Peripheral QCT is associated with a low radiation dose because radiosensitive organs are distant from the primarily exposed area. Studies show that the effective dose from pQCT examinations is lower than 0.01 mSv [9, 14]. In a recent study of pQCT applied to imaging of microstructure of the distal tibia in adolescents, Burrows et al. reported an effective dose for HR pQCT (XtremeCT, Scanco) lower than 0.003 mSv [14]. Interestingly, these authors selected a measurement site so as to avoid primary irradiation of the growth plate. Dose optimisation is important even for low-dose methods as children and adolescents are more susceptible to the risk of radiation-induced biological effects than adults. However, the fact that both DXA and pQCT involve low radiation doses enables these techniques to be used to study the growth and development of the skeleton in normal children.