Effect of age on cerebral blood flow: Measurement with ungated two-dimensional phase-contrast MR angiography in 250 adults

PURPOSE: To determine the normal values and effects of age and sex on total cerebral blood flow (CBF) as measured with ungated two-dimensional phase-contrast magnetic resonance (MR) angiography. MATERIALS AND METHODS: Volume flow rates in the basilar artery and both internal carotid arteries were measured on two-dimensional phase-contrast MR angiograms obtained in 250 subjects(age range, 19-88 years; mean age, 50 years) undergoing MR imaging because of indications other than cerebrovascular disease. Volume flow rates for-the th ree arteries were sum med to obtain the total CBF, and the values were analyzed in terms of age and sex. RESULTS: Mean total CBF was 616 mL/min +/- 143. There was a significant yearly decrease with age in total CBF of 4.8 mL/min (P < .001). Mean total CBF ranged from 748 mL/min +/- 121 to 474 mL/min +/- 105 in subjects aged 19-29 and 80-89 years respectively. No sex differences were found. Mean relative contributions of the right and left internal carotid arteries and the basilar artery to total CBF were 41%, 40% and 19%, respectively, with no substantial change due to age. CONCLUSION: Ungated two-dimensional phase-contrast MR angiography is a useful, noninvasive technique for assessing total CBF. By using this technique, a significant decrease in total CBF with age was demonstrated.