Patterns of Pleural Reflections of the Left Superior Mediastinum

Routine postero-anterior chest radiographs were analyzed in 278 subjects with no known mediastinal disease to determine the normal configuration of the mediastinum between the level of the left main bronchus and the aortic arch. Five recurring contour patterns were defined. These patterns are due to pleural reflections which lie in close relationship to the left prevascular group of anterior mediastinal lymph nodes. Diagnosis of mediastinal adenopathy can be made based on small departures from the normal patterns. Changes occurring between initial and follow-up radiographs are particularly significant.