system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Bone and Bones, Diphosphonates, Femur, Fractures, Bone, Male, Organotechnetium Compounds, Radionuclide Imaging, Radiopharmaceuticals, Rats, Rats, Wistar, Technetium Tc 99m Medronate, Time Factors.
user
Is (99m)Tc-labelled pamidronate a better agent than (99m)Tc-medronate for bone imaging? Context: To evaluate the potential of (99m)Tc-pamidronate ((99m)Tc-APD) against (99m)Tc-medronate ((99m)Tc-MDP) as a new bone-seeking agent using intact bone and fractured femur in a rat model. (99m)Tc-APD was prepared by the stannous reduction method. Scintigraphic images were obtained at 2 h and 24 h after intravenous injection of (99m)Tc-APD or (99m)Tc-MDP in rats, then they were culled to estimate activities in various organs. Bone uptake (as percent injected dose/gram weight) was estimated in an intact femur and in 1 week post-fracture model. The urinary excretion dose (as percent injected dose) was also estimated. The bone uptake of (99m)Tc-APD was significantly higher (P<0.05) than (99m)Tc-MDP at 2 h and 24 h post-injection studies. (99m)Tc-APD uptake was further increased (P<0.05) in the fracture model than the intact femur. (99m)Tc-APD uptake in the soft tissues including liver and the kidneys was lower than (99m)Tc-MDP. Renal excretion was faster and the ratios of bone to blood and bone to soft tissues were higher with APD than MDP. APD dose was selected at 1% of MDP, to obviate therapeutic effect, as the former compound is 100 times more potent than MDP.
assistant
Our results suggest that (99m)Tc-APD uptake by intact bone and fractured bone was significantly higher than (99m)Tc-MDP. The renal clearance of (99m)Tc-APD was faster and soft tissue uptake was lower than (99m)Tc-MDP. These results suggest that APD has the potential to become an excellent bone-imaging agent.