Quantitative Susceptibility Mapping from Unsuppressed Water Signals in 1H-MRSI Data

This work presents a new method to extract QSM from the unsuppressed water signals in 1H-MRSI data and enables simultaneous MRSI and QSM in a single acquisition. The proposed method builds on the recently proposed subspace imaging method called SPICE (SPectroscopicImaging by exploiting spatiospectral CorrElation), which allows MRSI acquisition without water suppression, thus encoding susceptibility induced phase variations in the water spectroscopic signals. Parallel imaging, subspace-based modeling and constrained reconstruction are integrated to generate QSM and high-resolution MRSI reconstruction from such data. In-vivo experiment results demonstrate the capability of proposed method in producing susceptibility map along with metabolite spatiospectral distributions from a single 6-minute scan.