Complementary use of computed tomography and magnetic resonance imaging in assessing skull base lesions.

Twenty-six patients underwent computed tomography (CT) and magnetic resonance imaging (MRI) of skull base lesions at the Cleveland Clinic Foundation. CT provided improved bone detail, documenting invasion of the lamina papyracea, orbital floor, fovea ethmoidalis, cribriform plate, pterygoid plates, hard palate, and skull base. MRI defined invasion of the orbit, dura, brain, and cavernous sinus. Improved soft-tissue-tumor interface was evident on MRI. MRI was superior to CT in determining carotid artery involvement. MRI distinguished between tumor and retained secretions in the paranasal sinuses. Combining radiographic tumor staging reliably predicted surgical findings; however, MRI consistently yielded sufficient diagnostic information and the additional expense of performing two imaging procedures may not be justified.