Transcranial color Doppler sonography of basal cerebral arteries in 182 healthy subjects: Age and sex variability and normal reference values for blood flow parameters

OBJECTIVE. Only a limited number of transcranial color-coded Doppler studie s have provided ranges for the normal reference values of cerebral hemodyna mic parameters. These reports are not fully convergent in relation to the r ange of values or to the age and sex dependence of blood how parameters. Th e aim of the present study was to provide data regarding normal reference r anges. SUBJECTS AND METHODS. We examined 182 healthy volunteers (79 men and 103 wo men; age range, 20-86 years old) with color-coded Doppler sonography via a temporal acoustic window with a 2.5-MHz transcranial probe. The subjects we re divided into three age groups: 20-40 years old (group 1), 41-60 years ol d (group 2), and more than 60 years old (group 3). Angle-corrected peak sys tolic, end-diastolic, and mean Velocities as well as impedance indexes were determined in anterior, middle, and posterior cerebral arteries. RESULTS. Mean velocity values for middle, anterior, and posterior cerebral arteries in age group I were 81 +/- 20, 56 +/- 14, and 52 +/- 12 cm/sec (me an +/- SD), respectively. In group 2, the values were 73 +/- 19, 53 +/- 16, and 51 +/- 12 cm/sec (mean +/- SD), and in group 3, the values were 59 +/- 11, 44 +/- 11, and 40 +/- 9 cm/sec (mean +/- SD). Decrease in blood flow v elocities and a concomitant increase in impedance indexes were found in all vessels with advancing age-findings that were most pronounced in subjects who were more than 40 years old. In the 20- to 40-year-old group, mean velo cities for all vessels were higher in women than in men, whereas impedance indexes were not significantly different. CONCLUSION. Flow velocities in basal cerebral arteries range widely and are significantly age dependent. Age and sex matching of Doppler sonographic d ata is a prerequisite for clinically valuable conclusions.