Pulsatile Tinnitus: Differential Diagnosis and Radiological Work-Up

Abstract

Purpose of review: Identification of the underlying cause of pulsatile tinnitus is important for treatment decision making and for prognosis estimation. For this, an adequate diagnostic imaging strategy is crucial.

Recent findings: Both CT and MRI can be useful, and in general, these modalities provide complementary diagnostic information. The scanning protocol can be optimized based on the estimated a priori chance for finding specific pathology, or the need to rule out more rare but clinical significant disease. In recent years, dynamic CTA, also referred to as 4D-CTA, has become available as a new technique that enables non-invasive evaluation of hemodynamics for the detection, classification, and follow-up of vascular malformations.

Summary: The value of different diagnostic imaging modalities in the work-up of pulsatile tinnitus is discussed in relation to the differential diagnosis. Furthermore, imaging findings of different diseases are presented, both for CT and MRI.

Keywords: Angiography; MRI; Multi-detector CT; Pulsatile Tinnitus.

Fig. 1

T2-W (left) and phase-contrast MRA (right) demonstrating intracranial arteriovenous malformation (AVM) located in the right temporal fossa

Fig. 2

Dural arteriovenous fistula (dAVF) located in the right sigmoid sinus as identified by 4D-CTA and DSA. Left 4D-CTA lateral subtracted MIP demonstrating abnormal early contrast filling of the sigmoid sinus (white arrow) consistent with dAVF. Hypertrophic occipital artery identified as arterial feeder (black arrow). Anterograde venous drainage in the jugular vein. Middle Color-coded processing of 4D-CTA. Early contrast enhancement (arterial flow) is coded as red-orange, delayed contrast enhancement is coded as yellow-green. Notice the red-colored, hypertrophic occipital artery on the right side serving as arterial feeders of the dAVF. Right DSA, selective contrast injection of the external carotid artery showing a hypertrophic tortuous occipital artery (black arrows). Venous drainage of the sigmoid sinus into the jugular vein (white arrows) (Color figure online)

Fig. 3

Aberrant course of the internal carotid artery (arrow) and persistence of the stapedial artery (arrowhead) on thin-sliced CT. Note the absence of the foramen spinosum (encircled)

Fig. 4

Glomus tympanicum. Left Axial CT shows a soft tissue mass in the middle ear (arrows). No visible bony erosion. Right Axial contrast-enhanced T1-W with fat suppression demonstrates strong enhancement of this lesion (arrowhead)

Fig. 5

Glomus jugulotympanicum on CT and MRI. Left CT demonstrating erosive changes at the jugular bulb (arrows). Notice extension of the soft tissue into the middle ear (arrowhead). Middle Axial T1-W image shows a mixture of signal intensities due to vascular flow voids, which makes up the ‘salt and pepper’ appearance. Right Axial contrast-enhanced T1-W with fat suppression demonstrates avid contrast enhancement of the tumor

Fig. 6

Fenestral (left) and cochlear otosclerosis (right) on axial thin-sliced CT. Lucency of the fissula antefenestram (arrowhead) in fenestral otosclerosis. Lucent halo surrounding the cochlea (arrows) in cochlear otosclerosis

Fig. 7

Meningeoma on MRI. Axial contrast-enhanced T1-W images. Enhancing mass located in the left cerebellar-pontine angle with extension into hypoglossal canal (arrow), jugular plate (encircled), and the middle ear (arrowhead)