A group of Swedish scientists at the Karoliska Institute and Harvard School of Public Health have found that CT scanning in children could affect their later learning abilities. The British Medical Journal presents the study thus:
Receiving low doses of ionising radiation to the head in infancy may impair the developing brain and affect intellectual development. Hall and colleagues (p 19) studied 3094 men from Sweden who had received radiotherapy for cutaneous hemangioma before the age of 18 months. They analysed military records reporting the men’s intellectual capacity at age 18 or 19 and found that exposure to doses of radiation greater than 100 mGy, the equivalent of a computed tomography scan, was negatively correlated with high school attendance and learning ability assessed by cognitive tests. The authors call for re-evaluating the use of computed tomography for minor head injuries in infants.
The full text of the article Per Hall, Hans-Olov Adami, Dimitrios Trichopoulos, Nancy L Pedersen, Pagona Lagiou, Anders Ekbom, Martin Ingvar, Marie Lundell & Fredrik Granath, ”Effect of low doses of ionising radiation in infancy on cognitive function in adulthood: Swedish population based cohort study”, BMJ 2004;328:19 (3 January) is available at the BMJ web site. The study has already received some criticism at the Rapid Responses section.