الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The vidian canal, the conduit through the sphenoid bone for the vidian nerve and artery, has become an important landmark in surgical approaches to the cranial base. The paired vidian canals are located in the skull base along the line of fusion of the pterygoid process and body of the sphenoid bone. The canal opens anteriorly into the medial part of the pterygopalatine fossa and posteriorly at the upper part of the anterolateral edge of the foramen lacerum. The vidian nerve, when followed posteriorly, reaches the lateral surface of the anterior genu of the petrous carotid and the anteromedial part of the cavernous sinus, where the nerve is continuous with the greater petrosal nerve.
The vidian canal (VC) and its contents are known to be a consistent and reliable surgical landmark to the petrous ICA, allowing its identification at the point of transition from the horizontal petrous to the vertical paraclival segment of ICA at the level of the foramen lacerum (FL).(9,11,12)
The literature is lacking a profound anatomical description of this complex area. Furthermore racial differences in the pneumatization pattern of the sphenoid sinus was detected, and these differences might make the EEAs more dangerous in one population than another. Thus a comprehensive anatomical knowledge is paramount to achieve efficiency and safety during endoscopic endonasal approaches in this region.(104) The goal of this study in Egyptian population was to demonstrate vidian canal localization, its length and its position in relation to the anterior nasal spine, floor of nose, and petrous segment of the ICA, by using CT images.
This study was performed on CT scans of 100 adult patients (50 males and 50 females), selected from the patients admitted for sinonasal symptomatology and underwent the investigation for various suspected paranasal diseases but were found completely normal, without skull base pathology. Patients less than eighteen years old, or with proven paranasal pathology, and those who had prior surgery in paranasal areas and in pituitary fossa, or with nasal trauma were excluded.
All 200 vidian canals of the 100 cases included in this study were demonstrated and evaluated separately using a Multislice CT technique. Non contrast thin-collimation contiguous helical scanning with a maximum section thickness of 0.6 mm. Scans were reconstructed in the axial, coronal, and sagittal planes by using high resolution algorithm bone windows.