Evaluation of Paranasal Sinus Variations with Computed Tomography

INTRODUCTION: Paranasal sinuses are one of the most common anatomical variations in humans. Computed tomography (CT) is an imaging modality used as the gold standard in the evaluation of patients before endoscopic sinus surgery (ESS). This study aims to evaluate the anatomic variations that should be considered before and during the surgical procedure by CT examination and to determine their frequency.
METHODS: In this study, the images of patients who were referred to the otorhinolaryngology (ENT) outpatient clinic, considering that they had had sinus pathology and underwent paranasal sinus CT imaging were retrospectively analyzed. A total of 320 patients aged between 15-90 years were evaluated. Non-contrast images obtained by multislice CT were examined. The breakdown of anatomic variations evaluated in CT sections obtained according to these protocols is presented in Table 1.
RESULTS: Of the 300 patients, 151 were male (47.2%) and 169 were female (52.8%). The mean age was 39.8±15.8 years. The most common anatomic variation was agger nasi cell with 86.3% (n=276). The least detected anatomical variations were pneumatized inferior turbinate and bifid inferior turbinate as 0% (n=0), inferior turbinate hypoplasia as 0.3% (n=1), and bifid uncinate process variations as 0.6% (n=2).
DISCUSSION AND CONCLUSION: Considering that a significant portion of the variations identified in this study (such as ICA protrusion and dehiscence, ethmoid roof asymmetry, Onodi cell, atelectatic UP) may lead to significant complications during surgery, it is important to know and describe the appearance of these variations on CT. In our study, significant variation was observed in the sinonasal region, and it was once again emphasized that paranasal sinus CT was very valuable in determining these variations.