Purpose: To evaluate the interobserver agreement in the CT assessment of the anterior ethmoidal artery canal (AEC) dehiscence Methods: A retrospective review of consecutive 1008 CT scans of the paranasal sinuses (PNS) between January 1, 2012 and December 31, 2012 was performed. Cases with the AEC in the ethmoidal roof/skull base, postoperative changes  or pathology causing alteration of the anatomy were excluded. Two neuroradiologists, read all the cases. Each neuroradiologist assessed the presence of AEC dehiscence, the presence of paranasal opacification and the best plane to evaluate the AEC. The interobserver agreement was calculated for all the cases. Results:  A total of 301 AEC was included. 102 cases demonstrated the AEC below the skull base bilaterally (51,2%), 44 cases were only in the right side (22,1%) and 53 cases only on the left side (26,6%). The best plane to assess the anterior ethmoidal canal for reader 1 was the coronal (53%), for reader 2 the best plane was the sagittal (77.7%). Dehiscence of the AEC was found in 41 cases (20%) for reader 1, for reader 2 was found in 22 cases (11%). The Kappa for dehiscence of the AEC was 0,246 indicating fair interobserver agreement.  Opacification of the paranasal sinuses was found in 59 cases (19%) for reader 1 and in 77 cases (25%) for reader 2. The kappa for the dehiscence of the AEC in cases with opacification of the paranasal sinuses was 0,754, indicating good interobserver agreement. Conclusion: Suboptimal interobserver agreement can potentially limit the usefulness of CT scan to preoperatively assess the AEC dehiscence.

Ct Assessment Of Anterior Ethmoidal Canal Dehiscence; an interobserver agreement study