<prompt> In radionuclide imaging, the most useful radiopharmaceutical agent for skeletal imaging is: March 2012Tc-99m linked to methylene diphosphonate 99m Tc-MDPTc-99 pyrophosphateTc-sulphur colloid 99m Tc-ScGallium 67  <response>: Ans: A i.e. Tc-99m linked to methylene diphosphonate 99m Tc-MDP Radiopharmacological agents and uses Tc-99m linked to methylene diphosphonate 99m Tc-MDP is used in bone imaging Tc-99 pyrophosphate is used for defining hot spots in myocardial infarctionavid infarct imaging 99m Tc-Sc is used in imaging of reticuloendothelial system liver spleen, gastric emptying, GI bleeds Gallium 67 is used for tumoursabscess 