Figure 20b.  Pleuromediastinal cutaneous fistula in a 51-year-old man who developed coagulase-negative staphylococcal sternal wound infection 10 days after cardiac transplantation. (a) CT scan shows subcutaneous emphysema in the left chest wall. (b) Nonenhanced CT scan obtained inferior to a shows air in the sternal dehiscence and in infiltrated anterior mediastinal fat, findings consistent with infection. (c) CT scan obtained inferior to b shows more extensive pneumomediastinum and a right pneumothorax.