Objective: To compare age groupings versus weight groupings in the calculation of typical air kerma area product (PKA) values in paediatric X-ray exams of chest and abdomen in our hospital. Methods: Data were analysed from 687 abdominal and 1374 chest X-ray examinations. The PKA of exams was extracted with Radimetrics, and patient weights were collected from electronic records. Data were organised in different age groups and typical PKA values were estimated. The process was repeated by organising data in different weight groups. Results: Typical PKA values for the four younger age groups (<1m, 1m - < 4y, 4y - < 10y and 10y - < 14y) were comparable to typical values for their equivalent weight groups (<5 kg, 5–15 kg, 15–30 kg and 30–50 kg, respectively). However, typical PKA values at the late adolescent age group (14y - < 18y) were much lower than its equivalent weight group (>50 kg). Conclusions: Age and weight groupings were found at our site to be interchangeable for the calculation of typical paediatric PKA values. The only exception was the late adolescent group, whose weight distribution can account for the difference in typical PKA results within its equivalent weight group. Advances in knowledge: In calculating typical PKA values for radiological paediatric body examinations, departments must ascertain if using age groups, which is typical practice, is equivalent to using weight groups. Otherwise, results may misrepresent local practice.

We describe the technical evaluation of the commercially available, clinical, biplanar, low dose, digital X-ray system (EOS System, EOS imaging, France). The unit is used for upright, weight-bearing musculoskeletal pathologies, in particular, in the spine and lower limbs. The evaluation incorporated tests on the X-ray generator performance, radiation/imaging field alignment, dose area product accuracy and image quality. The assessment methodology was based on objective parameters and required equipment readily available for technical evaluation of other radiological equipment. Results demonstrated that the system performs well within acceptable performance criteria with regard to X-ray generator performance, radiation/imaging field alignment and dose area product accuracy. In addition, results from the image-quality assessment were aligned with previously published work. The work presented in this article can be used for the technical evaluation of the EOS System at other clinical sites.