Analytical T1, T2, proton density, and magnetic field inhomogeneity quantification in the brain using phase-cycled bSSFP

Motivation: Addressing the need for simplified, time-efficient, and unbiased quantitative imaging in human brain. Goal(s): Evaluating novel analytical method, ORACLE, to simultaneously quantify T1, T2, proton density (PD), and magnetic field inhomogeneity (B0) in human brain based on balanced steady-state free precession (bSSFP) profiles. Approach: Acquiring bSSFP data for simultaneous multi-parameter quantification and reference multi-echo spin-echo, MP2RAGE and dual-echo gradient-echo data in 4 human subjects. Results: Quantifications using bSSFP profiles and ORACLE was consistent with reference methods, although magnetization transfer effects led to a 15% consistent underestimation of T1. Proposed method has faster acquisition and parametric estimation comparing to other methods combined. Impact: This novel analytical time-efficient method extracts a wide range of quantitative parameters from bSSFP profiles, which can be a valuable alternative to existing reference methods, multi-echo spin-echo, MP2RAGE and dual-echo gradient-echo, that quantify one parameter at a time.