Tc-99m tertiary butyl isonitrile : a preliminary clinical study of a new myocardial imaging agent in patients with chest pain

Tc-99m is a preferred agent for nuclear imaging. Tc-99m tertiary butyl isonitrile (Tc-99m-TBI) is the first of a family of lipophilic cations which allow effective imaging of the human myocardium. Twenty-one patients scheduled for coronary angiography for the investigation of their chest pain were studied after injections of this tracer given during exercise, and on a separate visit, at rest. Despite high uptake in the liver and transiently in the lungs, high quality gated images were obtained allowing the assessment of both myocardial uptake and wall motion. The findings corresponded closely with angiographic and ventriculographic assessment of coronary artery disease and myocardial infarction. Redistribution of Tc-99m-TBI was shown to occur in ischemic myocardium analogous to that occurring with thallium-201 (Tl-201). Similar agents with more favourable properties may well replace Tl-201 as the myocardial imaging agent of choice in the near future