Petrous apex and cavernous sinus: anatomy and pathology.

The cavernous sinus (CS) and petrous apex (PA) are contiguous. The cavernous space and cranial nerves III and VI are intimately associated with each. To accurately interpret computed tomography (CT) and magnetic resonance (MR) images of this region, one must understand thoroughly the anatomy of the PA and CS. This article begins with a detailed review of this anatomy, followed by a discussion of pathology. Intrinsic diseases of the CS and PA are emphasized specifically.