A Comparison of T2* Magnitude, SWI, K-Division Susceptibility Map, Maxwell Equation Regularized Quantitative Susceptibility Map for Brain Iron Mapping

James R. Ledoux¹, Tian Liu¹, Jing Liu¹, Ildar Khalidov¹, Martin Prince¹, Yi Wang¹

The reconstruction methods of Quantitative Susceptability Mapping (QSM), Susceptability Weighted Imaging (SWI), and truncated k-space division all desire to reveal an image of susceptability sources. It is difficult to directly find susceptability sources from the magnetic field map (obtained by phase information) as the dipole convolution kernel has zeros in k-space. However, the inversion problem can be regularized to provide a solution as shown in the QSM method. We compare this to direct inversion of the convolution by truncating the convolution kernel near ill-conditioned values, and with SWI which is a phase-masked T2* image.