Phasic variations in T2 relaxation times of myocardium

Differences in myocardial T2 measurements may be due to the technique of data acquisition or to a phasic variation in the values related to the cardiac cycle. The latter may provide an estimate of myocardial contractility. Ten healthy subjects were studied on three occasions with a 0.5-T MR imaging unit. T2 values were calculated using two echoes on a single sequence and using offset first-echo images from two successive sequences. The T2 values derived from the single sequence were more accurate and reproducible. T2 values at end-diastole were about 10% longer than at end-systole. This was true for all parts of the myocardium