Cardiovascular experts issue blueprint for safer X-Ray imaging

Dec 8 2004

Millions of invasive cardiovascular procedures that involve the use of potentially hazardous X-rays are done in the United States each year.

Now, new competence standards written by a task force of experts from the American College of Cardiology (ACC), the American Heart Association (AHA), the NASPE-Heart Rhythm Society (NASPE-HRS), and the Society for Cardiovascular Angiography and Interventions (SCAI) will help ensure that the growing number of physicians who perform such fluoroscopically-guided procedures have the knowledge to do them competently, and with the least amount of risk to their patients.

Recent reports of radiation-induced injury to patients undergoing cardiac catheterization, coronary angiography, electrophysiology studies, and other fluoroscopically-guided procedures, have highlighted the risks associated with the X-ray imaging techniques that make these procedures possible. One of the purposes of the new document is to remind practitioners of these risks, John W. Hirshfeld Jr., M.D., chair of the competence standards writing committee, said. “The capability and complexity of invasive cardiovascular procedures have increased substantially. But as procedures have become more complex, they may last longer, thereby increasing the potential for greater patient exposure to radiation. We want to call the attention of physicians who use X-ray fluoroscopy to the risk and hazard of patient radiation injury.”

Carl Tommaso, M.D., SCAI Past President and co-author of the competence document, agreed. “Fluoroscopic imaging techniques have helped us to make great strides in treating cardiovascular disease and preventing life-threatening events, but they are not without risk. Other documents have addressed how to protect the physicians and staff involved in these procedures, but this is the first comprehensive set of recommendations aimed specifically at patient safety during fluoroscopically-guided procedures. This statement will supplement cardiovascular training programs and provide a reference for interventionalists in practice,” Dr. Tommaso said.

The document gives practical information on the physics and principles of X-rays, guidelines for determining safe and effective X-ray doses and exposure, and offers suggestions to help practitioners balance the risks and benefits of radiation for patients undergoing these fluoroscopically-guided procedures.

Acute awareness of the hazards of radiation may have diminished because of the frequency of the procedures and the increased numbers of physicians who are doing them. This makes the need for such a document very timely, said Mark A. Creager, M.D., chair of the competence standards task force.

“There are so many cardiovascular physicians, including coronary interventionalists, electrophysiologists, as well as other disciplines, such as vascular surgery, engaged in invasive cardiovascular procedures, that in their quest to perform the procedures and achieve an outstanding outcome, the fundamentals of X-ray and understanding of the appropriate use of X-rays safely and efficiently are often overlooked,” said Dr. Creager.

Besides information on the physics and nature of X-rays, the document also contains chapters on principles of X-ray image formation, operation of an X-ray cinefluorographic unit, determinants of patient X-ray dose, patient effects of X-ray exposure, radiation risks from typical invasive cardiovascular procedures, and physician responsibilities to patients. It also suggests a radiation safety curriculum for physicians who perform invasive cardiac procedures.

Key safety practices include proper calibration and maintenance of X-ray equipment, non-wavering attention to duration of radiation exposure, and knowing how to program the equipment so that it uses the least amount of radiation possible to do the job. “Some modes use more radiation than others, so we should always try to use the mode that will give a satisfactory image that uses the least radiation. Also the size of the radiation field in which you deliver radiation to the patient should never be any larger than the structures that you are trying to image,” Dr. Hirshfeld said.

The ACC recognizes that it has an important responsibility to help their members learn how to use fluoroscopic equipment in a way that will minimize risks, added Dr. Hirshfeld. “This paper has been written in the interest of developing optimal patient care and optimal patient safety. It is part of the College’s mission to facilitate this.”

“This is an extremely important document that really provides the guidelines for the knowledge base that physicians engaged in fluorscopically-guided invasive cardiovascular procedures must possess in order to competently and safely utilize X-ray imaging techniques to diagnose and treat patients with cardiovascular disease,” Dr. Creager said.