of mediastinal masses. Ultrasound has played a very minor role in imaging masses in this location, being utilized only in very anterior lesions or those immediately adjacent to the chest wall.In lower mediastinal masses, however, ultrasound can be superior to CT, both in differentiating cystic from solid lesions and in demonstrating diaphragmatic relationships. In the following case, ultrasound played a major role in the diagnosis of a bronchogenic cyst of the lower middle mediastinum.
FIGURE 1. A, 8:Posteroanterior and lateral chest films revealing a well-circumscribed mass behind the right heart border in the middle rnediastinum.