Assessment of surrogate structures for whole body counting

Evaluation of internally-deposited, photon-emitting radionuclides by external in vivo scintillation measurements requires a method to calibrate the radiation detectors in order to convert counts measured by the detection system into an amount of activity deposited in the organ or tissue of interest. The most practical calibration techniques for in vivo measurement procedures involve construction and measurement of human surrogate structures in which known amounts of activity are inserted in artificial tissues and/or organs to simulate the expected distribution. In this paper, in vivo measurements with the NYU Am-241 skull phantoms and the skull from a skeleton with an incorporated Am-241 burden, derived from accidental inhalation exposure, demonstrates the validity of well-designed surrogate structures as a primary calibration mechanism