phase information and the acquisition time of a single-row free induction attenuation signal or two-row non-phase coding gradient echo signals, calculating main magnetic field frequency drift values respectively; adjusting the center frequency of the magnetic resonance equipment in real time according to the main magnetic field frequency drift calculation value to realize real-time correction of the main magnetic field frequency drift; carrying out CEST imaging. Aiming at the problem of main magnetic field frequency drift in magnetic resonance CESTimaging, the invention provides a frequency drift correction module for correcting frequency drift in real time based on acquisition of a free induction attenuation signal or a non-phase encoding gradient echo signal, and therefore the robustness and repeatability of magnetic resonance CEST imaging are 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 a new type of molecular magnetic resonance imaging technology. Compared with conventional magnetic resonance imaging technology, this technology can indirectly detect the spatial distribution of endogenous low-concentration metabolites. Its clinical application value has been verified in various diseases. Since CEST imaging is affected by various interference effects such as direct water saturation, asymmetric magnetization analysis (Magnetization Transfer Ratio Asymmetry Analysis, MTRasym) is often used clinically to remove other interference effects to propose a pure CEST effect. However, the MTRasym analysis method is very sensitive to the frequency drift of the main magnetic fie...

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Problems solved by technology

However, the MTRasym analysis method is very sensitive to the frequency drift of the main magnetic field. The frequency drift of the main magnetic field will cause the MTRasym analysis method to significantly overestimate or underestimate the CEST effect, which will affect the robustness and repeatability of magnetic resonance CEST imaging.

Although some researchers have adopted some post-processing methods to correct the frequency drift of the main magnetic field, the post-processing method cannot solve the problem of reduced fat suppression efficiency caused by the frequency of the main magnetic field, resulting in a higher fat signal in the CEST image. Reduced clinical reference value of CEST images

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