What is the difference between a CT scan and a chest x-ray?
An x-ray sends out a single beam of radiation, showing your doctor if there is a change in the shape of your heart (as in the case of heart failure, which causes the heart to become enlarged) or a problem with your lungs, such as pneumonia, pleurisy, or lung cancer. The CT scan sends out several beams of radiation at the same time, so it can provide more detailed information about organs (such as blood vessels in the heart).