An Intuitive Model of Several Factors Affecting Accuracy of MOLLI T1 Values

Kelvin Chow¹, Joseph J. Pagano¹, Richard B. Thompson¹

The MOLLI sequence commonly used for myocardial T₁ quantification is known to have systematic errors dependent on T₁ and T₂ values, although the interaction of these effects is not well understood. We propose an intuitive model for predicting MOLLI errors based on the magnetization perturbation of the imaging readout (M_diff), incorporating the effects of tissue relaxation and other sequence parameters. Experiments in phantoms show highly variable MOLLI accuracy that is strongly correlated with M_diff, due to varying magnetization perturbation caused by different T₂/T₁ values. Common sequence parameter changes also alter MOLLI accuracy in a way predicted by the M_diff model.