Abstrait

Evaluation of Phantom Equivalent Materials in Polychromatic Diagnostic X-Ray Beam

Radhakrishnan BN, Ramakrishnan G, Chandralingam S and Kurup PGG

Background: Many phantoms are available in the market for dosimetric and quality assurance studies of radio-diagnostic and radiotherapy equipment. These phantoms are quite expensive and are seldom available in many hospitals. Objective: The study is aimed to explore the suitability of few cost effective materials to substitute as phantoms for dosimetric study purposes. Materials & methods: Card board and sun mica sheets were used as sample materials. Virtual water or solid water phantom was considered as the standard. Mass attenuation coefficients (μ/ρ) were experimentally determined for these samples with diagnostic x-ray beam which were then correlated with the theoretical values for monoenergetic photons to estimate the effective energies of the interacting beams. The results were verified with SpekCalc program and the published data. Results and discussion: Cardboard and sun mica sheets exhibited μ/ρ values closer to virtual water. However, effective energies of interaction and interaction cross sections of card board are closer to virtual water than that of sun mica sheets. Conclusion: This study showed that card board could be used as tissue equivalent phantom for dosimetric studies in diagnostic x-ray energies and hence can be explored for the manufacturing of low cost phantom material with cardboard as the major raw material.