Petrous Apex Disease

The petrous apex, which is the most medial portion of the temporal bone, is also a complex region of the central skull base. Lesions arising in or spreading to the petrous apex can cause varied and severe sequelae, which may result from mass effect or direct invasion of the cranial nerves, brainstem, or internal carotid artery. Because the petrous apex is not amenable to direct examination, HRCT and MR imaging plays an important role in diagnosis and characterization of lesions occurring there, and in aiding surgical planning.