Neighbouring relations of the posterior ethmoid studied by axial computed tomography.

The anatomy of the paranasal sinuses is variable and it is important to appreciate their clinical and surgical significance. During both posterior ethmoid and sphenoid sinus surgery, but also for endoscopic approach of pituitary, a good knowledge of the anatomy is essential for understanding the pathological process and to prevent surgical complications (optic nerve, internal carotid artery injury during surgery). Although coronal Computerized Tomography (CT) is the routine procedure performed for functional endoscopic sinus surgery (FESS), axial CT is most useful in demonstrating the anatomy of the posterior ethmoid and the sphenoid sinus. The authors comment the posterior ethmoid cells and its variable relationship with the sphenoid sinus and its intimate association with the optic nerve, for using a pictorial axial CT by studying 50 CT head region.