Computed tomography (CT) accurately delineates the sphenoid sinus and its relationship to the rest of the cranial base, cranial tbssae, nasopharynx and orbits. Thus, the extent of a sphenoid sinus lesion can be clearly demonstrated. Superoinferior delineation is obtained by analyzing multiple adjacent sections. CT characterizes the lesions as to density, homogeniety and association of bony changes. This aids in the differential diagnosis.