Components of the PA mediastianl shadow (A) include SVC (1), ascending aorta (2), RA (3), IVC (4), aortic arch (5), pulmonary trunk (6), LA appendage (7), and LV (8).
Mediastinal compartments on the lateral film (B) include: superior (S), anterior (A), middle (M) and posterior (P) compartments.
Mediastinum