Perfusion MRI of the human brain with dynamic susceptibility contrast: Gradient-echo versus spin-echo techniques

In this study, spin-echo and gradient-echo-based perfusion magnetic resonan ce imaging (MRI) techniques are systematically compared with respect to the ir application in the human brain. Six healthy subjects were evaluated with both techniques consecutively and injected twice with a gadolinium-based c ontrast agent. in accordance with theoretical predictions and with previous animal experiments, the spin-echo-based technique shows a markedly reduced appearance of large vessels. The intersubject standard deviations of the t wo methods are similar but smaller for the spin-echo technique in small reg ions adjacent to large vessels. Therefore, the sensitivity of the two acqui sition methods for evaluating pathologic abnormalities may be similar despi te the higher contrast-to-noise ratio of the gradient-echo-based technique. The gray-to-white matter ratio of the regional cerebral blood flow of the spin-echo method Is closer to previous nuclear medicine measurements than t hat of the gradient-echo method. Our measurements indicate that spin-echo-b ased perfusion MRI is more representative of capillary perfusion than gradi ent-echo measurements. (C) 2000 Wiley-Liss, Inc.