Male, 18 years old, with history of sickle cell disease and old infarct on CT. Assess for areas of ischemia, evidence of new or old infarcts. MRI:Foci of T2 hyperintensity are again seen along the perfusional watershed region of the deep right cerebral white matter. Small foci of T2 hyperintensity and/or encephalomalacia are also demonstrated along the right caudate nucleus, unchanged. A 5 mm non specific focus of T2 hyperintensity within the left temporal lobe just lateral to the temporal horn is new or larger compared to the prior examination. No restricted diffusion is seen to suggest acute ischemia.The cerebellar tonsils are pointed and descends 7-8 mm below the level of the foramen magnum. There is significant crowding of the CSF space at the level of the foramen magnum. Platybasia is demonstrated. Also seen is progressive expansion of the calvarial marrow space likely related to sickle cell disease.No evidence of parenchymal edema or mass effect is seen. No intracranial hemorrhage or any abnormal extra axial fluid collection is detected. The ventricular system is normal in size and morphology. On postcontrast images, no pathologic parenchymal or extra-axial enhancement is detected.The right periorbital soft tissues are mildly edematous.MRA:Normal flow related signal is seen within the anterior and posterior circulations. No evidence of significant vascular stenosis or occlusion is seen. A complete circle of Willis is evident with prominent ACOM and PCOM arteries.
1.No evidence of acute ischemia or any other definite acute intracranial abnormality.2.Small lesions are seen most likely representing chronic ischemia along the perfusional watershed of the deep right cerebral white matter, and within the right caudate nucleus. A subtle focus of signal abnormality within the left temporal lobe is nonspecific.3.Findings compatible with Chiari malformation are demonstrated.4.Unremarkable MRA of the brain.