title: Computed tomography in the evaluation of the optic chiasm.
abstract: Computed tomography (CT) is the procedure of choice for initial evaluation of patients suspected of having chiasmal or perichiasmal lesions. Over 1000 patients were examined with high resolution CT, using axial and coronal scans, contrast enhancement, multiplanar reformations, and, when indicated, metrizamide CT cisternography. The normal anatomic appearance of the chiasm and neighboring structures are: (1) symmetric or asymmetric enlargement of the chiasm; (2) areas of abnormal density, without or with contrast enhancement, in the chiasm or perichiasmal region; (3) alteration of the suprasellar cistern; and (4) distortion of the anterior-inferior third ventricle.
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003390:Cranial Nerve Neoplasms / Q000000981:diagnostic imaging*; D003397:Craniopharyngioma / Q000000981:diagnostic imaging; D003560:Cysts / Q000000981:diagnostic imaging; D004407:Dysgerminoma / Q000000981:diagnostic imaging; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging*; D006099:Granuloma / Q000000981:diagnostic imaging; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009897:Optic Chiasm / Q000000981:diagnostic imaging*; D010911:Pituitary Neoplasms / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*