Phase Correction of MRSI Data Using Model-Based Signal Estimation and Extrapolation

Motivation: In many MRSI applications, it is desirable to generate absorption-mode spectra, which requires correction of phase errors. Goal(s): We propose a novel model-based method for effective phase correction of MRSI data. Approach: The proposed method determined the zeroth-order phase and acquisition dead time using a Lorentzian-based spectral model and performed signal extrapolation using a generalized series model. Absorption-mode spectra were then generated from the phase-corrected and extrapolated MRSI data. Results: The proposed method was evaluated using both simulated data and experimental data acquired from human brains in multi-nuclei (31P, 2H, and 1H) MRSI experiments, producing high-quality absorption-mode spectra. Impact: We propose a novel method for effective phase correction of MRSI data. This method is expected to provide a useful tool for processing, quantifying, and analyzing MRSI data.