Radiologic imaging in the management of sinusitis.

Sinusitis is one of the most common diseases treated by primary care physicians. Uncomplicated sinusitis does not require radiologic imagery. However, when symptoms are recurrent or refractory despite adequate treatment, further diagnostic evaluations may be indicated. Plain radiography has a limited role in the management of sinusitis. Although air-fluid levels and complete opacification of a sinus are more specific for sinusitis, they are only seen in 60 percent of cases. Noncontrast coronal computed tomographic (CT) images can define the nasal anatomy much more precisely. Mucosal thickening, polyps, and other sinus abnormalities can be seen in 40 percent of symptomatic adults; however, clinical correlation is needed to avoid overdiagnosis of sinusitis because of nonspecific CT findings. Use of CT is typically reserved for difficult cases or to define anatomy prior to sinus surgery. Magnetic resonance imaging (MRI) cannot define bony anatomy as well as CT. MRI is only used to differentiate soft-tissue structures, such as in cases of suspected fungal infection or neoplasm. Referral will occasionally be needed in unusual or complicated cases. Immunocompromised persons and smokers are at increased risk for serious sinusitis complications.