A pain in the ear: the radiology of otalgia.

Otalgia is ear pain. Ear disease causes primary otalgia. Secondary (referred) otalgia is referred to the ear from disease in structures remote from the ear. Otalgia, especially referred otalgia, can be a diagnostic challenge. The radiologic approach to a patient with otalgia relies on the physical examination. If the otoscopic findings are abnormal, the computed tomographic (CT) or magnetic resonance (MR) study focuses on the temporal bone. (The appropriate radiologic study depends on the disease.) The physical examination for ear pain includes the ear (auricle and temporal bone) and structures that are potential sources of referred pain. Imaging studies can show clinically occult temporal bone disease as well as sources of referred pain in the nasopharynx, retropharynx, paranasal sinuses and nasal cavity, temporomandibular joint (TMJ), parotid gland, oropharynx and oral cavity (including teeth), hypopharynx and larynx, thyroid gland, esophagus, and trachea. Tailoring a CT or MR study to evaluate primary or referred otalgia requires an understanding of the (admittedly complex) anatomy of ear pain.