title: In vivo study of an x-ray fluorescence system to detect bone strontium non-invasively.
abstract: An x-ray fluorescence (XRF) system using 125I as the source was developed to measure strontium in bone in vivo. As part of an in vivo pilot study, 22 people were measured at two bone sites, namely the index finger and the tibial ankle joint. Ultrasound measurements were used to obtain the soft tissue thickness at each site, which was necessary to correct the signal for tissue attenuation. For all 22 people, the strontium peak was clearly distinguishable from the background, proving that the system is able to measure Sr in vivo in people having normal bone Sr levels. Monte Carlo simulations were carried out to test the feasibility and the limitations of using the coherently scattered peak at 35.5 keV as a means to normalize the signal to correct for the bone size and shape. These showed that the accuracy of the normalized Sr signal when comparing different people is about 12%. An interesting result arising from the study is that, in the measured population, significantly higher measurements of bone Sr concentration were observed in continental Asian people, suggesting the possibility of a dietary or race dependence of the bone Sr concentration or a different bone biology between races.
authors.affiliation: Medical Physics and Applied Radiation Science, McMaster University, Hamilton, L8S 4K1, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Zamburlini
authors.forename: A
authors.initials: A
authors.lastname: Pejović-Milić
authors.forename: D R
authors.initials: DR
authors.lastname: Chettle
authors.forename: C E
authors.initials: CE
authors.lastname: Webber
authors.forename: J
authors.initials: J
authors.lastname: Gyorffy
mesh_terms: D000328:Adult; D000368:Aged; D001842:Bone and Bones / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation* / Q000379:methods*; D013324:Strontium / Q000032:analysis*
chemical_list: D007457:Iodine Radioisotopes; D013324:Strontium