PET imaging of the opioid receptor: the early years

Advances in the technetium chemistry have significantly enhanced the development of Tc-99m radiopharmaceuticals for clinical use. Efforts in designing novel Tc-99m labeled receptor or site-specific imaging agents using [TcvO]+3N2S2 core have produced useful imaging agents for single photo emission computed tomography (SPECT). The success in developing Tc-99m TRODAT-1 for CNS dopamine transporters (DAT) serves as the first example of Tc-99m site-specific imaging of human brain. New innovative Tc-99m labeled site-specific agents are particularly suitable to develop simple and useful routine diagnostic procedures.