title: High resolution CT air cisternography in the diagnosis of small acoustic neuromas.
abstract: High resolution CT air cisternography was used to examine 38 patients with clinical findings and audiovestibular function studies consistent with a retrocochlear lesion. Four strictly intracanalicular lesions and 10 acoustic neuromas extending medially into the cerebellopontine angle (CPA) cistern by no more than 1 cm were detected and verified at surgery. There was one false-positive diagnosis produced by a tortuous inferior cerebellar artery branch. The contrast-enhanced axial scan was positive in only two patients. Both had extension of the tumor into the CPA by 1 cm. In these two cases the axial intravenous (IV) contrast-enhanced scan provided more information than the air CT. A patient with suspected acoustic neuroma is best examined initially with an IV contrast-enhanced axial scan followed by CT air cisternography where the contrast study is negative.
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
chemical_list: D003287:Contrast Media