Major patterns of inflammatory sinonasal diseases on CT

ABSTRACT

Paranasal sinus CT is known as the most effective imaging modality in the evaluation of inflammatory sinonasal diseases and can depict the distribution, causative lesions obstructing main drainge route, and associated findings. Recently, functional endoscopic sinus surgery has been widely used for the evaluation and treatment. Before operation, PNS CT has been routinely used to evaluate the paranasal sinuses and mucociliary drainage route. The authors analyzed the PNS CT findings of 3156 cases in 1578 patients with chronic sinusitis symptoms. Sinonasal inflammatory diseases were categorized into 5 patterns according to the obstruction sites. They were 1) infundibular (10%, 316/3156), 2) ostimeatal unit (41%, 1294/3156), 3) sphenoethmoidal recess (12%, 379/3156), 4) sinonasal polyposis (30%, 946/3156) , and 5) unclassifiable (6%, 190/3156) patterns. The main causes for infundibular obstruction in order of frequency were inflammatory mucosa, enlarged ethmoidal bulla and Haller's cell. With respect to the middle meatus obstruction, is main causes in the order of frequency were polypoid lesion, inflammatory mucosa and medially deviated uncinate process. In particular, sinonasal polyposis showed one or more of the characteristic associated findings of infundibular enlargement, air-fluid level, ethmoidal sinus was bulging and bony deossification or sclerosis as well as sinonasal polypoid change. In conclusion, the inflammatory sinonasal diseases were classified into five patterns, and the causative lesions or anatomic variations were efficiently detected by the PNS CT. Furthermore, it could provide a guidance for proper management of the sinusitis including functional endoscopic sinus surgery.