Recognize the position and course of AEA through focused reading of CT scan of the patients is very crucial before surgery, As Wong et al. described that the area of the AEA is fundamental and important for surgeon due to their worries regarding the possible complications (such as bleeding, CSF leak and, retro-bulbar hematoma) that can occur if there is injury to the AEA or its surrounding area [7]. Moreover, many authors mentioned that AEA is a good anatomical landmark to locate the frontal recess, which aids in both frontal and ethmoid sinus surgery as well as for the localization the skull base in endonasal surgery [1, 2, 4].
Nowadays, CT can serve as an anatomic map for the surgeon and it is mandatory for the assessment of the nasal cavity and the paranasal sinuses regarding its anatomy as well as its pathology [14]. CT scan is broadly prescribed by surgeon prior to do sinus surgery as it overcomes the other radiological studies by the ability to define the bony structures of the nasal cavity and sinuses, so almost all surgeon asked this type of image ( coronal CT scan of paranasal sinuses) in order to evaluate the complex anatomy of the nasal cavity including the precise identification the site and course of the AEA in order to diminish the possible dangerous complications that they can face during operations.
Gotwald et al. evaluated 40 coronal plane CT exams and noticed that the AEF and the AES were found respectively in 95% and 84% of exams [11]. Noori et al. evaluated 145 coronal scans and noticed that AEF and AFS were noticed in 100% and 98% respectively [15]. Moreover, McDonald et al. studied 50 CT exams in the coronal plane and notices the AEF bilaterally in 95% of exams [16]. In our study, we found that AEF and AES were dependable landmarks on coronal CT scans to locate the AEA since they were noticed in 100% and 93.4% respectively.
In this study we have noticed the AEA canal in 36.8% of cases which was almost similar to Noori et al study where they found it in 33% of cases [15]. Moreover, Basak et al in his study observed the artery in 43% of exams [9]. On the other hand, Gotwald et al. who just rely on the structural cornerstones of the artery in paranasal sinus CT scans without directly visualizing the AEA, canal reported the possible orientation of AEA in 79% of their CT exams [11].
Also, in our study, the SOP was seen in 29.1% of cases, this rate is somewhat greater than that of Chung et al. and Noori et al that they reported visualization of supraorbital pneumatization in 26%, 28% respectively [15, 17]. Moreover, in a study by Cho et al, the incidence of SOP in a Korean population was 2.6%, while the incidence in a Western population was 64.4% [18]. In this study there was a strong correlation ship between the existence of SOP on paranasal coronal CT scans and visualization of the AEA canal. In other words, The AEA canal was seen in all exams in which SOP was present. These findings are consistent with Zhang et al who found that the AEA was always located posterior to the SOP. However, they reported only a 5.4% incidence of SOP in their study [19].
It was concluded that AEF (indentation existing on the lamina papyracea) and AES (indentation existing on the sidewall of the olfactory fossae) were prominent features on CT scan to detect the AEA canal and it was found in 100% and 93.4% of cases respectively. Furthermore, there was a statistically significant association between the existence of SOP on coronal paranasal sinus CT scans and the ability to visualize the AEA canal. In other words, the AEA canal was seen in all exams in which SOP was present on coronal CT scans of the paranasal sinus.