[Contribution and role of the scanner in the preoperative evaluation of chronic otitis. Radiosurgical correlation apropos of 85 cases]. / Apport et place du scanner dans le bilan pré-opératoire de l'otite chronique. Corrélation radio-chirurgicale à propos de 85 cas.

ABSTRACT

High resolution computed tomography (CT) is today the best imaging to study chronic middle ear diseases. In a retrospective analysis of 85 chronic otitis media (cholesteatoma or not), the authors emphazise the diagnostic value of CT scan, its preoperative's role and the radiologic imaging of cholesteatoma. In our study, the radiosurgical correlation rate is 0.6 regarding positive diagnosis in chronic otitis or cholesteatoma. The malleus and incus analysis is correct, but stapes is not observed in 40% of cholesteatoma. The correlation of surgical and radiographic findings is excellent regarding the scutum, the horizontal semicircular canal (> 0.7), the tegmen (= 0.6), bad for the canal of facial nerve (< 0.5). The actual extent of chronic otitis media lesions is overestimated by CT scan in 70% of cases. The correlation's rate is reliable for epitympanum and aditus. To conclude, the preoperative CT is necessary in those cases closed eardrum cholesteatoma, single functional ear, clinical complications and doubtful diagnosis.