. True statement regarding cardiac tamponate

Radiation-induced pericardial effusion may be the main cause of enlargement of the cardiac silhouette. The irradiated cardiac area was the only significant risk factor for enlargement of the cardiac silhouette; the use of chemotherapy was not. Enlarged cardiac silhouette could be pericardial effusion or cardiac enlargement or cardiac tamponade. Dorsally displaced epicardial fat pad (arrows) indicates that the cardiac silhouette is due to pericardial effusion. Ref Davidson 23rd edtion pg 466