Inflammatory diseases of the temporal bone: evaluation with CT and MR

Contrast enhanced CT and MR are complementary studies in evaluating inflammatory disease of the temporal bone. CT should be performed in preference to MR as the initial examination because of its ability to detect and delineate both soft tissue and bony abnormalities. CT should always be performed if intratympanic pathology is suspected, even if the MR examination is normal. MR can be used to distinguish effusion and cholesterol granuloma from other soft tissue masses in the tympanic cavity. Noncontrast MR cannot differentiate between cholesteatoma and granulation tissue. The efficacy of gadolinium-DTPA in inflammatory disease of the temporal bone awaits further investigation.