Magnetic resonance imaging and audiologic assessment of middle ear effusions in patients with nasopharyngeal carcinoma before radiation therapy

Objective: The aim of this study was to assess the performance of clinical methods, viz. otoscopy, pure-tone audiometry, and tympanometry in diagnosin g middle ear effusions (MEEs) using magnetic resonance imaging as a referen ce standard. Study Design: A retrospective study of 46 patients with newly diagnosed nas opharyngeal carcinoma was performed comparing clinical evaluation and audio metry results with magnetic resonance imaging findings obtained before radi ation therapy. Results: Twenty-two (25%) Of the temporal bones imaged had both MEE and mas toid effusions, 24 (27%) had only middle eat fluid, and 29 (33%) had mastoi d fluid alone. The sensitivity for tympanometry, audiometry, and otoscopy i n detecting fluid in the middle ear was 96%, 92%, and 80%, respectively. Al though tympanometry was most sensitive in diagnosing MEE, there was no stat istically significant difference when comparing the overall accuracy of pur e-tone audiometry air-bone gap and tympanometry (p = 0.7, chi-square test). Flat curve tympanograms (type B) only achieved a sensitivity of 45% but we re of high specificity (92%). Forty-nine percent with negative pressure tym panograms (mean air pressures > -100 daPa) had no MEE. Conclusions: Using magnetic resonance imaging as a reference standard, tymp anometry is the mast sensitive audiologic test in detecting the presence of MEE. The overall accuracy of tympanometry, pure-tone audiometry air-bone g ap, and otologic examination was, however, not significantly different.