Quantification of dynamic changes in cerebral venous oxygenation with MR phase imaging at 1.9 T

A double-echo magnetic resonance (MR) phase imaging method was used to meas ure the time-dependent changes in regional cerebral venous blood oxygenatio n during neural stimulation. Our results showed that a finger opposition ta sk induced an absolute increase of blood oxygenation level of Delta Y = 0.1 6 +/- 0.05 (n = 6), which was measured in the small veins located in the le ft central sulcus. It was observed that there is a long temporal delay of a pproximately 27 sec after the onset of the task to reach the steady-state v enous oxygenation. This work demonstrated that MRI is a powerful clinical t ool for in vivo monitoring of the dynamic nature of organ-specific venous b lood oxygenation. (C) 1999 Wiley-Liss, Inc.