Analyzing the Influence of Imaging Parameters on Cardiac T1 Estimation Accuracy Using MOLLI

It has been shown that quantitative imaging has potential to be used for diagnosis and these maps may provide better diagnostic results compared to qualitative images. In particular, T1 map has been used as a biomarker for diagnosis in some cardiac diseases. Accuracy in estimation of T1 is important in this approach and, therefore, it is necessary to identify and minimize error sources in these maps. MOLLI sequence, as a well-known method for cardiac T1 mapping, has been simulated in this study in order to analyze the influence of TR, TI, flip-angle and off-resonance on T1 estimation in MOLLI. We have shown that in order to minimize the T1 estimation error in MOLLI, TR should be in the range of 1.5 to 2ms also Inversion Time (TI) should be set to TI=150ms. In order to minimize the error using flip angle, small flip angles in the range of α=200 to 30° are desired. Also we have shown that off-resonance causes error on T1 estimation even in pass-band region of SSFP profile. Therefore this source of error should be considered and off-resonance must be as low as possible when MOLLI is used for T1 estimation.