Fig. 2. A. A schematic diagram shows the normal pneumatization of the sphenoid sinus and the surrounding anatomic structures in this area. B. A schematic diagram shows arrested pneumatization of the left sphenoid sinus. The lesion has multiple foci of fat, narrow sclerotic margins, and internal curvilinear calcifications. The left vidian canal passes through the region of arrested pneumatization. Note the well-preserved bony cortex of the canal.
