A systematic approach to the interpretation of computed tomography scans prior to endoscopic sinus surgery.

Computed tomography (CT) provides an excellent map for the sinus surgeon as well as providing information about the extent of disease and the presence of bony destruction. Surgeons need to be aware of the anatomical configuration of the sinuses and the presence of any structural changes such as a dehiscent lamina papyracea, asymmetric skull base, low level of posterior skull base or an Onodi cell, which place the patient at increased risk. Described here is a six-step guide to help the sinus surgeon avoid missing any of the radiologically important features.