Reduced-Radiation Heart Scans Don't Compromise on Quality
New techniques bring equivalent results without the potential dangers, study shows
TUESDAY, June 9, 2009 (HealthDay News) -- Researchers say they've developed new techniques for reducing radiation exposures from the scans used to diagnose heart disease.
The use of these radiation-lowering strategies did not affect the quality of images gleaned from cardiac computed tomography angiography (CCTA), an increasingly popular weapon in the war against heart disease, say researchers reporting in the June 10 issue of the Journal of the American Medical Association.
Coronary artery disease is the leading cause of death in the developed world and rates are increasing among developing nations.
As rates have increased, health care systems are under pressure to find cost-effective means of diagnosing coronary ischemia, or insufficient blood flow through the arteries.
CCTA has the potential to be a part of the solution, researchers wrote. Unlike other means of diagnosing coronary artery disease, such as cardiac catheterization, CCTA is non-invasive.
Yet exposing patients to radiation remains a concern, said researchers from William Beaumont Hospital in Royal Oak, Mich.
They tested several techniques to lower radiation exposure, including minimized scan range, heart rate reduction, electrocardiographic-gated tube current modulation and reduced tube voltage in suitable patients.
Participants included almost 4,900 patients undergoing CCTA at 15 hospital imaging centers ranging from small community hospitals to large academic centers.
In the months after the new techniques were put into effect, the median estimated radiation dose was reduced by 53.3 percent. In addition, more patients had radiation exposure levels that were lower than a target amount set by the researchers.
The most effective technique for lowering radiation exposure was using lower tube voltage. Among patient-related variables, lower heart rate was also associated with a smaller radiation dose.
"Importantly, despite the reduction in radiation doses, there were no significant differences during the control period compared with follow-up period in median image quality rating or the proportion of diagnostic-quality scans," researchers wrote.
Researchers recommended that physicians and other hospital personnel learn strategies for reducing radiation exposure.
The importance of radiation-reduction techniques must be emphasized during physician and technologist training, and physicians should demonstrate technical mastery of these methods before certification to oversee CCTA scanning, they wrote.
The University of Wisconsin has more on CCTA.