Paranasal sinus radiology, Part 3A: sphenoidal sinus.

This article describes the complex anatomy of the sphenoid bone. The development and size of the sphenoidal sinuses are quite variable and complete analysis of the sinus walls requires several views. The essential plain film projections and use of tomography and CT scans are described. Sphenoidal sinus inflammatory disease produces changes similar to those already discussed in the articles in this series on the frontal sinus and the ethmoidal sinus. Illustrations of sphenoidal sinus inflammatory disease are provided.