Comparison of simultaneously measured perfusion and bold signal increases during brain activation with T1-based tissue identification

Abstract

Perfusion and blood oxygenation level-dependent (BOLD) signals were simultaneously measured during a finger-tapping task at 3T using QUIPSS II with thin-slice TI1 periodic saturation, a modified pulsed arterial spin labeling technique that provides quantitative measurement of perfusion. Perfusion and BOLD signal changes due to motor activation were obtained and correlated with the T1 values estimated from echo-planar imaging (EPI)-based T1 maps on a voxel-by-voxel basis. The peak perfusion signal occurs in voxels with a T1 of brain parenchyma while the peak BOLD signal occurs in voxels with a T11 characteristic of blood and cerebrospinal fluid. The locations of the peak signals of functional BOLD and perfusion only partially overlap on the order of 40%. Perfusion activation maps will likely represent the sites of neuronal activity better than do BOLD activation maps. (C) 2000 Wiley-Liss, Inc.