Clinical question: R hemiparesis s/p R + L vert clipping / sacrifice for basilar fusiform aneurysmSigns and Symptoms: R hemiparesis s/p R + L vert clipping / sacrifice for basilar fusiform aneurysm MRI of the brainThere are several millimeter sized foci of diffusion restriction in the left inferior cerebellum and the left inferior tip of the vermis. No diffusion weighted abnormalities are appreciated in the medulla. However, artifact from the clips obscures visualization immediately adjacent to the clips.On T2 imaging there is a subtle 5mm focus of mild signal hyperintensity along the left posterior aspect of the medulla at the expected location of the left hypoglossal nucleus and left nucleus intercalatus.The flow voids of the intracranial vertebral arteries are not present. The proximal portion of the fusiform basilar aneurysm has heterogeneous but relatively high signal on T2 and intermediate signal on T1. The mid portion and superior portions of the aneurysm have a combination of signal void and T1 and T2 signal hyperintensity.There is artifact on T2 and FLAIR MRI overlying the lower pons suspected to be a result of the metallic clips.The patient is status post distal vertebral artery clipping with suboccipital craniotomy and C1 laminectomy.The CSF spaces are appropriate for the patient's stated age with no midline shift. Normal vascular flow voids are present in the distal carotid arteries and the proximal anterior, middle and posterior cerebral arteries as well as the internal cerebral veins and superior sagittal sinus.The visualized portions of the paranasal sinuses are clear. The visualized portions of the mastoid air cells are clear. The visualized portions of the orbits are intact.MRA brain:Artifact obscures visualization of the distal vertebral arteries and the proximal left PICA. A small portion of the right vertebral artery and right PICA can be subtly but questionably discerned.Bilateral PICA cannot be identified. Portions of the right and left AICA are identified. The distal basilar artery opacify.Antegrade flow is present in the distal internal carotid arteries, the basilar artery and the proximal anterior, middle and posterior cerebral arteries.The anterior communicating artery is identified. The posterior communicating arteries are not readily identified. The vertebral arteries are similar in size.
1.There are several punctate foci of microinfarction in the left inferior cerebellum. There is no convincing evidence for cerebral infarction involving the brainstem, however, part of the medulla is obscured by artifact. There is, however, some signal change in the posterior aspect of the left medulla which may represent ischemic damage involving the area of hypoglossal nucleus and nucleus intercalatus. This would not explain right hemiparesis, however. Please note that metal artifact may obscure or exaggerate visualization of subtle findings in the territories adjacent to the metal clips.2.The aneurysm, AICA, PICA and distal vertebral arteries may be better evaluated on a contrast enhanced imaging study such as a CTA. Metal artifacts and slowed flow in patulous vessels may obscure visualization on this 3DTOF1.5 T MRA. As a result interpretation as to the status of these vessels on 3DTOF1.5T MRA may be limited. 3.Findings were discussed with Dr Awad at the time of the exam.4.Status post distal vertebral artery clipping with suboccipital craniotomy and C1 laminectomy.