Variation among pre-surgical CT assessments of chronic otitis media

To investigate the reliability of preoperative computed tomography (CT) in patients with chronic otitis media (COM) as assessed by otologist-ENT surgeons, compared with surgical findings and respective radiological assessments, and to identify areas of the middle ear that are difficult to evaluate reliably with preoperative CT.

Fifty patients with COM underwent preoperative temporal bone CT reported by a qualified radiologist. Each operating surgeon completed a standardized questionnaire regarding the status of 10 middle-ear structures after the operation. Two otologists blindly reviewed the scans. AC1-statistics between the radiology/otology report and the intra-operative findings were calculated.

In the attic, malleus-incus complex, tympanic cavity, and round window niche, the otologists' assessments of CT scans corresponded better to intra-operative findings than did the respective radiology report. In the lateral semicircular canal and sigmoid sinus, the otologists' assessments also outperformed those of the radiologists in cases of erosion. Radiological assessments outperformed those of otologists in only one of 10 studied areas: confirmation of an unexposed dura in the tegmen area. The scutum and oval window represent difficult areas for which to obtain a reliable preoperative CT scan report.

Otologists' assessments regarding the pre-surgical status of the temporal bone in COM appear more reliable than those of radiologists. This finding has serious implications in current clinical practice, and should be considered when designing strategies for Radiology Head & Neck training. The inherent limitations of CT may necessitate modifications to imaging and operating strategies.