COMPARISON OF A HETEROGENEOUS CHILD PHANTOM WITH PEDIATRIC-PATIENTS

In the optimisation of roentgen diagnostic procedures phantoms are oft en used for image quality assessment and/or dosimetry. In paediatric r adiology phantoms are rare. In this work an anthropomorphic phantom fo r dosimetry simulating a one-year-old child is compared to real patien ts using clinical CT images of paediatric patients and Monte Carlo cal culations of depth doses. The results indicate that the absorbed doses in paediatric patients are within 35% of the dose values received fro m measurements in the phantom and that effective dose calculated for t he phantom should correspond within 20% to the effective dose for a pa ediatric patient. Between the lung tissue of the phantom and ICRU lung tissue of the same density, the calculated differences in absorbed do se are at most 9% for the energy spectra used (60 kV and 120 kV) and d epths from 0 to 10 cm. Among lungs with different densities the differ ences in absorbed dose are larger.