[Imaging of conductive hearing loss].

CT study of the middle ear and ossicular chain plays a major role in assessing the etiology of conductive hearing loss. A normal otoscopic examination is compatible with a fenestral otosclerosis, a minor ossicular chain aplasia or a traumatic dislocation of the ossicular chain. Fenestral otosclerosis diagnosis does not usually require a CT examination except in children without familial history and mixed hearing loss with a transmissional component. In retraction pockets and middle ear cholesteatomas CT allows precise location, extension and defines surgical landmarks. In middle ear tumors CT and MR studies need to be used in conjunction to differentiate glomus tumor, primary cholesteatoma and congenital vascular anomalies.