99mTc diphosphonate uptake mechanism on bone

Bone scanning or scintigraphy is directed towards identifying sites of altered skeletal metabolism and abnormal foci of calcium phosphate deposition, such as heterotopic ossification and soft tissue calcification. The requirements of an ideal bone-scanning agent are excellent imaging properties of the nuclide, high concentration of the nuclide at the abnormal site, little or no extraosseous of noncalcification site uptake, minimum tissue radiation, simple and safe preparation of the agent and ready availability of the nuclide. No scanning agent has all these ideal characteristics but the 99mTc diphosphonates come closest. 99mTc is easily obtained from a molybdenum-99/technetium-99m generator. The scheme, abundances, half-lives and energies are shown in this paper