PURPOSE
To determine the direction of blood flow in the circle of Willis using a 3-D phase contrast MR angiographic (MRA) technique with high spatial resolution.
SUBJECTS
Fifty healthy subjects and 15 patients with occlusive disease were studied using 3-D phase contrast MRA.
RESULTS
In the 50 normal subjects, 39 (78%) had detectable flow in one or both posterior communicating arteries. In 2...
