Left-sided ataxia. Posterior circulation stroke. Study is mildly limited by patient motion.BRAIN MRI: There is a wedge-shaped area of diffusion restriction and T1-hypointense/T2-hyperintense signal involving the superior aspect of the left cerebellar hemisphere and the left superior cerebellar peduncle and left posterolateral aspect midbrain, with associated mild swelling causing very minimal mass-effect on the fourth ventricle. This is associated with mild, heterogeneous contrast enhancement reflecting the subacute nature of the infarct. Otherwise, there is encephalomalacia in the lateral left occipital lobe extending into the inferior part of the left parietal lobe, with associated ex vacuo enlargement of the left lateral ventricular occipital horn. There are punctate foci of susceptibility effect within these infarcts which probably reflect mineral deposition or minimal hemorrhage. There are also multiple small CSF intensity lesions in the basal ganglia and in the left subinsular region, compatible with chronic infarcts. There is also moderate periventricular and deep T2-hyperintense lesions, which most likely represent chronic microvascular ischemia, superimposed on moderate brain volume loss. There is no midline shift or brain herniation. Caval septum pellucidum and cavum vergae noted and common incidental findings. There is trace mucosal thickening the paranasal sinuses. There is no gross orbital abnormality. There is no destructive skull lesion.CRANIAL MRA:There is moderate narrowing of the terminal part of right V4 segment and mild narrowing involving the mid left V4 segment and distal basilar artery. The left posterior cerebral artery is mildly attenuated. The right A1 segment is hypoplastic. Otherwise, the anterior circulation shows mild irregularity from mild atherosclerosis but no large vessel occlusion. NECK MRA:Accounting for limitation caused by patient motion, there is no significant, flow-limiting stenosis or occlusion of the cervical carotid arteries or vertebral arteries. However, the origin of the right vertebral artery is suboptimally assessed. Also an apparent severe stenosis involving the mid right V2 segment at C4-C5 level is probably artifactual. Otherwise, the vertebral arteries are mildly irregular, reflective of mild atherosclerosis. There are tiny thyroid nodules, the largest measuring up to 4 mm in the right lobe.
1.Acute to subacute left cerebellar infarct in the territory of the superior cerebellar artery, associated with only minimal mass-effect.2.Chronic left occipital infarct with punctate foci of hemorrhage or mineral deposition. Moderate chronic cerebral white-matter microvascular ischemia and moderate global brain volume loss.3.There is moderate narrowing of the terminal right V4 segment. Otherwise, there is mild atherosclerotic involvement of the intracranial arteries but no large vessel occlusion. Specifically, the superior, anterior inferior and posterior inferior cerebellar arteries are visualized bilaterally.4.Vertebral arteries in the neck are suboptimally evaluated. There is at least mild atherosclerotic disease involving the vertebral arteries in the neck. No long segment occlusion. Repeat MRA neck or CTA can be considered as clinically indicated. No significant stenosis involving the common or internal carotid arteries. 