IN-VIVO MULTIPLE SPIN ECHOES

The demagnetizing field produced by the nuclear polarization can induc e refocusing of multiple spin echoes. We show that multiple spin echoe s can be observed in vivo with a clinical MR system at 1.5 T. Strategi es for the spatial localization of the multiple spin echo signals are considered. Multiple spin echo studies in brain white matter and skele tal muscle in healthy volunteers are reported. The dependence of the s ignal amplitudes on the experimental parameters is compared with the t heory. The sources of contrast for MRI and the perspectives for medica l applications are discussed. (C) 1998 Academic Press.