Figure 1:

The volumetric analysis of the lateral recess of the sphenoid sinus (a and b) and representative cases (c-e) using coronal computed tomography. The upper yellow arrow shows the foramen of rotundum, and the lower arrow shows the Vidian canal (a). A line was drawn through the two points and the area in the sphenoid sinus lateral side of the line on each slice was measured (b). Well-pneumatized case (c), moderately pneumatized case (d), and poorly pneumatized case (e).