title: Simulation of measurements of uptake of 123I-iodide in the thyroid of fetal chimpanzees.
abstract: The quantitative assessment of the uptake of 123I-iodide (123I-) in the fetal thyroid in vivo was simulated in phantom measurements. First, the relationship between the depth of the fetal thyroid phantom and the two-peak ratio, the ratio of the counts in the gamma-ray and the X-ray energy windows of the registered spectrum, was determined. Subsequently, the attenuation of the gamma-ray signal in relationship to the depth of the fetal thyroid phantom was determined. Finally, the relationship between the two-peak ratio and the attenuation of the gamma-ray signal was deduced. For a reliable correlation, the signal recorded from the radioactivity surrounding the fetal thyroid phantom has to be subtracted from that obtained with the fetal thyroid phantom present. A correction curve was generated to be applied to the in vivo measurements. It is concluded that with this method determination of uptake of 123I- in the fetal thyroid is feasible.
authors.affiliation: Comprehensive Cancer Center, Rotterdam, The Netherlands.
authors.forename: J L
authors.initials: JL
authors.lastname: Noteboom
authors.forename: W A
authors.initials: WA
authors.lastname: Hummel
authors.forename: J T
authors.initials: JT
authors.lastname: Jansen
authors.forename: D W
authors.initials: DW
authors.lastname: van Bekkum
authors.forename: J J
authors.initials: JJ
authors.lastname: Broerse
mesh_terms: D000818:Animals; D005333:Fetus / Q000378:metabolism*; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics*; D009010:Monte Carlo Method; D002679:Pan troglodytes; D013961:Thyroid Gland / Q000378:metabolism*
chemical_list: D007457:Iodine Radioisotopes