Revisiting thoracic surface anatomy in an adult population:a Ct evaluation of vertebral level

Introduction: To compare key thoracic anatomical surface landmarks between healthy and patient adult populations using Computed Tomography (CT).Materials and Methods: Sixteen slice CT images of 250 age and gender matched healthy individuals and 99 patients with lung parenchymal disease were analyzed to determine the relationship of 17 thoracic structures and their vertebral levels using a 32-bit Radiant DICOM viewer. The structures studied were: aortic hiatus, azygos vein, brachiocephalic artery, gastroesophageal junction, left and right common carotid arteries, left and right subclavian arteries, pulmonary trunk bifurcation, superior vena cava junction with the right atrium, carina, cardiac apex, manubriosternal junction, xiphisternal joint, inferior vena cava (IVC) crossing the diaphragm, aortic arch and junction of brachiocephalic veins.Results: The surface anatomy of all structures varied among individuals with no significant effect of age. Binary logistic regression analysis showed a significant association between individual health status and vertebral level for: brachiocephalic artery (p=0.049), gastroesophageal junction (p=0.020), right common carotid (p=0.009) and subclavian arteries (p=0.009), pulmonary trunk bifurcation (p=0.049), carina (p=0.004), and IVC crossing the diaphragm (p=0.025).Conclusion: These observations differ from those reported in a healthy white Caucasian population and from the vertebral levels of the IVC, esophagus and aorta crossing the diaphragm in an Iranian population. The differences observed in the current study provide insight into the effect of lung pathology on specific thoracic structures and their vertebral levels. Further studies are needed to determine whether these are general changes or pathology-specific.