Assessment of Normal Flow Velocity in Basal Cerebral Veins

Background and Purpose Transcranial Doppler ultrasound has not yet been applied systematically to the analysis of the venous system and cerebrovenous disorders. Assessment of the intracranial venous system, however, would contribute to the understanding of cerebral hemodynamics and thus allow new possibilities for clinical application of the Doppler technique. Therefore, we demonstrated the validity of the transcranial Doppler technique in analyzing the basal cerebral veins. Methods Venous transcranial Doppler ultrasound was performed with a range-gated 2-MHz transducer in 60 healthy volunteers and patients without central nervous disorders ranging in age from 10 to 71 years (mean±SD, 41.9±15 years). Results A venous signal away from the probe and adjacent to the posterior cerebral artery, considered to correspond to the basal vein of Rosenthal, was found in all subjects on at least one side. Mean blood flow velocity ranged from 4 to 17 cm/s (mean±SD, 10.1±2.3 cm/s). Analysis for age dependency revealed a trend of decreasing values with increasing age, exclusively caused by a significant reduction of velocity in men aged 40 years or older. No significant intraindividual side-to-side differences were found. A venous signal away from the probe and paralleling the middle cerebral artery, interpreted as corresponding to the deep middle cerebral vein, was found in 21.7% of the subjects with similar velocities. Conclusions We have shown that transcranial Doppler methods can also be used for evaluation of the basal cerebral veins in both sexes, in differing age groups, and without major difficulty. The cerebral basal veins could be identified on the basis of their anatomic relation to specific arteries.