A kind of image processing method and device for suppressing fat signal

Abstract

The invention discloses an image processing method and an image processing device for suppressing a fat signal. The image processing method comprises the steps that: a magnetic resonance system carries out Fourier transform on a collected free induction decay signal to obtain a resonance frequency distribution spectrum of hydrogen protons in water and fat; the magnetic resonance system analyses the resonance frequency distribution spectrum of the hydrogen protons in water and fat, so as to obtain resonance frequency distribution situations of actual fat hydrogen protons and match fat saturation pulses; and the magnetic resonance system performs fat saturation by utilizing the fat saturation pulses obtained through matching, so as to suppress the generation of the fat signal and generate a fat suppression image of magnetic resonance. The image processing method and the image processing device apply the fat saturation pulses with different bandwidths and central frequencies according to the resonance frequency distribution situations of actual fat hydrogen protons, suppress the fat signal by means of the fat saturation pulses, and improve the success rate of fat suppression, thereby acquiring the magnetic resonance image with obvious fat suppression effect.

Description

technical field [0001] The invention relates to the technical field of image processing, in particular to an image processing method and device for suppressing fat signals. Background technique [0002] In magnetic resonance, hydrogen protons in fat and water have different resonant frequencies due to chemical shift (the change in the position of the NMR signal of the proton due to the chemical environment). In some sequences, in order to better display the lesions, the fat signal needs to be suppressed, so it is necessary to first apply a narrow-band pulse targeting the resonance frequency of the hydrogen protons in the fat to saturate the hydrogen protons in the fat. Then, broadband pulses are used to excite the tissue normally. At this time, because the hydrogen protons in the fat are saturated, no signal will be generated. The image produced at this time is the fat-suppressed image of magnetic resonance. [0003] The existing technology uses pulses with fixed bandwidth ...

AI Technical Summary

Problems solved by technology

However, the resonance frequency of hydrogen protons in actual fat is not only affected by the chemical shift, but also affected by various factors such as local magnetic susceptibility and the geometry of the human body. There is a certain difference in the resonant frequency of the proton

If the pulse used to saturate fat hydrogen protons is applied according to the theoretically calculated bandwidth and center frequency, there will be a large difference, and some or all of the fat must not be saturated

In some parts of the human body where shimming is relatively easy, the fat suppression effect is better; while in places where shimming is difficult, such as tissues that are far away from the center or have a large difference in magnetic susceptibility, the fat suppression effect is relatively poor, so it is impossible to obtain Magnetic resonance images with obvious fat suppression effect

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