ASSESSMENT OF NORMAL FLOW VELOCITY IN BASAL CEREBRAL VEINS - A TRANSCRANIAL DOPPLER ULTRASOUND STUDY

Background and Purpose Transcranial Doppler ultrasound has not yet bee n applied systematically to the analysis of the venous system and cere brovenous disorders. Assessment of the intracranial venous system, how ever, would contribute to the understanding of cerebral hemodynamics a nd thus allow new possibilities for clinical application of the Dopple r technique. Therefore, we demonstrated the validity of the transcrani al Doppler technique in analyzing the basal cerebral veins. Methods Ve nous 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 bas al 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 v alues with increasing age, exclusively caused by a significant reducti on of velocity in men aged 40 years or older. No significant intraindi vidual side-to-side differences were found. A venous signal away from the probe and paralleling the middle cerebral artery, interpreted as c orresponding to the deep middle cerebral vein, was found in 21.7% of t he subjects with similar velocities. Conclusions We have shown that tr anscranial Doppler methods can also be used for evaluation of the basa l cerebral veins in both sexes, in differing age groups, and without m ajor difficulty. The cerebral basal veins could be identified on the b asis of their anatomic relation to specific arteries.