Evaluation of cardiac masses: the role of cardiovascular magnetic resonance.

Evaluation of known or suspected cardiac masses is a frequent and expanding indication for referral to the cardiac magnetic resonance (CMR) laboratory. Most patients will have undergone an initial echocardiogram that raised the suspicion of an abnormality. However, echocardiography suffers from several well-described limitations: restricted field of view; incomplete assessment of an invading cardiac mass due to an unfavourable patient body habitus; and limited ability to perform tissue characterization. The role of CMR in this setting is well established because of its ability to obtain a wide field of view, generate high contrast and spatial resolution, and perform multiplanar imaging, allowing precise demonstration and localization of a mass. In clinical practice, CMR serves several useful purposes. First, it is able to help discriminate between a true cardiac mass and a pseudomass. Second, tissue characterization by CMR can assist in generating a differential diagnosis, and can distinguish a cardiac neoplasm (which generally will require excision) from other conditions, such as intracardiac thrombus, lipomatous hypertrophy or benign lipomas (all of which generally do not require excision). Third, even when the etiology of a mass is known, CMR can provide useful information as to the extent of invasion into cardiac, as well as extracardiac structures, and associated findings. This article provides a general overview as to how CMR may be clinically useful to the practicing cardiovascular specialist.