Flow velocity and flow volume measurements in the extracranial carotid andvertebral arteries in healthy adults: Reference data and the effects of age

To establish reference data and to investigate the development of haemodyna mics in the extracranial carotid and vertebral arteries, we performed a pro spective study in 78 age- and gender-matched healthy adults from 20 to 85 y old. Angle-corrected flow velocities and luminal diameters were measured a nd waveform parameters and flow volumes calculated in all the arteries. Sid e-to-side differences and the influence of age on these parameters were als o investigated. In the common carotid arteries, the internal carotid arteri es and the vertebral arteries (CCA, ICA and VA, respectively) all flow velo cities decreased significantly during ageing. The luminal diameter remained constant in all the carotid arteries, but increased slightly with age in t he VA. An age-related decline of intravascular flow volume was observed in the ICA. Due to a pronounced decrease in end-diastolic flow velocity, the r esistance index decreased in ICA and VA during ageing. There were no signif icant side-to-side differences in how velocities and flow volumes in any of the extracranial arteries. The luminal diameters of the CCA, ICA and ECA w ere significantly smaller in women than in men. No relevant gender-related differences in flow velocities or waveform parameters were found in the ext racranial arteries. There was no gender-linked difference in the flow volum es of the brain-feeding arteries and, in the EGA, flow volumes were signifi cantly higher in men. Reference data on all how velocities and waveform par ameters, luminal diameters and flow volumes were established for different age groups between 20 and 85 y old. These data allow us to outline the deve lopment of cerebral haemodynamics during "benign ageing" and to utilise flo w volume measurements in clinical practice, especially in patients with cer ebrovascular diseases. (C) 2000 World Federation for Ultrasound in Medicine & Biology.