Relative distribution of diphosphonate between bone and soft tissue at 4 and 24 hours: concise communication.
Digital bone scintigrams were obtained in 19 patients using Tc-99m hydroxyethylidene diphosphonate (HEDP). These were quantitated for skeletal, soft-tissue and renal uptake of tracer using a contrast-enhancement technique to define the regions of interest. Twenty-four hr whole-body retention (WBR) of HEDP was also measured. It was found that approximately 70% of retained diphosphonate was localized in the skeleton at 24 hr, with 26% in soft tissue and 4% in kidneys. However, we have shown that over a wide spectrum of whole-body retention measurements (18 to 70%) the 24-hr soft-tissue component, as a percentage of administered dose, remained relatively constant whereas skeletal tracer accumulation mirrored WBR (r = 0.98, p less than 0.001). The present study indicates that, despite a significant but essentially stable soft-tissue component, measurement of 24-hr WBR of HEDP accurately reflects skeletal metabolism.
D001842:Bone and Bones / Q000000981:diagnostic imaging*; D012968:Etidronic Acid; D006207:Half-Life; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging*; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D013667:Technetium; D013997:Time Factors; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; C019561:technetium Tc 99m etidronate; D013667:Technetium; D012968:Etidronic Acid