Age dependence of cerebral perfusion assessed by magnetic resonance continuous arterial spin labeling

PURPOSE: To study the normal dependence of cerebral perfusion changes on age, to measure values of perfusion early in life, and to create a reference dataset. MATERIALS AND METHODS: Perfusion maps were collected from a total of 44 healthy subjects (from four to 78 years old) using the arterial spin labeling (ASL) technique. The population was retrospectively divided into three age groups: children, teenagers, and adults. For each group, mean values of cerebral blood flow (CBF) were calculated in gray matter (GM) and white matter (WM). Results were compared across the three different age groups. RESULTS: CBF values decreased with age (97+/-5 mL/100 g/minute in GM and 26+/-1 mL/100 g/minute in WM for the children, GM 79+/-3 mL/100 g/minute and WM 22+/-1 mL/100 g/minute for the teenagers, and GM 58+/-4 mL/100 g/minute, WM 20+/-1 mL/100 g/minute for the adults). The quantitative results suggest a rapid drop, rather than a gradual decrease, in cerebral perfusion between children and adult subjects, especially in the GM. This step in CBF occurs during adolescence, at approximately the 16th year of age. CONCLUSION: ASL is a practical and quantitative technique suitable for perfusion measurement in children as well as adults. Perfusion measurements with ASL appear sensitive to neurophysiological changes occurring during brain maturation.