A Comparison of Tissue Property Values Estimated Using Conventional Cardiac
MRF
and
MT
‐Cardiac
MRF
Sydney Kaplan, Zexuan Liu, Jesse Hamilton, Shaihan Malik, Chaitanya Madamanchi, Venkatesh Murthy, Scott Swanson, Nicole Seiberlich ABSTRACT
Purpose
To evaluate the impact of explicitly modeling Magnetization Transfer (MT) during reconstruction of cardiac Magnetic Resonance Fingerprinting (cMRF) maps on T 1 and T 2 quantification.
Methods
cMRF data were reconstructed using two dictionaries: a conventional cMRF dictionary that ignores MT processes, and an MT‐cMRF dictionary modeling T 1 and T 2 of the free water pool ( T 1f and T 2f , respectively), as well as the bound pool fraction (BPF) as free parameters. Measurements which include MT processes were assessed in simulation and phantom to ensure that T 1f , T 2f , and BPF could accurately be measured using cMRF. cMRF data were then collected in 14 healthy subjects to measure T 1 / T 1f , T 2 / T 2f , and BPF in normal myocardium. Finally, cMRF data were acquired in five patients with known or suspected myocardial scar at 1.5T, and tissue property maps both ignoring and including MT were generated. Linear discriminant analyses (LDA) were performed to assess differences in tissue property values between scar and remote myocardium.
Results
MT‐cMRF showed excellent agreement with ground truth simulations (RMS error = 2.4% ± 3.9%) and phantom measurements ( R 2 = 0.99). Values measured with MT‐cMRF in healthy subjects ( T 1f = 1137 ± 72 ms, T 2f = 42.8 ± 4.2 ms, BPF = 8.2% ± 1.2%) were significantly different than conventional cMRF ( T 1 = 947 ± 75 ms, T 2 = 41.5 ± 3.9 ms). T 1f / T 2f and T 2f /BPF from MT‐cMRF demonstrated higher LDA accuracy (82.4% and 86.1%) in discriminating scar from healthy tissue than T 1 and T 2 from conventional cMRF (61.8%).
Conclusion
Incorporating MT modeling into cMRF results in improved T 1f and T 2f quantification compared to conventional modeling and enables BPF measurement. Native MT‐cMRF T 1f , T 2f , and BPF values showed differences between scar and healthy myocardium.