High resolution rotating frame relaxation mapping with T-NORDIC

Current whole-brain implementations of rotating frame relaxation (RFR) mapping are generally limited to moderate spatial resolutions due to acquisition time limitations. We propose using transform domain NORDIC, T-NORDIC, to increase the quality of RFR maps at both moderate and high spatial resolution. The results show clear improvements in terms of fitting reliability for estimation of adiabatic T1ρ and T2ρ, and especially Relaxation Along a Fictitious Field in rotating frame of rank n=4 (RAFF4) after applying NORDIC denoising. The improvements in map quality can be leveraged to reduce acquisition times in clinical applications.