Autism and global developmental delay: assess myelination. The third and lateral ventricles are mildly prominent due to apparent mild deficiency of white matter bulk diffusely. However there is complete myelination of supratentorial and infratentorial white matter. There is a 10 mm wide arachnoid cyst overlying the anteromedial aspect of the left temporal pole. Otherwise, there is no evidence of intracranial hemorrhage, mass, or acute infarct. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull, mastoid air cells, and scalp soft tissues are grossly unremarkable. There is mild diffuse paranasal sinus mucosal thickening.
1. The third and lateral ventricles are mildly prominent due to apparent mild deficiency of white matter bulk diffusely. However there is complete myelination of supratentorial and infratentorial white matter. 2. Small arachnoid cyst overlying the anteromedial aspect of the left temporal pole. 