MR imaging using Dixon water / fat separation

摘要

An improved method of MR imaging of at least two chemical species having different MR spectra, such as water and fat, enables a precise quantification of water and fat or derived measures, such as a fat fraction. The method includes the steps of: a) generating two or more echo signals at different echo times by subjecting a body (10) placed in the examination volume of a MR device (1) to an imaging sequence of RF pulses and switched magnetic field gradients; b) acquiring the two or more echo signals; c) separating signal contributions of the at least two chemical species to the acquired echo signals on the basis of a signal model including the MR spectrum of each of the chemical species, the spatial variation of the main magnetic field in the examination volume, the effective transverse relaxation rate, and eddy current-induced phase errors. The eddy current-induced phase errors are estimated by a fitting procedure from the two or more echo signals.