Exposure to imaging procedures may pose health risk to children

Use of medical diagnostic or therapeutic imaging procedures in children requires balancing the long-term risks of ionizing radiation exposure with the necessity of making clinical decisions, according to a study published in the Archives of Pediatric and Adolescent Medicine.

Researchers investigated a retrospective cohort of 355,000 patients younger than 18 years who were continuously enrolled in 5 regional markets of a large US health care provider between January 2005 and December 2007 for claims identifying imaging procedures using radiation exposure. Procedures were included for diagnostic or therapeutic (interventional) indications: plain radiography, computed tomography (CT) scans, fluoroscopy and/or angiography, and nuclear medicine scans. Anatomic areas of focus included chest and cardiac imaging; abdomen; pelvis; extremities; head and neck, including brain imaging; multiple areas, including whole body scans; and nonspecified areas.

Data showed that during the 3-year study period, 42.5% of the children underwent at least 1 imaging procedure, 25.2% underwent 2 or more procedures, and 16% underwent 3 or more. The highest annual rates of use generally were for children aged 10 years and older and were higher among boys than girls (44.4% vs 40.6%, respectively).

Plain radiography was the most common procedure among the children (39.8% received at least 1 plain radiographic examination; 22.3% received 2 or more), followed in frequency by CT scans (7.9% received at least 1 CT scan; 3.5% underwent 2 or more CT scans), fluoroscope/angiograph procedures (2.1% received at least 1 procedure), and nuclear medicine scans (0.7% received at least 1 scan). Use of CT scans, most commonly of the head, was higher overall in older children, accounting for 17.6% of all imaging studies in children aged 15 years to younger than 18 years. Use of imaging procedures in infants younger than 2 years also was frequent (9%).

Based on these data, the researchers said, the average child in this study population will have received more than 7 imaging procedures by the time he or she reaches the age of 18 years.

Because studies suggest that the hazards of radiation may be greater in children than adults, because in part of children’s growing tissues and longer life expectancy that allow more time for latent effects to emerge, the investigators advise clinicians to be aware that the concept of ALARA (as low as reasonably achievable) should be applied to the use of imaging procedures with ionizing radiation in children.

Researchers noted that they did not know the clinical context under which the imaging procedures in the study were ordered; instead, they focused on describing patterns of use in order to provide critical information for policy makers and health care providers. “These results highlight the importance of generating databased guidelines to aid clinicians in determining the appropriateness of performing imaging procedures in children,” they said.

Dorfman AL, Fazel R, Einstein AJ, et al. Use of medical imaging procedures with ionizing radiation in children: a population-based study. Arch Pediatr Adolesc Med. 2011. Epub ahead of print.