Imaging of tinnitus: A review

Tinnitus, a buzzing or ringing in the ear, may be pulsatile or continuous ( nonpulsatile). The distinction, with a detailed clinical evaluation, determ ines the most appropriate imaging study. Pulsatile tinnitus suggests a vasc ular neoplasm, vascular anomaly, of-vascular malformation. Most of the neop lasms are glomus tympanicum and glomus jugulare tumors. Vascular anomalies may cause pulsatile tinnitus,but the mechanism is unknown,and another (trea table) cause should be sought. Most neoplasms and anomalies are best seen o n bone algorithm computed tomographic (CT) studies. Dural vascular malforma tions are often elusive on all cross-sectional! imaging studies; convention al angiography may be necessary to make this diagnosis, Flow-sensitive magn etic resonance (MR) images show vascular loops compressing the eighth crani al nerve. Carotid dissections, aneurysms, atherosclerosis, and fibromuscula r dysplasia can be identified on both MR imaging or MR angiographic studies and CT or CT angiographic studies. Otosclerosis and Paget disease are CI d iagnoses. Benign intracranial hypertension often has no abnormal imaging fi ndings. For patients with nonpulsatile tinnitus, MR imaging is the study of choice to exclude a vestibular schwannoma or other neoplasm of the cerebel lopontine angle cistern. Multiple sclerosis and a Chiari I malformation are rare causes of pulsatile tinnitus, also best seen on MR studies. Many pati ents with tinnitus have no abnormal imaging findings.