Simultaneous T1 and T2 mapping of the brain with accelerated QuantoRAGE using optimized sequence parameters and fast neural network fitting

Motivation: T1 and T2 relaxometry provide valuable information for early pathology detection but require long scan and fitting times for high-resolution whole-brain mapping. Goal(s): To reduce acquisition and map generation times for simultaneous T1 and T2 mapping. Approach: The proposed accelerated sequence uses two scans instead of the original four, with parameters optimized using the Cramér-Rao lower bound (CRLB). A neural network fast fitting model is employed to drastically reduce parameter quantification times. Results: The optimized technique reduced total acquisition time from 18:20 to 9:10 minutes and fitting time from several hours to 2 min for the entire brain. Impact: Using QuantoRAGE, simultaneous T1 and T2 relaxometry of the whole brain with high isotropic resolution can be acquired in 9 minutes with quantitative maps generated within few seconds per slice. Both aspects bring quantitative MRI closer to clinical applications.