 The aortic arch demonstrates conventional anatomy. There origins of the bilateral vertebral arteries are patent. There is no evidence of flow-limiting stenosis or aneurysm involving the vertebral or basilar arteries. There is high-grade stenosis of the left superior cerebellar artery approximately 1 cm beyond its origin. There is atherosclerotic calcification at the bilateral carotid artery bifurcations without evidence of significant stenosis.
High-grade stenosis of the left superior cerebellar artery approximately 1 cm beyond its origin. The vertebral and basilar arteries are patent without evidence of flow-limiting stenosis or aneurysm. 