Organ and tissue equivalent doses from abdominal x-ray examinations calculated with the MAX/EGS4 exposure model

Full text: The incident air kerma (INAK), the entrance surface air kerma (ESAK), and the dose-area product (DAP) are considered relevant measurable quantities, suitable to be used for the evaluation of exposure to the patient in x-ray diagnosis. The recently developed MAX (Male Adult voXel) phantom connected to the EGS4 Monte Carlo code was used to calculate conversion coefficients between average equivalent dose to organs and tissues at risk and the measurable quantities INAK, ESAK, and DAP, respectively, for a variety of commonly performed x-ray examinations. This investigation presents conversion coefficients between organ and tissue equivalent dose and ESAK for abdominal x-ray examinations for the MAX phantom, which will be compared with corresponding results for mathematical MIRD5-type phantoms published by others. The comparison shows agreement and disagreement between the data for the two exposure models, which clearly reflect the anatomical differences with respect to shape and position of the organs at risk. (orig.)