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Dose calibrator manufacturer-dependent bias in assays of 123I



Denis E. Bergeron, Jeffrey T. Cessna, Daniel B. Golas, Rheannan K. Young, Brian E. Zimmerman


Calibration factors for commercial ionization chambers (i.e. dose calibrators) were determined for a solution of 123I; the activity was based on the 1976 NBS standard. A link between the NIST standard and the International Reference System (SIR) was established. The two major U.S. dose calibrator manufacturers recommend oppositely biased calibration factors, giving a spread of 11.3 % in measured activities. With modern quantitative imaging techniques capable of ≤ 10 % accuracy, this bias for a SPECT nuclide is highly significant.
Applied Radiation and Isotopes


Ionization chamber, dose calibrator, I-123, secondary standard, quantitative imaging


Bergeron, D. , Cessna, J. , Golas, D. , Young, R. and Zimmerman, B. (2014), Dose calibrator manufacturer-dependent bias in assays of 123I, Applied Radiation and Isotopes, [online], (Accessed July 14, 2024)


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Created March 25, 2014, Updated October 12, 2021