<prompt> True about radiological features of Neurofibromatosis type 1 is all except:Dural ectasiasEmpty orbit signEncephalotrigeminal angiomatosisSuperior rib notching  <response>: Ans. C. Encephalotrigeminal angiomatosisEncephalotrigeminal angiomatosis is synonymous with Sturge Weber syndrome, which is characterized by venous angiomas, Port wine stain and tram track gyral calcification in cerebrum. 