Arrhythmia Insensitive Rapid Cardiac T1 Mapping Pulse Sequence

PurposeTo develop an arrhythmia-insensitive rapid (AIR) cardiac T-1 mapping pulse sequence for quantification of diffuse fibrosis. MethodsAn arrhythmia-insensitive cardiac T-1 mapping pulse sequence was developed based on saturation recovery T-1 weighting, which is inherently insensitive to heart rate and rhythm, and two single-shot balanced steady-state free precession image acquisitions with centric k-space ordering, where T-1 calculation is inherently insensitive to T-2 effects. Its performance against conventional cardiac T-1 mapping based on inversion recovery (i.e., MOLLI) is compared. Phantom experiments (T-1 ranging from 535 to 2123 ms) were performed with heart rate and rhythm simulated at 60 and 120 beats per minute (bpm) and arrhythmia using an external triggering device. Ten human subjects and 17 large animals were scanned precontrast and 5, 10, and 15 min after contrast agent administration. ResultsCompared with the reference T-1 mapping, AIR yielded lower normalized root-mean-square error than MOLLI (8% vs. 3%, respectively, at 60 bpm, 28% vs. 3%, respectively, at 120 bpm, and 22% vs. 3%, respectively, at arrhythmia). In vivo studies showed that T-1 measurements made by MOLLI and AIR were strongly correlated (r = 0.99) but in poor agreement (mean difference = 161.8 ms, upper and lower 95% limits of agreements = 347.5 ms and -24.0 ms). ConclusionOur AIR pulse sequence may be clinically useful for assessment of diffuse myocardial fibrosis in patients. Magn Reson Med 70:1274-1282, 2013. (c) 2012 Wiley Periodicals, Inc.