An Automatically Optimised Gaussian Weighting Function Width for Magnitude-Weighted Phase-Based Electrical Properties Tomography (EPT)

Motivation: Phase-based electrical properties tomography calculates conductivities by fitting the transceive phase weighted by a Gaussian function of the magnitude image with width δ. Currently, δ is selected empirically and its impact on conductivities is unknown. Goal(s): To investigate the effect of δ on conductivity maps and develop a method to automatically select δ. Approach: After evaluating relationships between δ and healthy brain conductivities at 3T, we calculated conductivities using a voxel-wise δ based on inverse phase noise and compared the results. Results: Increasing δ decreased contrast and noise in conductivity maps. Our new method to calculate a varying δ automatically optimised conductivity maps. Impact: We have developed a method to calculate a varying Gaussian weighting width for EPT. This will enable automatic optimisation of conductivity maps rather than time-consuming empirical choice of δ, facilitating the use of phase-based EPT and broadening its applicability.