Saturation Recovery Single-Shot Acquisition (SASHA) for Myocardial T1 Mapping

PurposeTo validate a new saturation recovery single-shot acquisition (SASHA) pulse sequence for T-1 mapping and to compare SASHA T-1 values in heart failure patients and healthy controls. TheoryThe SASHA sequence consists of 10 electrocardiogram-triggered single-shot balanced steady-state free precession images in a breath-hold. The first image is acquired without magnetization preparation and the remaining nine images follow saturation pulses with variable saturation recovery times. MethodsSASHA was validated through Bloch equation simulations, Monte Carlo simulations, and phantom experiments. Pre- and postcontrast myocardial and blood T-1 values were measured in 29 healthy volunteers and 7 patients with heart failure. ResultsSASHA T-1 values had excellent agreement (bias, 5 5 ms) with spin echo experiments in phantoms with a wide range of physiologic T-1 and T-2 values and its accuracy was independent of flip angle, absolute T-1, T-2, and heart rate. The average baseline myocardial T-1 in heart failure patients was higher than in healthy controls (1200 +/- 32 vs. 1170 +/- 9 ms, P < 0.05) at 1.5T, as was the calculated blood-tissue partition coefficient, , (0.42 +/- 0.04 vs. 0.38 +/- 0.02, P < 0.05), consistent with diffuse myocardial fibrosis. ConclusionsThe SASHA sequence is a simple and fast approach to in vivo T-1 mapping with good accuracy in simulations and phantom experiments. Magn Reson Med 71:2082-2095, 2014. (c) 2013 Wiley Periodicals, Inc.