Decoding the phase-cycled bSSFP signal for maximized parameter quantification - T1, T2, proton density and magnetic field inhomogeneity

A novel analytical method for off-resonance encoded parameter quantification of voxel-wise phase-cycled bSSFP signal profiles was developed. The approach conserves both magnitude and phase information in a complete, linearized, and compact way. A framework for ultra-rapid and simultaneous $T₁$, $$T₂$, $$B₀$ inhomogeneity and proton density quantification were developed. The approach was validated in simulations, phantom and in vivo knee experiments and compared with gold-standard reference measurements when available. Simulations and experiments validated the proposed method for multi-parameter quantification with high accuracy and precision, providing the first step towards novel analytical quantification possibilities with phase-cycled bSSFP.