Figure 1: Sphenoidal sinus osteomyelitis.
A) Fat suppressed T2 image in the axial plane showing sphenoid sinusitis, altered signal intensity in adjacent bones with expansion of right cavernous sinus by soft tissue (white arrows). B) Subtracted post contrast T1 image in the axial plane showing enhancing soft tissue thickening in the right cavernous sinus with extension to the orbital apex. There is an enhancement of the adjacent right optic nerve and the right half of the optic chiasma shows abnormal signal intensity (white arrows). C) Post contrast T1 image in the coronal plane shows a striking asymmetry of the right cavernous sinus due to enhancing soft tissue within it. Note the narrowed caliber of the cavernous segment of the right internal carotid artery compared to the left (white arrow).