Rib Abnormalities Investigated by Computed Tomography: A Report on Common and Uncommon Cases

Purpose: Rib anomalies include numerical and structural categories. This study investigates the costal abnormalities by computed tomography scan in an Iranian population. Methods: In a retrospective study, 400 Chest CT scans (225 (56.2%) male, and 175 (43.8%) female) aging from 18 to 89 were investigated for one year (2020 to 2021). Images were carefully observed and various abnormalities such as cervical ribs, elongated C7 transverse processes, bridging ribs, and bifid ribs are reported. Results: Among 400 chest CT scans investigated for this study, 375 (93.7%) cases were normal and 25 (6.3%) cases were abnormal. Fourteen (8% of all the female patients) and eleven (4.9% of all the male patients) participants of abnormal cases were female, and male, respectively. Among abnormal cases, four cases of bilateral cervical ribs (total prevalence (TP)=1%), four cases of bilateral elongated C7 transverse process (TP=1%), four cases of bridging first and second ribs on the left side (TP=1%), twelve cases of bifid ribs on the left (TP=3%), and one uncommon male case were reported. Conclusion: Being aware of the common abnormalities of rib cage is helpful in differentiating the diagnosis and seeking for possible other accompanied diseases such as thoracic outlet or Gorlin syndrome. In this study, twenty five cases of abnormal rib morphology were reported.