1Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2Institute of Nuclear Medicine, UCLH-NHS Foundation Trust, London, United Kingdom
Magnetic susceptibility mapping has the potential to facilitate segmentation of air and teeth in the head due to their different magnetic susceptibilities, though there is no phase signal in these regions. An iterative phase replacement method to
improve the calculation of susceptibility distributions in regions with no
phase signal is validated using a numerical phantom consisting of three classes: air, teeth and tissue with the phase image set to zero in the air and teeth to simulate the real case. Calculated susceptibility distributions in regions with no phase signal were not accurate and standard deviations were seen to increase in some regions, though
the iterative technique improved a simple segmentation.