Paediatric Imaging

Cardiomegaly

enlargement of the heart, that may be due to both cardiac and non-cardiac causes. In general the cardiac silhouette should occupy approximately 60% of the neonatal thorax while in older children about 50% of the thorax. Both anteroposterior and lateral chest radiographs are useful in determining specific chamber enlargement.

Right atrium enlargement appears as bulging of the right cardiac border on the frontal chest film.

Right ventricle enlargement results in an upward displacement of the cardiac apex on the frontal chest film. On the lateral film, the right ventricular chamber height is more than one third of the distance from the xiphisternum to the angle of Louis.

Left atrium enlargement on the frontal chest film may demonstrate elevation of the left main bronchus and double density of the left atrial enlargement beneath the carina.

Left ventricle enlargement is seen on the frontal chest radiograph as downward and left lateral displacement of the cardiac apex. On the lateral film, the left ventricle projects into the retrocardiac space posterior to the inferior vena cava.

LT