Densitometric analysis of the paranasal sinuses.

The knowledge of weak points in the osseous structure of the skull is of great importance for endonasal operations. For this reason the anatomy of the skull is accurately described in serial sections. Serial sections of 1.5 mm thickness are evaluated by a computerized image analyzing system, which allows qualitative as well as quantitative statements on the structure of the paranasal sinuses and their neighbourhood. The bone density in the frontobasal area of the skull as well as of the ethmoid cells is presented separately. The anatomy of the sphenoid sinus is described by densitometric and gross techniques.