Computed tomography of benign disease of the paranasal sinuses

Abstract

Benign diseases affecting the paranasal sinuses may arise within the sinuses or may arise in adjacent tissues and involve the sinuses secondarily. With the exception of traumatic lesions, they are characterized radiologically by evidence of thickening of the mucosa, retention of secretions or the presence of a discrete soft tissue mass within one or more of the sinuses or the nasal cavity. They are distinguished from malignant lesions, in general, by their tendency to displace and deform bony walls and septa rather than to destroy them. Computed tomography in transaxial and coronal planes appears superior to other imaging modalities both for demonstrating the detailed structure of a lesion and for defining its extent. Level and window settings for both bone and soft tissue should be employed. A wide variety of benign lesions that affect the paranasal sinuses including congenital abnormalities, benign tumors, inflammatory and allergic conditions, complications of infection and obstruction, and traumatic lesions have been described and illustrated here.