Balanced left ventricular myocardial SSFP-tagging at 1.5T and 3T

The purpose of the study was to evaluate the performance of steady-state free precession (SSFP)-tagging at 1.5T and 3T and to define the ideal settings with respect to optimized tag contrast throughout the cardiac cycle for both field strengths. To identify optimal imaging parameters data acquisition was repeated for different flip angles. Left ventricular tag-tissue contrast, tag fading times, tag persistence, and myocardial signal-to-noise ratio (SNR) were quantified in basal, mid-ventricular, and apical slice locations. To assess the effect of field strength on image quality and artifact level, additional semiquantitative image grading was performed by two experienced readers. SSFP-tagging at 3T proved superior to 1.5T and provided significantly enhanced tag persistence and myocardial SNR while maintaining overall image quality and artifact level. The definition of a tag quality index demonstrated optimal SSFP-tagging performance for a flip angle of 20 degrees. Diastolic tag visibility was improved at 3T and resulted in enhanced average tag persistence of 789 +/- 128 ms compared to 523 +/- 40 ms at 1.5T. For SSFP-tagging at 3T the combination of T-1 lengthening and superior myocardial SNR is highly promising and has the potential to improve the depiction of tagged myocardial function throughout the entire cardiac cycle.