The production of body analogs for use in radiation physics

Bone, muscle and lung analog materials have been produced in-house, and dosimetry phantoms have been produced. A method using computed tomography (CT) has been developed to check that the analogs produced match the radiation properties of body tissues. The relative electron densities and ratio of electron cross sections are calculated from elemental compositions of the analogs. Using these data the theoretical CT numbers are calculated and these numbers are compared with experimental CT numbers for the analogs produced. The experimental CT numbers are found by scanning the samples on a Siemens DRH CT scanner. Results show the maximum difference between theoretical and experimental CT numbers for the analogs is 18 Hounsfield units, which relates to a delta NCT of less than 1%. Comparison of analog CT numbers with CT numbers for the related patient tissues also shows a close match.