Diagnostic yield of MRI of the brain and IAC in patients with neurotologic complaints

Abstract

Objectives: Quantify number of MRI scans obtained in a tertiary neurotology practice and identify likelihood of pathologic findings.

Study design: Retrospective cohort study.

Setting: Tertiary neurotology center.

Subjects and methods: A retrospective analysis of all adult patients over 20 months (3/2012-10/2013) where MRI was deemed necessary for evaluation of neurotologic complaints. Demographics, clinical history, physical examination, and audiometric findings were used to categorize new patients into 7 groups: definite Meniere's disease (MD), probable MD, possible MD, vague dizziness, tinnitus only, asymmetric hearing loss (HL), and other symptoms to stratify risk for retrocochlear tumor and other relevant pathology.

Results: 1537 MRI scans were performed, 932 of these were for a new diagnosis. Discovering retrocochlear tumors was rare (1.4%). Patients with HL had a 0.3% (1/314) chance of retrocochlear tumor and 3.2% (10/314) chance of relevant pathology. Patients with only unilateral tinnitus had no evidence of retrocochlear tumors, and 3.8% chance of finding relevant pathology. Patients with "definite" or "probable" MD had no evidence of retrocochlear tumor or other relevant findings. All discovered acoustic neuromas were in the "possible MD" category, which had a 9.3% chance of finding all relevant pathology.

Conclusions: In a tertiary neurotology center, the likelihood of finding a retrocochlear tumor on MRI is rare. In the current study, unilateral tinnitus exclusively, "definite MD," and "probable MD" failed to yield a single example of retrocochlear tumor. Patients with "possible MD" had the highest probability of finding retrocochlear tumors and other relevant pathology.

Keywords: Acoustic neuroma; Dizziness; Hearing loss; MRI scan; Retrocochlear pathology; Tinnitus.