Radiation exposure in diagnostic imaging: wisdom and prudence, but still a lot to understand.

Since 2000, a series of scientific articles on CT have been raising increasing concern about the risk of radiation induced cancer in children. The alarming conclusions of some of these articles had international echo through global media, provoking widespread public concern. Actually, many of these alarming scientific publications appeared to be flawed by poor study design, but their conclusions were not openly contradicted. In US and Europe pediatric radiologists had to face a huge challenge, which brought to the Image Gently campaign and the Eurosafe initiative with the aim to rebut misinformation and to support medical radiation protection. The Linear No Threshold model-which is the base of contemporary radioprotection-is increasingly questioned by new recent studies suggesting that low dose radiation would decrease cancer risk thanks to the enhancement of immune system response. Actually, pediatric radiologists have to cope with many important issues and contradictory messages. Good medical practice includes good communication about the benefits and risks of health procedures, thus the communication of radiation risk is a key component for radiologists. When considering benefits and risks, an important risk is too often ignored: the risk that skipping a diagnostic exam may cause a misdiagnosis, and therefore, a poor outcome. We should emphasize that a risk from a radiological investigation is very small, if a risk at all, and we are not sure that there is a risk at very low doses, like those doses in the majority of X-ray procedures including CT.