"post-radiation"
"ASD"
"In most cases, merely 'eye-balling' a chest x-ray will be sufficient in detecting cardiomegaly (as the heart is either clearly normal in size or clearly abnormally enlarged). In equivocal cases, the cardiothoracic ratio (CTR) can be easily calculated on an erect PA chest x-ray. The CTR measures the width of the cardiac silhouette and the thoracic cavity;"
"Ebstein anomaly"
"There are many aetiologies for cardiomegaly:"
"Specific cardiac chamber enlargement can be recognised by cardiac contour changes, new or different interfaces with adjacent lung, and/or displacement of adjacent mediastinal structures. These are discussed separately:"