Aspergillosis is another mycotic infection that may produce clinical and radiographic findings similar to those of mucormycosis. The Aspergillus organism is a ubiquitous mold in agricultural dusts; in the immunosuppressed patient it can become a vicious pathogen. Characteristically, this infection involves several sinuses but is often unilateral. The pattern is unusual in that normal aerated cells may be seen among completely opacified cells. Smooth thickening of the sinus mucous membranes without associated air-fluid levels is another feature of aspergillosis. Cerebral involvement is more often due to hematogenous spread, primarily from the lungs, than to direct extension from the nose and sinuses. The CT and MRI appearance is similar to mucormycosis