Magnetic Resonance Fingerprinting of the Chemical Exchange Relayed Nuclear Overhauser Effect In Vivo (rNOE-MRF)

Motivation: Despite its demonstrated ability to provide biological insights into various pathologies, relayed nuclear Overhauser effect (rNOE) imaging is lengthy and biased by water T1 and semisolid MT contrast. Goal(s): To develop a rapid rNOE quantification MR-Fingerprinting (MRF) method and validate its performance in-vivo. Approach: An rNOE-MRF acquisition protocol was designed and employed at 7T for imaging three in-vitro tissue types and wild-type mice (n=7). Quantitative glycogen, rNOE, and semisolid MT maps were simultaneously reconstructed. Results: In-vitro rNOE exchange parameter maps were highly correlated with ground truth (r>0.99, p<0.01, NRMSE<7%). The rNOE and MT quantitative trends in mice were in agreement with previous literature. Impact: A quantitative molecular MR-Fingerprinting method was developed, allowing for the simultaneous extraction of rNOE and semisolid MT proton-exchange parameter maps. These in-vivo, bias-dismantled maps are expected to aid in the diagnosis and characterization of cancer, stroke, and spinal cord injury.