Sturge-Weber syndrome, or encephalotrigeminal angiomatosis, is a phacomatosis characterized by facial port wine stains and pial angiomas. 

CT findings:

• detects subcortical calcification at an earlier age than plain film and can also demonstrate associated parenchymal volume loss
• tram-track sign of cortical and subcortical calcification ^1,2
• calvarial and regional sinus enlargement may be evident
• ipsilateral choroid plexus may be enlarged
• in severe cases, a Dyke-Davidoff-Masson appearance may be seen
• orbital choroidal hemangiomas may be present
• asymmetric cavernous sinus enlargement ³