Abstract
PURPOSE: To develop a cardiac MR fingerprinting (cMRF) approach using deep image prior reconstruction (DIP) to simultaneously map T(1), T(2), and T(1ρ), and assess T(1ρ) in healthy subjects and patients with areas of enhancement on late gadolinium enhancement. METHODS: A 2D electrocardiogram-triggered cMRF sequence was developed to measure T(1), T(2), and T(1ρ) simultaneously. DIP reconstruction was evaluated for noise and artifact reduction compared to a low-rank reconstruction. Measurements were assessed in simulation and phantom for accuracy. T(1ρ)-cMRF maps were generated in 10 healthy subjects and six patients under evaluation for cardiomyopathy, myocarditis, and amyloidosis receiving gadolinium-based contrast agent-enhanced CMR at 1.5 T. RESULTS: T(1ρ)-cMRF maps showed excellent agreement with ground truth (RMS error = 3.0% ± 5.3%) and conventional methods (R(2) = 0.99) in simulations and phantom experiments. Measured values in healthy subjects were consistent with literature (T(1) = 1051 ± 63 ms, T(2) = 41.4 ± 3.3 ms, and T(1ρ) = 45.5 ± 2.4 ms). DIP reconstruction reduced noise, indicated by lower coefficient of variation (Δ = 4.7), compared to low-rank reconstruction. Mean differences of 10.2 ms (p = 0.02) in T(1ρ) and 6.9 ms in T(2) maps were observed between areas of enhancement on late gadolinium enhancement and normal-appearing myocardium in patients. Within individual patients, significant differences (p < 0.01) in T(1), T(2), and T(1ρ) were observed between American Heart Association segments with and without contrast enhancement. CONCLUSION: The proposed T(1ρ)-cMRF sequence using DIP reconstruction enables simultaneous quantification of T(1), T(2), and T(1ρ) with decreased coefficient of variation compared to low-rank reconstruction. Simulation and phantom studies show good agreement with references. In vivo measurements were made in healthy subjects, and areas of contrast enhancement in patients showed elevated T(2) and T(1ρ) relative to remote myocardium.