Female, 12 years old, with altered mental status and history of sickle cell disease. Evaluate for infection or stroke. Numerous foci of restricted diffusion are seen ranging in size from punctate up to about 5 mm and distributed predominantly within the watershed zones of the bilateral cerebral hemispheres.These lesions are associated with minimal corresponding T2 hyperintensity, but no significant 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, there is prominent sulcal enhancement with subtle corresponding FLAIR hyperintensity which may reflect stagnant flow, vascular collateralization or leptomeningeal inflammation.MRA images demonstrate attenuation of flow related signal within the ICAs bilaterally, both at the level of the anterior genu and at the A1/M1 junctions. Distally, the visualized intracranial vessels demonstrate normal caliber. No specific abnormalities are detected within the posterior circulation.
1. Numerous small scattered acute strokes are seen within the watershed zones of the cerebral hemispheres. These result in no significant parenchymal edema or mass effect.2. Diffuse cerebral sulcal enhancement is seen, a nonspecific finding which, given the above findings, may reflect slow flow or vascular collateralization. However, this could also reflect leptomeningeal inflammation or infection in the appropriate clinical context.3. MRA imaging of the intracranial vessels demonstrates apparent attenuation of flow related signal within the distal ICAs. Such findings can sometimes arise as a result of an imaging artifact. However, given the presence of ischemic lesions, the possibility of true vascular narrowing, as in an early moyamoya phenomenon, should also be considered.