Figure 031_6138.

A patient with subtle pneumomediastinum, hardly seen on posteroanterior (PA) chest radiographs (A), that is identified on the basis of a thin radiolucent line highlighting the contour of the aorta (arrows) on the left lateral view (B). This finding represents air in the mediastinal soft tissue.

Figure 031_6138.  A patient with subtle pneumomediastinum, hardly seen on posteroanterior (PA) chest radiographs ( A ), that is identified on the basis of a thin radiolucent line highlighting the contour of the aorta (arrows) on the left lateral view ( B ). This finding represents air in the mediastinal soft tissue.