Doppler sonography evaluation of flow velocity and volume of the extracranial internal carotid and vertebral arteries in healthy adults.

PURPOSE

To measure with Doppler sonography the velocity and volume of blood flow in the extracranial internal carotid artery (ICA) and vertebral artery (VA) of healthy adults and to calculate total cerebral blood flow volume (tCBFV).

METHODS

Bilateral ICA and VA were examined sonographically in 180 healthy adults. Angle-corrected peak systolic (Vps), end-diastolic (Ved), and time-averaged maximum blood flow velocity (TAV) were measured in pulsed Doppler mode, and the resistance index (RI) and pulsatility index (PI) were calculated. The cross-sectional area (A) was measured on gray-scale images. Volume flow was calculated as FV = TAV x A, and tCBFV was calculated as the sum of the right and left ICA and VA volume flow.

RESULTS

tCBFV was 651 +/- 96 ml/min for the entire population. There was a significant decrease in Vps, Ved, TAV, and tCBFV with age in all arteries. RI and PI values initially declined and then increased with age. Cross-sectional area increased with age in ICA but not in VA. PI and RI were higher in men than in women. Blood flow velocity and volume were higher, and RI was lower in the left than in the right VA.

CONCLUSION

The Doppler sonographic assessment of extracranial ICA and VA blood flow volume may be useful for the study of cerebral hemodynamic changes in patients with cerebrovascular disorders. Age-dependent changes should be considered, for instance, in the management of intensive care patients with impaired cerebral perfusion.