Apaper published recently in the BMJ reported results from a historical study of intellectual capacity in people receiving head and neck radiotherapy before the age of 18 months.1 Hall et al concluded that the severity of intellectual impairment was a dose dependent result of radiotherapy. They further commented that radiation doses associated with contemporary diagnostic computed tomography of the head were comparable with radiotherapy doses quoted from their study and concluded that this was a cause for concern. The “What this paper adds” box stated: “Diagnostic evaluation of children with minor head injuries by computed tomography needs to be re-evaluated.” We believe that the data presented in the paper do not support that conclusion. For “This week in the BMJ,” the chosen the headline was: “Computed tomography scanning in infancy may affect later learning.” This was unfortunate, as the paper did not address that topic. Equally unfortunately, the press releases to the media carried this message, which was subsequently published in many newspapers. Those of us working in paediatric imaging expected a deluge of inquiries from worried parents. We were not disappointed.

Radiology professionals are required to know the radiation burdens of x ray techniques used, which can be assessed by several different methods. Figures are usually quoted for effective whole body dose expressed in milliSievert (mSv), whereas in other situations individual organ doses are more appropriate, measured in milliGray (mGy). …