Technetium-99m
Technetium-99m (99mTc) pertechnetate is a radioisotope that may be attached to various substrates for use in bone scanning. It may be used to label polyphosphate (rarely used today), diphosphonate 1).
Technetium-99m is a metastable nuclear isomer of technetium-99 (itself an isotope of technetium), symbolized as 99mTc, that is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical radioisotope.
1)
Handa J, Yamamoto I, Morita R, et al. 99mTc-
Polyphosphate and 99mTc-Diphosphonate Bone
Scintigraphy in Neurosurgical Practice. Surg Neurol.
1974; 2:307–310