Purpose: To study CT findings in general practice patients with a clinical diagnosis of acute sinusitis, and to examine the interobserver variation between 2 radiologists with regard to their CT evaluation.
Material and methods: Two hundred and one patients were examined with coronal CT images of the paranasal sinuses within 2 days of the clinical diagnosis. Patients with chronic sinusitis were excluded. Fluid level or total opacification of any sinus were used as evidence of sinusitis.
Results: One hundred and twenty-seven (63%) patients had fluid level or total opacification in a sinus region, most in more than one region. One hundred and fifteen had CT signs of sinusitis in the ethmoid region, 84 in the maxillary, 18 in the frontal, and 10 in the sphenoid. Forty-nine patients had a negative Ct. In the evaluation of interobserver agreement, the overall assessment of the CT yielded a kappa value of 0.70.
Conclusion: The study demonstrated great variation in the CT findings in general practice patients with suspected acute sinusitis. More than one sinus region was affected in most patients in whom sinusitis was confirmed by CT imaging; the most common combination was ethmoid and maxillary sinuses. The interobserver agreement was substantial.