Susceptibility Mapping in the Human Brain at 3 and 7T

Introduction: Phase images generated using gradient echo techniques at high field strengths show excellent contrast related to the different magnetic susceptibilities of various brain tissues [1,2]. However, extraction of accurate anatomical information from these images is made difficult by the non-local relationship between the field perturbation and the associated susceptibility distribution [3]. Here, we present a Fourier-based method for calculating 3D susceptibility maps from phase image data. We describe a validation of this approach by analysis of data from a phantom containing different compartments of known susceptibility and the results produced by applying the method to real brain data acquired at 3T and 7T are also discussed.