American College of Radiology clinical statement on noninvasive cardiac imaging.

Coronary artery disease (CAD) and other acquired and congenital cardiac diseases are major medical and socioeconomic problems. CAD affects 13.2 million Americans and was responsible for 502 189 deaths in 2001. In 2004, the direct and indirect economic impact of CAD was in excess of $120 billion, which was about one-third of the total costs attributable to cardiovascular diseases (1). Historically, imaging has had a critical role in the diagnosis and evaluation of acquired and congenital cardiac disease, beginning with chest radiography and fluoroscopy and progressing to coronary angiography and cardiac catheterization, ultrasonography (echocardiography), and nuclear medicine. All of these modalities have a well-established role in patient care. Computed tomography (CT), with multidetector CT and electron-beam technology, and magnetic resonance (MR) imaging, with appropriately equipped imagers, now can image the coronary arteries, cardiac chambers, valves, myocardium, and pericardium and can help assess cardiac function. Thus, CT and MR imaging will have an increasing role in comprehensive cardiac imaging. While the technical parameters and field of view of a cardiac CT or MR examination will appropriately be tailored to help evaluate the cardiac anatomy and/or function in question, the images obtained will demonstrate adjacent anatomy, often including portions of the lungs, mediastinum, spine, and upper abdomen. It has been documented that these studies often demonstrate clinically significant noncardiac findings (2,3). In addition to examining the cardiac structures of interest, the interpreting physician is responsible for examining all the visualized noncardiac structures and must report any clinically relevant abnormalities of these adjacent structures. In some cases, these structures may be seen only on localizing (scout) images. Cardiac CT and cardiac MR imaging each present potential patient safety issues. Cardiac CT safety issues are related to radiation exposure and to administration of intravascular (IV) contrast media. The safety concerns for cardiac MR imaging are primarily related to the strong magnetic field and its potential effect on implanted devices, but MR imaging contrast agents and patient sedation also present potential safety issues. In addition, pharmacologic agents may be administered for either CT or MR imaging examinations. Radiologists, because of their extensive experience in CT and MR imaging, have an important role in imaging of cardiac patients with these modalities. Most radiologists already supervise the performance of CT and interpret CT scans of the chest (including basic evaluation of the pericardium, heart size, and cardiac masses) and CT angiographic and MR angiographic images. Their knowledge of structures beyond the heart provides added value in cardiac imaging. They already oversee CT and MR imaging equipment and personnel. Their experience with the techniques now being applied to the heart provides expertise to develop specific cardiac applications of CT and Published online before print 10.1148/radiol.2353050358 Radiology 2005; 235:723–727