Fig. 1From: An additional challenge for head and neck radiologists: anatomic variants posing a surgical risk – a pictorial reviewOnodi cell. Coronal (a) and axial (b) MDCT images show a large air-cell (asterisk) along the superolateral aspect of the right sphenoid sinus (ss), corresponding to an Onodi cell. Pneumatization extends to the anterior clinoid process; consequently, the optic nerve canal protrudes slightly within the Onodi cell (arrowhead)Back to article page