Cholesteatoma remains a clinical diagnosis but today imaging has become an important cornerstone in the diagnostic work-up of this condition. Conebeam CT offers a much higher resolution of the interface between bone, air and soft tissue, while the associated irradiation dose is substantially lower, as compared to multi-detector CT scans. As such, CBCT has become very useful for the pre-op work-up of patients with cholesteatoma showing with precision bony erosion of the ossicular chain and erosion of the petrous bone (as fistulae, perilabyrinthine erosion, intracranial invasion). Also the aeration of the ME-cleft is shown (important for the functional prognosis) and important preoperative landmarks warn the surgeon for eventual pitfalls.

The advent of the non-EP diffusion weighted sequence in MR-imaging makes this sequence a very useful adjunctive tool in the pre-op work-up of cholesteatoma cases specially in cases suspected of intralabyrinthine spread, or extension medial to the otic capsule or intracranial invasion. Its today almost undisputed value has been demonstrated in the postoperative follow-up of cholesteatoma by the high sensitivity and specificity (in most studies well above 90%). By this innovation many “unnecessary” (because absence of residual pathology) second stage operations can today be avoided. Advantages and limitations of the two imaging techniques will be discussed.

An algorithm usefull in clinical practice will be proposed