When is Magnetic Resonance Imaging most beneficial in olfactory
dysfunction? A retrospective review of a tertiary referral smell and
taste clinic
Abstract
Background Olfactory dysfunction (OD) is a common but underreported
problem that can significantly impact a patient’s quality of life.
Dysfunction is prevalent in over 5% of the adult population and can be
broadly categorised into conductive and sensorineural causes. Magnetic
Resonance Imaging (MRI) can form part of the diagnostic work up,
although its exact role is often debated. Objectives The aim of this
study was to evaluate the value of MRI in managing patients with OD.
Design/ Method A retrospective analysis of the records of patients
presenting to national smell and taste clinic over a five-year period
was performed. Variables included demographics, endoscopic findings,
final diagnosis, psychophysical smell test and MRI results. Results A
total of 409 patients underwent clinical assessment and smell testing
for OD, of which 172 patients (42%) had MRI scans performed. The age
range of patients was 10 to 93 years. Imaging in younger age-groups was
associated with a higher rate of positive findings, however identifiable
causes for OD were recorded across the range. MRI provided both
diagnostic and prognostic information in those with idiopathic,
traumatic, and congenital causes of OD. For example, MRI provided
information on the extent or absence of traumatic gliosis in those with
a head trauma history allowing further treatment and prognosis.
Conclusion We recommend the adjunct use of MRI in patients with a clear
history and examination findings of head injury, congenital cases and in
apparent idiopathic cases. MRI should be requested to compliment
clinical findings with a view to aiding decision-making on treatment and
prognosis independent of patient’s age.