Usefulness of computed tomography Hounsfield unit density in preoperative detection of cholesteatoma in mastoid ad antrum.

PURPOSE: This study was performed to evaluate the usefulness of Hounsfield unit (HU) to better distinguish cholesteatoma from other inflammatory conditions in the mastoid ad antrum before primary mastoid surgery.

MATERIALS AND METHODS: We enrolled 82 patients who underwent tympanomastoidectomy for treatment of chronic otitis. Forty-one patients were pathologically diagnosed with cholesteatoma, whereas the others were diagnosed with inflammatory granulation. These lesions were confirmed, and HU was measured in preoperative computed tomography. The difference in HU between cholesteatoma and non-cholesteatoma tissues was analyzed, and the improvement in the diagnosis of cholesteatoma after inclusion of HU data was calculated.

RESULTS: The HU was calculated as 42.68 ± 24.42 in the cholesteatoma group and 86.07 ± 26.50 in the non-cholesteatoma group. The differences between the 2 groups were statistically different (Student t test, P < .01). By applying the HU, the sensitivity (51.2%-80.5%), specificity (80.5%-87.8%), positive predictive value (72.4%-86.8%), and negative predictive value (62.3%-81.8%) to diagnose cholesteatoma improved.

CONCLUSIONS: The HU density was found to be statistically different between cholesteatoma and inflammatory granulation tissue in mastoid antrum. An improved diagnosis of cholesteatoma was achieved after adjusting for the HU.