Accuracy, precision, and reproducibility of myocardial T1 mapping: A comparison of four T1 estimation algorithms for modified look‐locker inversion recovery (MOLLI)

Purpose To compare the accuracy and precision of four different T1 estimation algorithms for modified Look‐Locker inversion recovery (MOLLI). Methods Four T1 estimation algorithms, including the original fit, inversion group (IG) fit, instantaneous signal loss simulation (InSiL), and Bloch equation simulation with slice profile correction (BLESSPC) were studied. T1 estimation accuracy, precision, reproducibility, and sensitivity to heart rate (HR), flip angle (FA), and acquisition scheme (AcS) variations were compared in simulation, phantom, and volunteer studies. Results T1 estimation accuracy of IG (‐2.4% ± 3.9%) and original fit (‐3.2% ± 1.4%) were worse than BLESSPC (0.2% ± 1.5%) and InSiL (‐0.7% ± 2.1%). The original fit had the best precision for T1 from 409–1884 ms for the same FA (0.67% ± 0.16% versus 0.90% ± 0.23% using IG, 0.78% ± 0.11% using InSiL, 0.77% ± 0.12% using BLESSPC). BLESSPC generated the most consistent in vivo T1 values over different FAs and AcS, and the T1 estimation reproducibility was similar ( P  > 0.3) among the four methods when FA = 35°. When using FA = 50°, the reproducibility was significantly improved only when using BLESSPC (1.6% ± 0.9 versus 2.6% ± 1.9%, P  < 0.05). Conclusion BLESSPC has superior accuracy and is the least sensitive to FA, HR, and AcS variations. T1 estimation using BLESSPC and FA = 50° is superior to conventional MOLLI with FA = 35° in accuracy and precision. Further clinical studies in varying pathological conditions are warranted to confirm our findings. Magn Reson Med 78:1746–1756, 2017. © 2016 International Society for Magnetic Resonance in Medicine.