DURAL ECTASIA OF THE OPTIC-NERVE SHEATH IN NEUROFIBROMATOSIS TYPE-1 -CT AND MR FEATURES

Objective: Optic nerve glioma is a common finding in patients with neu rofibromatosis type 1 (NF-1). Although dural ectasia of the optic nerv e is encountered rarely, it has to be considered in the differential d iagnosis. Materials and Methods: Three patients affected by NF-1 were examined sequentially by CT and MRI. Results: Computed tomography demo nstrated nonprogressing enlargement of the anterior optic pathways. Ma gnetic resonance imaging displayed widening of the perioptic dural she ath without any suggestion of tumor. Conclusion: These findings are co mpatible with meningocele or dural ectasia of the optic nerve sheath. This entity represents a differential diagnosis to optic glioma in pat ients with NF-1.