Can Hounsfield Unit Density Accurately Predict Recurrent Cholestatoma in Previously Operated Ears?

The objective of the study was to determine whether Hounsfield Unit density would differentiate between cholesteatoma and other causes of opacification, such as granulation tissue in previously operated ears. Temporal bone computer tomography (CT) scans of 47 patients, who had revision mastoid surgeries, were evaluated retrospectively. A circular 5 mm2 region of interest (ROI) was placed at aditus ad antrum to measure Hounsfield Unit (HU) density. There was no statistically significant difference between cholesteatoma and non-cholesteatoma groups in terms of HU densities. Intraclass correlation coefficient test showed an intraclass correlation of 0.41 between measurements done by radiologists and otorhinolaryngologists, which showed poor reliability. Contrary to previous studies in unoperated ears, in operated ears HU density at aditus level cannot be a reliable diagnostic adjunct. Moreover, when it is considered that interrater reliability was poor between radiologists' and otolaryngologists' measurements, a need for further studies arise to solidify findings in this study. Key Words: Cholesteatoma diagnostic imaging, Middle ear surgery, Revision mastoidectomy.