Amanda Ng1,2, Zhaolin Chen2,3,
Jingxin Zhang1, Gary F. Egan2,4, Leigh A. Johnston2,5
1Department of Electrical and Computer
Systems Engineering, Monash University, Melbourne, Australia; 2Howard
Florey Institute, Florey Neuroscience Institutes, Melbourne, Australia; 3Department
of Electrical and Electronic Engineering, University of Melbourne, Melbourne,
Australia; 4Centre for Neuroscience, University of Melbourne,
Melbourne, Australia; 5Department of Electrical and Electronic
Engineering & NICTA Victorian Research Laboratory, University of
Melbourne, Melbourne, Australia
Phase
images in MRI are subject to inhomogeneities at the cortical surface due to
susceptibility artefacts induced by air/tissue interfaces and insufficient
filtering at foreground/background borders. We present a computationally
efficient method of removing these inhomogeneities from phase unwrapped
images using spatially dependent filters and omission of background voxels
from the filtering calculations. The method is shown to successfully reveal
structural detail in the cortical surface that is otherwise obscured in
traditional filtering methods.