The establishment of reference doses in paediatric radiology as a function of patient size

There is a wide range in paediatric patient size from a newborn baby to a 15-year-old adolescent. Reference doses for paediatric radiology can sensibly be established only for specific sizes of children. Five standard sizes of patient have been chosen at ages 0 (newborn), 1, 5, 10 and 15 years. Standard AP and lateral thicknesses for the head and trunk for the reference ages were derived from published measurements on children. Normalisation factors for entrance surface dose and dose-area product measurements were calculated which depend on the thickness of the real patient, the thickness of the nearest standard 'patient', and an effective linear attenuation coefficient (μ). These normalisation factors were applied to European data to derive some preliminary reference doses.