RESUME^N: A flexible class of multi-parameter qMRI protocols

Purpose: To introduce a class of fast 3D quantitative MRI (qMRI) schemes (RESUME, for N=1,...,4) that allow for a thorough characterization of microstructural properties of brain tissues. Methods: An arbitrary multi-echo GRE acquisition optimized for quantitative susceptibility mapping (QSM) is complemented with an appropriate low flip-angle GRE sequence drawn from four possible choices. The acquired signals are processed to analytically derive the longitudinal relaxation (R) and free induction decay (R) rates, as well as the proton density (PD) and QSM. A comprehensive modeling of the excitation and B profiles and of the RF-spoiling is included in the acquisition and processing pipeline. Results: The RESUME maps appear homogeneous throughout the field-of-view and exhibit comparable values and high SNR across the considered range of N values. Conclusions: The introduced schemes represent a class of robust and flexible strategies to derive a thorough and fast qMRI study, suitable for a whole-brain acquisition with isotropic voxel resolution of 700 ?m in less than 15 min.