Common anatomic variants simulating mediastinal pathology on chest radiographs: Confirmation with alternate imaging modalities

The chest radiograph is the most common imaging examination and usually the first study in any evaluation of thoracic disease. It is often obtained upon initial presentation to the emergency department. Unfortunately, because of its two-dimensional nature and limited contrast sensitivity, certain regions, such as the mediastinum are particularly difficult to evaluate. A number of anatomic variants in that compartment can mimic significant pathology. The subject of this review is the range of normal patterns and common mediastinal anomalies, including those from the osseous, gastrointestinal, and vascular systems, as well as the supporting stromal tissue. We also consider postoperative modifications of the mediastinal contours.