Magnetic resonance fingerprint imaging method with variable echo number

Abstract

The invention discloses a variable-echo-number magnetic resonance fingerprint imaging method, and the method also introduces the change of the number of echoes besides the conventional MRF coding through the conversion of an excitation pulse angle, so that quantitative diagrams of B0, B1 + and T1 can be obtained through single scanning. Furthermore, if the echo time corresponding to the same phase, the opposite phase and the same phase of the water and the fat is set for the three continuous echoes, the water and the fat can be imaged, and accurate quantification of B0, B1 + and the like is achieved. In-vivo experiments and simulation prove the effectiveness of the invention, so that the invention can provide various information representations for common brain diseases (glioma) and fat diseases (such as lipoma, fatty liver and the like), and is beneficial to clinical diagnosis and treatment.

Description

technical field [0001] The invention belongs to the technical field of magnetic resonance imaging, and in particular relates to a magnetic resonance fingerprint imaging method by changing the number of echoes. Background technique [0002] Magnetic resonance fingerprinting (Magnetic Resonance fingerprinting, MRF) is a relatively accurate MRI quantitative acquisition method. It encodes signals by introducing pseudo-random changes in sequence parameters, and can obtain multiple tissue parameters through one acquisition. Signal, and then through steps such as establishing a signal evolution dictionary and pattern matching, the quantitative parameter value of each pixel of the collected image signal can be obtained, including T 1 (longitudinal relaxation), T 2 and (Lateral relaxation), etc. These parameters are used to describe the physiological characteristics of tissues and organs, and have important significance and reference value for scientific research and clinical diag...

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Problems solved by technology

[0004] Another source that will affect the quantitative accuracy of magnetic resonance fingerprints is fat. The resonance frequency of fat has a certain frequency shift compared with water, and the relaxation time of the two is also different. Therefore, the actually collected signals are water and fat. the sum of the signals; if fat is ignored, it will affect the quantification accuracy of adipose tissue

At present, the main solutions include the following two: the first is to represent the signals of fat and water with a multi-component model, and then build a huge dictionary to match the obtained signals, which will contain the signals of fat and water. The respective parameters (T 1 , T 2 etc.), and finally obtain the parameter distribution map of interest through dictionary matching; this method is very time-consuming, and is often combined with some dictionary compression methods to speed up

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