Reliability of preoperative multidetector computed tomography scan in patients with chronic otitis media

The objectives of this study were to specify the objective criteria of existence of cholesteatoma in chronic otitis media on the preoperative multidetector computed tomography (MDCT) and to evaluate the complications of disease.

We compared the results of preoperative MDCT scan with intraoperative findings in 71 patients (22 women, 49 men; mean age, 16-73 years) who had mastoidectomy operation between January 2008 and May 2012. Multidetector computed tomography evaluations of temporal bone were performed on a workstation using high-spatial-resolution magnified images with intended angle and plane.

We observed cholesteatoma formation in all patients with scutum erosion (n = 11), dural exposure (n = 6), and lateral semicircular canal fistula (n = 5). Computed tomography revealed these findings with 100% sensitivity. Distortion of ossicular integrity (n = 11) and facial canal dehiscence (n = 5) was significantly higher in cholesteatoma patients. Using the criteria of osteolysis, the sensitivity, specificity, and the accuracy rates of MDCT in detecting cholesteatoma were 71%, 93%, and 88%, respectively. The best diagnostic clue of a cholesteatoma was a mass-like soft tissue located in a retraction pocket in the posterosuperior quadrant of the Shrapnell membrane, causing widening of Prussak space and scutum erosion. Evaluation of computed tomography scan showed nearly 100% sensitivity in detecting tympanic opacification, dural height, dehiscence of lateral semicircular canal, tegmen tympani erosion, and deformation of malleoincudal articulation. However, its contribution to detecting minor ossicular erosion, facial canal dehiscence, and incudostapedial joint evaluation was limited.

Preoperative assessment of chronic otitis media via MDCT with intended angle and plane produces important guidance to understand the extent of disease and to prevent possible intraoperative complications.