The in situ measurement of strontium content in bone using X-ray fluorescence analysis

Abstract

A technique is described which uses x-ray fluorescence to determine in situ the strontium content of bone. Measurements were made of the skulls of seven rabbits both before and after a single bolus injection of strontium was administered intravenously. The retention of strontium was followed for up to eight months and could be represented either by a three-exponential model or, for data obtained between 12 and 252 d following injection, the power function At-b, where t is the time in days following injection. The three-exponential terms had linear coefficients of similar magnitude and half lives of 3-4 h, 10-40 d and 200-300 d. The exponent of the power function was 0.25-0.57. Measurements were also made of the skull and medial surface of the tibial crest of an adult dog for four months following subcutaneous administration of strontium. The results obtained using x-ray fluorescence are found to be similar to those reported by others for radiostrontium studies. The precision and errors associated with the fluorescence technique are discussed. Estimates of radiation dose are given. It is concluded that the technique may serve to determine in situ the strontium content of bone near the surface of the body.

Application of XRF to Measure Strontium in Human Bone In Vivo

“…In vivo, the overlying tissue thickness can be determined ultrasonically with an accuracy of 0.3 mm with the use of a 7 MHz ultrasound transducer (12). Alternatively ; the measured signal can be normalized with respect to coherently and incoherently scattered radiation (13). An improved response to the Sr signal can be attained by using polarized radiation to excite the Sr characteristic radiation (12) .…”

Second generation of the diagnostic tool for the In vivo measurement of strontium levels in human bone

“…As for Sr, four bone Sr IVXRF systems have been reported to date. Snyder and Secord (1982) modeled Sr retention in the skull of seven rabbits after the administration of Sr intravenously. Using Cd-109 as the excitation source and a 80mm 2 X 5mm 2 Kevex Si(Li) detector as the detection system, they obtained the biological half-lives for radioactive strontium.…”

In vivo applications of X-ray fluorescence in human subjects

“…Snyder and Secord measured bone strontium in rabbits [43] and, in a totally separate development, Wielopolski and his colleagues demonstrated that they were able to measure bone strontium in human subjects [44]. However, neither of these initiatives were followed up in the respective laboratories.…”