Abstract
OBJECTIVE: To compare age groupings versus weight groupings in the calculation of typical air kerma area product (P(KA)) 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 P(KA) of exams was extracted with Radimetrics, and patient weights were collected from electronic records. Data were organised in different age groups and typical P(KA) values were estimated. The process was repeated by organising data in different weight groups. RESULTS: Typical P(KA) 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 P(KA) 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 P(KA) values. The only exception was the late adolescent group, whose weight distribution can account for the difference in typical P(KA) results within its equivalent weight group. ADVANCES IN KNOWLEDGE: In calculating typical P(KA) 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.