Reason: eval for stroke L sided hemiparesis and dizziness History: stroke w/u: assess for LV thrombus, wall motion abnormalities, PFO, valvular disease MRI brain:Punctate focus of increased DWI signal in the right anterior medulla is suspicious for an acute infarct. There is minimal associated increased FLAIR signal. A few scattered subcortical T2 hyperintensities within the supratentorial white matter are nonspecific but may reflect chronic small vessel ischemic disease. Multiple T2 hyperintensities without diffusion restriction or FLAIR abnormality in the bilateral cerebellum, with a left cerebellar lesion corresponding to prominent finding seen on prior CT likely represent old lacunar infarcts..There is no evidence of intracranial hemorrhage or mass. Ventricles and sulci are slightly prominent, suggesting a mild degree of volume loss. There is no midline shift or herniation. There is an absent flow void in the right vertebral artery. The orbits, skull and scalp soft tissues are grossly unremarkable. The paranasal sinuses are unremarkable.MRA brain and neck:There is a separate origin of the left subclavian artery, left common carotid artery, and brachiocephalic artery from the arch. The common carotid arteries and cervical internal carotid arteries are patent with mild narrowing at the bifurcations, left greater than right. The intracranial internal carotid arteries are normal in course and caliber. The right A1 segment is hypoplastic with fetal type posterior cerebral arteries bilaterally. The middle and anterior cerebral arteries are otherwise unremarkable without evidence of stenosis or aneurysm.The basilar artery is severely narrowed and not visualized throughout its majority, either high-grade stenosis or occlusion. The distal V4 segment of the left vertebral is small in caliber. The left vertebral artery overall is diminutive in caliber at the V1 and V2 levels. At the V3 and proximal V4 level, the left vertebral is not visualized. The left vertebral origin is also not well visualized The right vertebral is not visualized throughout its course. Overall this suggests severe vertebrobasilar insufficiency with areas of high-grade stenosis and/or occlusion.
1.Focus of diffusion restriction in the right medulla is suspicious for an acute infarct.2.Severe vertebrobasilar narrowing including nonvisualization of the entire right vertebral artery, diminutive left vertebral artery with nonvisualization of the V3 and proximal V4 segments with likely collateralized flow accounting for visualized but diminutive V1 and V2 segments, and diminutive basilar artery with a substantial portion nonvisualized. Evaluation limited due to lack of contrast enhanced MRA neck. Overall this may represent areas of high degree stenosis and/or occlusion. These findings are likely chronic and may include underlying dissection, and CTA may be helpful for further characterization.3.A few subcortical T2 hyperintensities are nonspecific but likely represent chronic small vessel ischemic disease.4.Multiple bilateral lacunar infarcts of the cerebellum.