Fig. 1
From: Risky anatomical variations of sphenoid sinus and surrounding structures in endoscopic sinus surgery
Güldner’s classification7 of sphenoid sinus pneumatization on sagittal CT images: A conchal, B presellar, C sellar, and D postsellar pneumatization types. Axial CT images showing (E) right dehiscent internal carotid artery (ICA) and protrusion of accessory sphenoid septa into the left ICA, F deviation of the sphenoid septum in left ICA protrusion, G accessory septations with attachment on the right ICA; G endoscopic right sphenoid sinus show an accessory septations (*). Coronal (H) CT image revealing bilateral pterygoid recess pneumatization. Coronal (L) and sagittal (M) CT scans showing dehiscence of the left optic nerve (ON) and attachment onto the sphenoid sinus (white arrow)