Detecting causes of pulsatile tinnitus on CT arteriography-venography: A pictorial review

Abstract

Pulsatile tinnitus (PT) can be a mild or debilitating symptom. Following clinical examination and otoscopy, when the underlying aetiology is not apparent, radiological imaging can be used to evaluate further. CT arteriographyvenography (CT A-V) of the head and neck has recently been introduced as a single 'one catch' modality for identifying the many causes of PT including those which are treatable and potentially serious whilst also providing reassurance through negative studies or studies with benign findings.CT A-V is performed as a single phase study allowing both arterial and venous assessment, hence limiting radiation exposure. Additional multiplanar reformats and bone reconstructions are desirable. Understanding the limitations of CT A-V is also required, with an awareness of the scenarios where other imaging modalities should be considered.The causes of PT can be divided into systemic and non-systemic categories. Non-systemic aetiologies in the head and neck should be carefully reviewed on CT A-V and include a variety of vascular causes (arteriovenous malformations/fistulas, venous or arterial aetiologies) and non-vascular causes (tumours and bony dysplasias). Venous causes (dominant, aberrant, stenosed or thrombosed venous vessels) are more common than arterial aetiologies (aberrant or stenosed internal carotid artery, aneurysms or a persistent stapedial artery). Glomus tumours that are not visible on otoscopy and osseous pathologies such as bony dehiscence and otospongiosis should also be excluded.Careful assessment of all the potential vascular and non-vascular causes should be reviewed in a systematic approach, with correlation made with the clinical history. A structured reporting template for the reporting radiologist is provided in this review to ensure all the potential causes of PT are considered on a CT A-V study. This will help in providing a comprehensive radiological evaluation, hence justifying the radiation dose and for patient assessment and prognostication.

Pediatric tinnitus: The role of neuroimaging

“…An aberrant ICA (Figure 1) corresponds to an arterial collateral that develops secondary to the involution of the cervical ICA and runs through a prominent inferior tympanic canaliculus within the middle ear cavity and lateral to the cochlear promontory to eventually join the petrous ICA within the carotid canal through a dehiscent carotid plate 2,3 . On otoscope, the aberrant ICA can mimic a retrotympanic soft tissue mass such as glomus tumor 8 .…”

“…On otoscope, the aberrant ICA can mimic a retrotympanic soft tissue mass such as glomus tumor 8 . This can be associated with persistent stapedial artery in 30% of cases 2,3 …”

“…Tinnitus may be classified as pulsatile versus continuous (ie, nonpulsatile). Pulsatile‐type tinnitus is a repetitive auditory perception in synchrony with the patient's pulse, unlike the continuous‐type that lacks the rhythmic quality 2,3 …”

“…Pulsatile-type tinnitus is a repetitive auditory perception in synchrony with the patient's pulse, unlike the continuous-type that lacks the rhythmic quality. 2,3 The reported prevalence of pediatric tinnitus in the literature varies widely and has been reported to range from as low as 5% to as high as 90%. 4,5 It is considered more prevalent when concurrent hearing loss is present with a higher incidence in children with conductive hearing loss from otitis media compared to children with sensorineural hearing loss.…”

“…Most patients with isolated continuous tinnitus do not require imaging as previous studies have shown that rarely abnormal Cephalocele of the temporal bone imaging findings are encountered unless there are additional associated symptoms such as sensorineural hearing loss in which case MRI is the modality of choice. 3 High incidences of inner ear anomalies (eg, semicircular canal dysmorphism, enlarged vestibular aqueduct, and cochlear hypoplasia) were reported in pediatric tinnitus, especially in the presence of hearing loss. 7 CT is especially useful in diagnosing any trauma-related changes of the temporal bone that may explain continuous tinnitus.…”