Tasheema Prince | American Journal of Hematology/Oncology

Patients' radiation exposure from scans used to diagnose coronary artery disease may be lowered without affecting the quality of the images produced, according to a study published in JAMA (2009:301:2340-2348).

Cardiac computed tomography angiography (CCTA) is a noninvasive test used to diagnose coronary artery disease, and although it is effective and efficient in identifying coronary artery disease, radiation dose from the procedure is of concern.

To determine whether an intervention to improve CCTA would lead to a reduction in exposure to radiation and not have an effect on image quality, Gilbert L. Raff, MD of William Beaumont Hospital in Royal Oak, Michigan and colleagues conducted a study of 4995 patients undergoing CCTA. Intervention efforts included use of techniques to reduce radiation dose, including minimized scan range, heart rate reduction, electrocardiographic-gated tube current modulation, and reduced tube voltage in suitable patients.

The study revealed that compared with the control period, patients' average estimated radiation dose was reduced by 53.3%, with no significant changes in average image quality rating or the proportion of scans usable for making diagnoses.

According to the press release announcing the study, the most powerful factors associated with achievement of the target radiation dose were the use of lower tube voltage, which increased from 13% to 43% of cases.

"Baseline data obtained in this study support the concern that CCTA testing may result in relatively high radiation doses, but the rapid improvement in radiation dose in the first 3 intervention months demonstrates how use of existing technology and technical methods is associated with dramatically reduced dosages," the researchers wrote.