Technetium TC 99M Pyrophosphate is a radionuclide imaging agent used primarily in scintigraphy or tomography of the heart to evaluate the extent of the necrotic myocardial process. It has also been used in noninvasive tests for the distribution of organ involvement in different types of amyloidosis and for the evaluation of muscle necrosis in the extremities. It is also used to demonstrate areas of altered osteogenesis. May also be used to image gated blood pools and detect gastrointetinal bleeding.