A new technetium-99m labeled isonitrile complex 99mTc-TMCHI as a potential blood pool imaging agent.

Abstract A new isonitrile ligand 3,3,5-trimethyl cyclohexylisonitrile (TMCHI) and its copper salt [Cu(TMCHI) 4 BF 4 ] were synthesized and characterized by IR and elemental analysis. 99m Tc-TMCHI is prepared by direct labeling method with high RCP. In vitro protein binding in albumin, blood retention and biodistribution of 99m Tc-TMCHI in mice indicated that it is mainly accumulated and maintained in blood with a high protein binding rate and low washout rate. The target/non-target ratios in mice are excellent and suggest its use as a cardiac blood pool agent.