Contrast agents used in cardiovascular magnetic resonance imaging: current issues and future directions

Cardiovascular MRI is being increasingly used in the evaluation of ischemic heart disease, cardiac masses, complex congenital heart disease, and morphologic evaluation of the vascular anatomy throughout the body. Many and varied contrast media may be used to increase the sensitivity and specificity of detecting and evaluating various pathologies, and a knowledge of the different mechanisms of action, distributions and safety profiles of these agents is required for safe and effective imaging. This article reviews the currently available magnetic resonance (MR) contrast media, discusses the risks and benefits, and gives illustrated examples of current clinical applications in cardiovascular disease. A literature search covered the period 1990 to the present with the use of multiple databases including MEDLINE, PUBMED, SciSearch and Google Medical. All identified studies containing information relevant to the topic of cardiovascular MRI and cardiovascular MR contrast agents and their uses and properties were evaluated. Evaluation was limited to studies in English. The conclusions were that the use of contrast agents vastly increases the diagnostic yield, sensitivity and specificity of cardiovascular MRI in the non-invasive diagnosis of the full breadth of cardiovascular pathology. The use of contrast MRI for investigating ischemic heart disease, cardiac masses, and congenital heart disease and in angiography is now well established, and the referring physician, cardiologist, or radiologist requires an in-depth knowledge of the safety profiles and correct dosing of commonly prescribed contrast agents. As the number of MR contrast agents on the market continues to increase, knowledge of the basic mechanism of action is vital for keeping abreast of how new and emerging agents will affect clinical practice in the future.