Incidental findings involving the paranasal sinuses are common on CT and MR head scans performed in the acute setting. In the majority of cases, opacification of sinuses is secondary to mild inflammation and can be safely dismissed. However, recognising patterns and imaging features of paranasal sinus findings on these scans can opportunistically pick up pathology benefiting from further investigation or even identify the cause of presenting symptoms. After reviewing this exhibit, the reader will be able to: 1) Revise the basic anatomy and drainage pathways of the paranasal sinuses in order to understand patterns of disease; 2) review common and rarer benign and invasive paranasal sinus pathology using case examples; 3) recognise worrisome features that necessitate further investigation and referral.

1. Anatomy and imaging of the paranasal sinuses 2. Drainage pathways and patterns of disease 3. Interpretation and significance of pathological changes within paranasal sinuses a. Mucosal thickening b. Soft tissue density and bone changes c. Specific signs of acute/chronic/fungal disease 4. Signs of invasive and infiltrative disease a. Review areas 5. Complications of sinusitis