Axial unenhanced CT images through the sphenoid sinus. (A) Curvilinear calcifications (yellow open arrow) are seen in the sphenoid sinus when viewed utilizing bone algorithm. (B) Magnified views demonstrate additional curvilinear calcifications (blue open arrows). (C) When viewed utilizing lung algorithm, there are multiple small foci of fat identified (yellow open arrows). (D) Magnified views more clearly demonstrate these foci (blue open arrows).