Evaluation of sodium T1 relaxation times in human heart

Purpose To evaluate the sodium longitudinal relaxation (T1) characteristics for myocardium and blood in humans. Materials and Methods Eleven healthy volunteers were examined by using a 23Na heart surface coil at a 1.5 T clinical scanner equipped with a broadband spectroscopy option. 23Na MR measurements were performed by using a three-dimensional spoiled gradient echo sequence (in-plane resolution, 3.5 mm × 7 mm; slice thickness, 24 mm; TE, 3.1 msec; bandwidth, 65 Hz/pixel; TR, 21 to 150 msec). Results Longitudinal T1 relaxation time components were 31.6±7.0 msec and 31.1±7.5 msec for myocardium and blood, respectively. Conclusion 23Na T1 relaxation times of myocardium and blood can be determined in humans. The results are in agreement with values obtained from animal studies. J. Magn. Reson. Imaging 2003;17:726–729. © 2003 Wiley-Liss, Inc.