Radiological anatomy of the anterior ethmoidal artery for functional endoscopic sinus surgery.

Aim: This study investigated the extent to which the anterior ethmoidal artery and anterior ethmoidal foramen could be reliably identified on routine coronal sinus computed tomography scans. Where they could be identified, the relationship of these structures with the vertical height of the skull base, and their distance from an anterior landmark, were measured.

Methods: Fifty consecutive coronal sinus computed tomography scans were viewed independently by two observers. Scans were reviewed when the observers' opinions differed.

Results: Inter-observer concordance was high. The anterior ethmoidal foramen was visualised in 95 per cent of cases bilaterally and in the remaining 5 per cent unilaterally. The anterior ethmoidal artery was visualised in 33 per cent of scans. The anterior ethmoidal foramen was at skull base level in 72 per cent of sides studied, and below it in the remainder. The distance from the lacrimal crest to the anterior ethmoidal foramen was 22.4 mm (mean; standard deviation 3.7).

Conclusion: The anterior ethmoidal foramen is a reliable landmark on coronal computed tomography scans of the paranasal sinuses. From this, the position of the anterior ethmoidal artery can be inferred.