Evaluation of the variations of paranasal sinuses and nasal cavity by computed tomography

Introduction and Objective:Advances in the paranasal sinus surgery in recent years neccessiate detailed knowledge of the regional anatomy and evaluation of any pathology in detail. Nowadays, endoscopic sinus surgery (ESS) is the most widely used treatment modality in paranasal sınus diseases. The most important factor affecting the results and complications of ESS is the anatomic orientation of the ENT surgeon. Sinonasal cavity is one of the regions in the human body in which anatomic variations are mostly encountered and these variations play a major role in the etiopathogenesis of the sinuse inflammation.With the advantages and capabilities of obtaining high resolution multiplanar reformation CT images inherent in the developing multidedector CT technology, paranasal sinus CT has become the gold Standard in evaluation of the patients before ESS. In many radiological studies. It has been shown that the anatomic variations could be safely detected by CT. The radiologist should know the normal anatomy and relevant variations and report to the surgeon the sinonasal cavity disease as well as the variations if any in the preoperative period. This will result in the selection of the most approppriate surgical method with safe surgical procedures as well as minimizing the risk of complications.The aim of this study was to investigate the incidence of anatomical variations in the sinonasal cavity by CT scanning to avoid potential complications of the endoscopic sinus surgery and to reveal their frequencies in our region.Materials and Methods: Three hundred and twenty patients who were admitted to our Otorhinolaryngology outpatient Department between Oct 2008- August 2011 with clinical evidense of sinonasal pathology and had paranasal CT studies were included to this study.Results: We found that the most frequently encountered anatomical variation was agger nasi cells in 86.3 % (n=276), the least encountered anatomical variations were pneumatization and bifi of the inferior concha in our study. It was concluded that some of the anatomical variations cause complications during surgery if they can not be determined in the preoperative term, some of the anatomical variations predispoze problems of the mucociliary drainage and ventilation, and some of the anatomical variations have no clinical importance in this study.Conclusion: In our study, we found a great number of anatomical variations of sinonasal cavity in accordance with literature and we emphasize once more that paranasal sinus is unargued gold standard technique for identification of these anatomic variations.