"Doppler Flow Velocity Measurements in the Extracranial Internal Carotid and Vertebral Arteries in Healthy Adults"

Abstract

Objective: To analyze normal hemodynamics in the extracranial part of the internal carotid arteries (ICA) and vertebral arteries (VA) with reference to age and gender. Methods: Angle-corrected flow velocities (peak-systolic velocity, PSV and end-diastolic velocity, EDV) and VA diameter were measured, and waveform parameters calculated (pulsatility index, PI and resistive index, RI) on 227 healthy adults (125 women). Results: Except for a slight increase of PSV in the left VA in men, and wider left VA diameter in both genders, there were no clinically significant side-to-side differences in the investigated parameters. In 10-year periods, expected decreases in PSV ICA, EDV ICA, PSV VA, and EDV VA were 3-3.7, 2.2-2.8, 0.6-1.5, and 0.7-1 cm/s, respectively while expected increases in RI ICA, PI ICA, RI VA, PI VA, and VA diameter were small, in a range of 0.01-0.07. Average velocities were higher in women up to 60 years on both sides in ICA and VA. In the women, expected values of PSV ICA, EDV ICA, PSV VA, and EDV VA were 5.9-6.2, 1.9-2.2, 2.1-4.3, and 1 cm/s, respectively, i.e., higher than in the men. PI and RI showed no association with gender. Measurements showed that PSV ICA, EDV ICA, PSV VA, and EDV VA ranged 40-108, 10-39, 24-63, 2-22 cm/s in women and 35-114, 7-36, 24-66, and 5-18 cm/s in men, respectively. RI ICA, PI ICA, RI VA, PI VA, and VA diameter were in the ranges 0.5-0.8, 0.9-1.9, 0.6-21, 1.1-24, and 1.4-4.9 in women; 0.5-0.9, 0.8-2.1, 0.6-0.9, 1.1-2 mm, and 2.1-5.3 mm in men, respectively. Conclusion: Velocity was higher in the women up to 60 years. In older age groups the flow rates equalized in both genders. EDV ICA decreased with age in both genders. PSV ICA showed a declining trend only in women. RIs and PIs showed a slight tendency to increase with age in both genders. In the vertebral arteries, a slight tendency to decreased flow velocities with age was seen mostly in EDV in both genders, whereas PSV showed decline and diameter increase only in women.