Surgical measurement to sphenoid sinus for the Chinese in Asia based on CT using sagittal reconstruction images.

The objective this study was to measure the changes of sphenoid sinusin the Chinese in AsiausingCT sagittal thin-slice reconstruction images, and to clarify the three-dimensional anatomical features of sphenoid sinus with its surrounding structures, relevant to the performing of the endoscopic sphenoidotomy. The sagittal reconstruction images were obtained from 178 CT images of 89 cases of normal adult participants (54 males and 35 females) with sphenoid sinus. We took the high-resolution axial CT images, from all the subjects, of the thickness by 0.625 mm, and reconstructed 1-mm-thick gapless sagittal CT images to measure the distance of all the sellar and pre-sellar types on the three-dimensional reconstructable sagittal plane under the bone window (4,000 at its width, and 400 at its level) in the CT images. The length of mean vertical line from the center of sphenoid ostium to the roof of sphenoid sinus of Non Onodi cell type is 10.6 ± 1.5 mm, and of Onodi cell type is 3.3 ± 1.5 mm. The length of vertical line from the center of sphenoid ostium to the lowest level of the bottom of sphenoid sinus is 12 mm ± 3.7 mm. The length of mean horizontal line from the sphenoid ostium to the posterior wall of sphenoid sinus is 18 ± 1.5 mm or 28 ± 2.5 mm. The mean horizontal line from the lowest point of the sella to the anterior wall of sphenoid sinus is 17.5 ± 1.3 mm in length. The mean horizontal distance from anterior wall to posterior wall of sphenoid sinus of Non Onodi cell type lining skull base is 10.1 ± 1.0 mm, and of Onodi cell type, is 5.2 ± 4.3 mm. The longest horizontal distance from the anterior wall to the posterior wall of sphenoid sinus is 22.0 ± 7.7 mm. The present study provides atomical information about sphenoid sinus of the Chinese in Asia with some surgical distance measured between the sphenoid ostium and the surrounding structures, which is essential to avoid the complications during surgery.