Superior Mediastinal Cut-off Measurements in Chest Radiographs for Screening of Silent Thoracic Aortic Diseases

Objective: To determine cut-off values for superior mediastinal width and the mediastinal width-to-thoracic cage ratio from chest radiographs for the early detection of unrecognized thoracic aortic diseases. Additionally, this study aims to enhance diagnostic strategies for identifying aortic abnormalities. Materials and Methods: This retrospective analysis included 152 subjects who underwent both computed tomography angiography (CTA) of the thoracic aorta and chest radiograph between April 2007 and January 2021. Superior mediastinal width was measured at 3 levels on chest radiographs. Thoracic CTA findings were categorized into normal and abnormal groups, the latter comprising aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, and aneurysm. Cut-off values for superior mediastinal width and the mediastinal width-to-thoracic cage ratio were calculated using receiver operating characteristic (ROC) curve analysis. Results: The optimal cut-off values were a mediastinal width ≥ 8.4 cm at the aortic knob level (ROC 77.3, 95% CI: 69.8-84.9, P Conclusion: The established superior mediastinal width and ratio cut-off values from chest radiographs can help clinicians identify patients at risk for silent thoracic aortic disease, prompting further CTA evaluation that can prevent fatal outcomes and improve patient’s quality of life.