Computed tomography (CT scans) in California children and pregnant women: Is use still increasing?

While exposure to ionizing radiation (IR) from medical sources, primarily computed tomography (CT), has risen over 700% in the 25 years ending 2006, recent trends are less clear. As IR from a pediatric CT scan is equivalent to that from 150 - 250 chest x-rays, and children are 2-10 times more sensitive to IR effects than adults, increasing exposures to children and pregnant women raise concern. Our objectives were to: 1) characterize CT trends in California hospitals and emergency departments (EDs), by demographic and utilization factors, for children and pregnant women from 2005 – 2010; 2) estimate scan doses and calculate lifetime attributable cancer risk per visit. Results showed hospital visits involving CT declined 21%. ED visits involving CT rose from 1.0% to 1.8% between 2005 and 2009, dropping slightly to 1.7% in 2010. Because these percentages differ from national estimates of around 5%, these preliminary results will be further reviewed. Over ¼ of hospital and 1/3 of ED patients received two or more scans per visit. Rates of CT use in hospitals were highest among infants <1 year, followed by adolescents aged 15-17. The CT rate among pregnant women nearly doubled, from 36 to 61 per 10,000 ED visits. Effective doses and lifetime attributable risk per visit, accounting for multiple scans, will be calculated. Depending on the procedure, doses may exceed annual natural background radiation. While the historical increase in CT use may be leveling, implications for individual and population health at these elevated levels of utilization merit further examination.