What Is the Best Imaging Modality in Evaluating Patients with Unilateral Pulsatile Tinnitus?

by Syed F. Ahsan, MD, Michael Seidman, MD, and Kathleen Yaremchuk, MD •

Trio Best PracticeTRIO Best Practice articles are brief, structured reviews designed to provide the busy clinician with a handy outline and reference for day-to-day clinical decision making. The ENTtoday summaries below include the Background and Best Practice sections of the original article. View the complete Laryngoscope articles free of charge.

Background

Pulsatile tinnitus (PT) is a relatively rare cause of tinnitus. It makes up about 4% of patients with tinnitus, which in turn affects up to 10% of the population. PT can be described as objective or subjective, as well as venous, arterial, or nonvascular. About 20% of PT patients will have objective tinnitus. Incidence of abnormal, often treatable, structural findings in patients with PT has been noted to be high, ranging from 44% to 91%. PT can be a result of vascular as well as neoplastic causes, and if left undiagnosed, it can lead to significant morbidity and mortality. Overlooking an aneurysm or a tumor may be catastrophic for the patient; therefore, further investigation is highly recommended. In this Best Practice review, we aim to evaluate the various imaging modalities and determine which may be the best initial test in patients presenting with unilateral PT.

Best Practice

Deciding on the initial radiographic evaluation in patients with unilateral PT can be challenging due to the many causes as well as the questionable results of some of the imaging findings. Recent studies have shown an increase in the cases of SSDD, which is best visualized on a CT scan. In addition, sensitivity and specificity analysis have shown that CTA may be the best initial test in patients with unilateral subjective PT. For patients with objective PT with no middle ear mass, a CTA is the best initial exam. For those others with subjective unilateral PT, it is important to distinguish between venous and arterial PT. For patients with signs and symptoms of IIH, MRI/MRV is the appropriate initial study. And for the remaining cases of venous and arterial PT, consider CTA as the best initial study due to safety and broad effectiveness (Laryngoscope. 2015;125:284-285).