Radiation reduction in the congenital Cardiac Catheterization Laboratory

The use of ionizing radiation is a necessary component of procedures in the cardiac catheterization laboratory. Individuals with congenital heart disease typically are diagnosed as children or young adults and may undergo many imaging studies involving radiation exposure over their lifetimes.

Pediatric cardiologists at Mayo Clinic in Rochester, Minn., are working to minimize radiation exposure to patients while maintaining appropriate image quality. Their efforts are resulting in lower radiation exposure for all patients undergoing diagnostic and interventional procedures in the cardiac catheterization laboratory.

Beginning in 2008, 11 intentional practice changes were implemented involving the pediatric and adult congenital practice. These changes included both technical alterations related to image acquisition as well as provider education. The impact of these changes on all imaging studies in pediatric and adult congenital patients over a 45-month period was reviewed by Daniel A. Mauriello, M.D., a fellow in pediatric cardiology at Mayo Clinic in Minnesota.

Studies were classified based on procedure type and complexity, and patients were classified based on size and age. Logarithmic changes of the cumulative air kerma (Kar), which is the absorbed dose delivered in the absence of scatter (measured in Gy), were modeled. "The practice changes implemented resulted in a dramatic 61 percent decrease in radiation exposure across the entirety of the practice," according to Kenneth A. Fetterly, Ph.D., a radiation physicist at Mayo Clinic in Minnesota.

Subanalysis showed the greatest reduction (74 percent of Kar) in those patients undergoing simple interventions (atrial septal defect/patent foramen ovale closure, pulmonary valvuloplasty, and patent ductus arteriosus closure). Those patients undergoing noninterventional procedures (hemodynamic catheterization and right ventricular biopsy) also saw a robust 71 percent decrease in Kar over the study period.

Analyses of weight and age as independent variables revealed that the greatest reductions in Kar were in individuals weighing 20 to 60 kg (72 percent) and those ages 10 to 17 years old (74 percent).

"Through a combination of technical changes and provider awareness initiatives, we have been able to dramatically reduce the radiation exposure to the majority of patients undergoing procedures in the pediatric and congenital catheterization laboratory," says Allison Cabalka, M.D., a pediatric cardiologist at Mayo Clinic in Minnesota and director of the pediatric and congenital Cardiac Catheterization Laboratory. Continued efforts to minimize radiation exposure to patients are an important part of Mayo Clinic's commitment to safety.