CT Imaging of the Azygos Lobe: Prevalence and Clinical Implications

INTRODUCTION: Azygos lobe is a rare anatomical variation in the upper lobe of the right lung. It is visible on chest radiography or computed tomography (CT) scans. In this study, we aimed to investigate the prevalence and sex distribution of the right azygos lobe in patients undergoing thoracic CT in a local region of the Eastern Black Sea in 2020.
METHODS: In this study, we retrospectively examined the images of 10,271 patients with thorax CT scans between 2020 and 2021. The ages and sex of the patients were recorded. The azygos fissure was identified as a convex line in the paramediastinal portion of the upper lobe of the right lung. The presence or absence of the right azygos lobe and fissure and the presence of a lung mass or nodule inside the azygos lobe were examined in patients undergoing thoracic CT.
RESULTS: The azygos lobe was found in 51 (1%) females and 73 (1.4%) males out of 10,271 patients examined. Azygos lobe was found in 124 patients (1.2%). The study results indicated that males had a higher prevalence of azygos lobe variation than females. However, there was no statistically significant relationship between the presence of azygos lobe variation and sex (p = 0.13). This study revealed no masses or nodules in the azygos lobe.
DISCUSSION AND CONCLUSION: The present study reports on the prevalence and sex distribution of the azygos lobe in a large representative sample of the Eastern Black Sea region, highlighting the importance of accurately detecting the azygos lobe in imaging studies.