August 2014

Dramatic advances in the practice of cardiovascular medicine have been paralleled by and made possible in part through similarly dramatic advances in the field of cardiac ultrasound. Cardiac ultrasound maintains a paramount role in daily practice essential for diagnosis and management. Echocardiography offers high sensitivity, portability, and lower cost compared with other imaging modalities, without the potential risks associated with ionizing radiation. Cardiac sonographers are increasingly requested to perform examinations on patients undergoing multiple procedures in rapid succession while hospitalized or in outpatient facilities. It is increasingly common that sonographers are exposed to radiation through participation in transesophageal echocardiography–assisted fluoroscopically guided procedures (TEEFPs) in the cardiac catheterization and electrophysiology laboratories and hybrid cardiac surgical suites, especially while performing studies on patients who were very recently injected with radioisotopes for myocardial perfusion imaging or other radionuclide studies. The radiation dose absorption and possible associated risks for sonographers performing transthoracic echocardiography (TTE) on patients made transiently radioactive shortly after undergoing myocardial perfusion imaging studies (nuclear stress tests) or participating with TEEFPs are inadequately addressed in the literature and unknown. There is conclusive evidence that the risk from exposure to high levels of radiation is quite real and can produce tissue reactions such as skin burns and cataracts, as well as stochastic effects such as cancers and damage to a fetus. The best current evidence suggests that there is no safe level of exposure to radiation, that even low doses can cause cancer, and that risks are generally proportional to dose. These guidelines address the issues faced by sonographers, define the usual circumstances of radiation exposure for sonographers, define how sonographers can minimize their radiation exposure, and offer a pathway to clarify for administrative leaders the risks sonographers face regarding their exposure to ionizing radiation.