[X-ray computed tomographic study of the ethmoid and middle meatus. I. radioanatomy (coronal plane)].

The advance of endoscopic endonasal surgery allows limited surgical resection in chronic rhinosinusitis. An accurate topographic evaluation of diseases and individual morphologic variation are necessary for this functional surgery. The preoperative radiological investigations require a precise knowledge of ethmoid and osteo-meatal unit anatomy. Thin sections by high resolution CT were performed in coronal plane. The anatomical land marks and the ethmoidal bony roots, which allow a study of the osteo-meatal unit and ethmoid air cells system, are showed. Like endoscopic view, coronal slices better display the different grooves for paranasal sinus draining and their relations with the ethmoid.