Clinical Research Directory

Inclusion Criteria: * Age 18 years or above * Olfactory dysfunction (i.e., a TDI score \< 30.75) * Eligible for treatment with biologics (i.e., meeting the Danish criteria for treatment with biologics (40) which includes fulfillment of the EPOS criteria for CRS. * Either treatment naïve to biologics or had their first injection within a maximum of 48 hours prior to the scan. * No other obvious explanation for the olfactory dysfunction (including, but not limited to: head trauma, sinus surgery, tumors in the nose or brain, upper respiratory infection, neurological or psychiatric disease) * Control group: normosmic at baseline (i.e., TDI-score \>30.75) Exclusion Criteria: * Previously recognized loss of sense of smell and taste due to other sinonasal or neurological conditions. * Neurodegenerative disorders known to cause olfactory deficits (Parkinson's, Alzheimer's, Lewy-Body Dementia, Amyotrophic lateral Sclerosis etc.) * Other obvious explanation for the OD (i.e., smell loss occurring in relation to one of the following (including, but not limited to): head trauma, sinus surgery, upper respiratory infection. * Contraindications for MRI scan including: * Implants or prostheses of magnetic metal * Metal foreign bodies * Pregnancy * Severe claustrophobia * Unable to complete the full MRI session. * Not able to comprehend written and/or spoken Danish language.