title: Optic nerve atrophy and CT scanning: the target sign.
abstract: Three patients are described who demonstrate the "target-sign" of optic nerve atrophy on CT scanning. This sign is produced by the centrally located atrophic optic nerve surrounded by a patulous perioptic subarachnoid space. An explanation for this phenomenon is proposed.
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009896:Optic Atrophy / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed