Simultaneous T, T, and T mapping of the myocardium using cardiac MR fingerprinting with a deep image prior reconstruction.

PURPOSE

To develop a cardiac MR fingerprinting (cMRF) approach using deep image prior reconstruction (DIP) to simultaneously map T, T, and T, and assess T 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, T, and T 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-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-cMRF maps showed excellent agreement with ground truth (RMS error = 3.0% ± 5.3%) and conventional methods (R = 0.99) in simulations and phantom experiments. Measured values in healthy subjects were consistent with literature (T = 1051 ± 63 ms, T = 41.4 ± 3.3 ms, and T = 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 and 6.9 ms in T 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, T, and T were observed between American Heart Association segments with and without contrast enhancement.

CONCLUSION

The proposed T-cMRF sequence using DIP reconstruction enables simultaneous quantification of T, T, and T 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 and T relative to remote myocardium.