Contrast agents in diagnostic imaging are substances used to enhance the contrast of structures or body fluids during diagnostic imaging examinations. The benefits of contrast agents help to accurately diagnose the pathology that needs to be examined.

Magnetic resonance angiography (MRA) of the thoracic aorta is a magnetic resonance imaging procedure focused on the thoracic aorta, which may or may not use contrast agents depending on the patient, to produce detailed images of the thoracic aorta, thereby helping to detect pathologies of the thoracic aorta.