ABSTRACT
Cardiothoracic ratio (CTR) is usually expressed as the ratio of these measurements. CTR of greater than 0.5 is said to indicate cardiac enlargement although there are a number of variables, not least of which is the shape of the patient’s chest. Mitral valve leaflet or annulus calcification is seen on the lateral CXR inferior to a line from the carina to the anterior costophrenic angle, and on the pulmonary artery CXR inferior to a line from the right cardiophrenic angle to the left hilum. CXR and echocardiography are the usual imaging tests employed for the initial assessment of Congestive cardiac failure (CCF). Coronary artery imaging with computed tomography or angiography is indicated where an ischaemic cause for CCF is suspected. CXR is performed in the initial assessment of the patient with chest pain. In the context of suspected aortic dissection, CXR is mainly to exclude other causes of chest pain prior to more definitive investigation.
