Figure 6. (a) Axial CT scan demonstrates groundglass appearance in fibrous dysplasia of the anterior skull base. Post-gadolinium T₁ weighted spin echo coronal (b) and STIR sagittal (c) images demonstrate extensive frontoethmosphenoid fibrous dysplasia. The cortical bone in the anterior cranial base is elevated but intact. The high signal on STIR images represents cystic component and there is marked enhancement of the intervening septae compared with the pre-contrast image (not shown).