Change in Cerebral Perfusion Detected by Dynamic Susceptibility Contrast Magnetic Resonance Imaging: Normal Volunteers Examined During Normal Breathing and Hyperventilation

Cerebral perfusion parameters were measured using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) in eight healthy volunteers examined during normal breathing and spontaneous hyperventilation. DSC-MRI-based cerebral blood flow (CBF) decreased during hyperventilation in all volunteers (average decrease 29%), and the corresponding global CBF estimates were 73 plusmn 19 ml/(min 100 g) during normal breathing and 52 plusmn 7.9 ml/(min 100 g) during hyperventilation (mean plusmn SD, n = 8). Furthermore, the hypocapnic conditions induced by hyperventilation resulted in a prolongation of the mean transit time (MTT) by on average 13%. The observed CBF estimates appeared to be systematically overestimated, in accordance with previously published DSC-MRI results, but reduced to more reasonable levels when a previously retrieved calibration factor was applied.