A neutral technetium-99m complex for myocardial imaging.

Technetium-99m-CDO-MeB [Bis[1,2-cyclohexanedione-dioximato(1-)- O]-[1,2-cyclohexanedione dioximato(2-)-O]methyl-borato(2-)- N,N',N'',N''',N'''',N''''')-chlorotechnetium) belongs to a family of compounds generally known as boronic acid adducts of technetium dioxime complexes (BATOs). It has an intrinsic affinity for the myocardium, with negligible lung activity and rapid blood clearance. The uptake of 3.44% ID in rat heart at 1 min postinjection for [99mTc]CDO-MeB versus 3.03% for 201TI indicates high extraction of [99mTc]CDO-MeB by the myocardium. In dogs an ischemic defect is clearly seen in SPECT images obtained 10 min after injection of [99mTc]CDO-MeB. Tissue distribution data in rats show that [99mTc]CDO-MeB is excreted primarily in the feces and to a lesser extent in the urine. Approximately 80% of the activity is excreted within 24 hr after injection.