MRI WITH DIXON-TYPE WATER/FAT SEPARATION AND PRIOR KNOWLEDGE ABOUT INHOMOGENEITY OF THE MAIN MAGNETIC FIELD

摘要

The invention relates to a method of MR imaging of at least two chemical species having different MR spectra. It is an object of the invention to provide a method that enables Dixon water/fat separation in cases in which a large field-of-view is required. The method of the invention comprises the steps of:
a) generating at least one echo signal by subjecting a body placed in the examination volume of a MR device to an imaging sequence of RF pulses and switched magnetic field gradients;
b) acquiring the at least one echo signal;
c) separating signal contributions of the at least two chemical species to the at least one acquired echo signal on the basis of a spectral model and prior knowledge about the spatial variation of the main magnetic field B 0 in the examination volume; and
d) reconstructing a MR image from the signal contributions of at least one of the chemical species. Moreover the invention relates to a MR device and to a computer program to be run on a MR device.