ESR Essentials: diagnostic strategies in tinnitus-practice recommendations by the European Society of Head and Neck Radiology.

Tinnitus is common, with approximately 1/4 of the elderly population experiencing chronic tinnitus. While non-pulsatile tinnitus usually has no structural cause, pulsatile tinnitus is more likely to have an identifiable aetiology, and imaging plays a key role in the search for treatable and life-threatening causes. Since the characteristics of the tinnitus guide the diagnostic strategy, a detailed clinical assessment should always be performed before imaging is considered. In the setting of non-pulsatile tinnitus, imaging with MRI should only be performed if it is unilateral or asymmetric, or when it is associated with focal neurologic abnormalities or asymmetric hearing loss. In contrast, imaging investigation is always required in the presence of pulsatile tinnitus. Whilst there are specific clinical features in which temporal bone CT will be the initial imaging strategy for pulsatile tinnitus (e.g., retrotympanic mass or conductive hearing loss), most patients will require either CT or MRI with arterial and venous imaging. The clinical categorisation of pulsatile tinnitus as "arterial" or "venous" may guide the radiological search and help understand the significance of certain imaging findings (e.g., venous variants). Significant pathology (e.g., dural arteriovenous malformation) must be excluded in the context of objective pulsatile tinnitus and may require additional cross-sectional imaging; conventional angiography is now rarely indicated. KEY POINTS: In patients with unilateral, non-pulsatile tinnitus, MRI should be performed to rule out retrocochlear disease. All patients with pulsatile tinnitus should be imaged and the clinical assessment guides the selection of the most appropriate imaging technique. If the first imaging study does not reveal the suspected cause of objective pulsatile tinnitus, additional imaging investigations should be performed to exclude alternative diagnoses.