Effect of the Modified Look–Locker Inversion Recovery Sampling Scheme on Accuracy and Heart Rate Variability in Myocardial T1 Mapping

This study aimed to clarify the accuracy and variability of heart rate variability effects on T1 relaxation time values acquired using different sampling schemes of the modified Look-Locker inversion recovery (MOLLI) method. Five MOLLI sampling schemes-5(3)3, 5s(3s)3s, 4(1)3(1)2, 4s(1s)3s(1s)2s, and 3(3)3(3)5-were compared using a simulated electrocardiogram signal in a phantom experiment. The 5(3)3 and 5s(3s)3s schemes demonstrated high accuracy across the range of native and contrast-enhanced T1 values, with correlation coefficients exceeding 0.95 compared with the reference T1. Regarding heart rate variability, the 5(3)3 scheme showed minimal variation in the measured value across different heart rates, regardless of the T1 value, with an error rate below 6% relative to the reference T1. Therefore, the 5(3)3 scheme can achieve highly accurate measurements over a wide T1 range and is robust against heart rate variability.