Diffuse and severe narrowings are demonstrate at bilateral anterior cerebral and middle cerebral arteries and their branches. Multiple anastomoses are demonstrated between the posterior and anterior and middle cerebral arteries via leptomeningeal arteries. Similarly, anastomoses are demonstrated between the left external and left internal carotid vessels. A small, 1.2 x 1.3 cm aneurysm is demonstrated at the distal right anterior choroidal artery. This correlates with the distribution of blood demonstrated on the CT Brain. Multiple small vessels are demonstrated at bilateral lenticulo-striate territories. No definite evidence of further aneurysms. Bilateral foetal posterior communication arteries identified. Moderate fibromuscular dysplasia noted at the left internal carotid artery.
Conclusion: Changes are consistent with moya-moya disease and right distal anterior choroidal artery aneurysm.