C. Reiners et al., X-ray fluorescence analysis (XFA) of thyroidal iodine content (TIC) with an improved measuring system, EXP CL E D, 106, 1998, pp. S31-S33
Citations number
34
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
EXPERIMENTAL AND CLINICAL ENDOCRINOLOGY & DIABETES
X-ray fluorescence analysis is based on the principal that the electron str
ucture of stable iodine in the thyroid is excited by Americium-241 gamma ra
ys to emit a characteristic fluorescence radiation which is proportional to
the amount of iodine present in the gland. A stationary measuring system c
onsisting of a 11.1 GBq Am-241 source and a high-purity Germanium detector
with spectrum analyser has been improved by a PC guided method for sonograp
hic definition of the measuring volume. The lower limit of detectibility of
the system corresponds to 0.01 mg of Iodine per mi of thyroid volume; the
in vivo precision given as coefficient of variation amounts to 15%. The thy
roid is exposed with a radiation dose of 6 mu Sv per measurement. First stu
dies with this improved system carried out in 50 female volunteers between
20 and 40 years of age with normal thyroid volumes resulted in a mean iodin
e concentration of the thyroid of 0.665 +/- 0.304 mg/ml. The mean iodine ex
cretion in urine was normal with 10.8 +/- 10.4 mu g/dl.