Differential diagnosis of primary petrous apex lesions.

Accurate preoperative diagnosis of petrous apex lesions is critical because the surgical approaches used for this region are different depending upon the specific disease process involved. While CT and MRI have each improved the accuracy of preoperative diagnosis of petrous apex pathology, these imaging studies are most helpful when used in conjunction with one another. When systematically applied, the combination of CT with contrast and MRI (with and without gadolinium) permits accurate differential diagnosis of primary petrous apex lesions. This review presents the imaging approach employed at the House Ear Clinic for the differential diagnosis of primary lesions of the petrous apex.