CT skull giving tram track appearance is diagnostic of-

Ans is 'd' i.e. Sturge Weber syndrome * CT scans in Sturge Weber syndrome show the tramline gyriform calcification of apposing gyri that underlies the contrast-enhancing leptomeningeal vascular malformation.Other CT scan findings Sturge Weber syndrome* Cortical atrophy* Abnormal draining veins* Enlarged choroid plexus* Blood-brain barrier breakdown (during seizures)* Contrast enhancement