ABSTRACT
Historically, surgical procedures to alleviate recurrent or chronic sinusitis were directed at the larger paranasal sinuses. The radiological features of chronic sinusitis are similar to those of acute sinusitis when there is an acute process superimposed upon the chronic disease. Acute sinusitis is characterized clinically by malaise, nasal obstruction, purulent nasal discharge, postnasal drip, and facial pain. The classic magnetic resonance imaging (MRI) appearance of benign inflammatory sinusitis is thickened mucosa of low to intermediate signal intensity on T1-weighted scans. Mucous retention cysts seen in the floor of the maxillary sinus are most frequently the result of occlusion of the submucosal mucinous glands. Nasal polyps are demonstrated on computed tomography by the finding of unilateral or bilateral soft tissue masses within the nasal cavity and paranasal sinuses. The characteristic MRI feature of sinonasal polyposis is a reflection of the rich proteinaceous and watery contents of these polyps.
