Samuel James Wharton1, Andreas Schfer2, Richard Bowtell1
1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK; 2Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
Phase images generated using gradient echo techniques at high field strengths show excellent contrast related to the different magnetic susceptibilities of various brain tissues. However, extraction of accurate anatomical information from these images is made difficult by the non-local relationship between the field perturbation and associated susceptibility distribution. Here, we validate a Fourier-based method for calculating 3D susceptibility maps from phase data using a specially-constructed agar phantom containing doped inclusions of known susceptibility. Results produced by applying the method to measuring the susceptibility of the substantia nigra and red nuclei from data acquired at 3 and 7T are also discussed.