Cardiac imaging with tantalum-178.

Tantalum-178 is a potential tracer for the first transit studies of the heart. It has a short physical half-life (9.3 minutes) and is obtained as a generator product from its long-lived (21.3 days) parent, tungsten-178. First transit studies were performed in the monkey and dog following the intravenous injection of 20 mCi (740 MBq) of tantalum-178. Imaging was performed with a large field of view single crystal camera and a multicrystal camera. Pulmonary dilution curves were derived for the analysis of left-to-right intracardiac shunting and high temporal resolution studies were obtained to assess left ventricular function and to measure left ventricular ejection fraction. The short physical half-life of tantalum-178 permits fraction. The short physical half-life of tantalum-178 permits multiple sequential studies with reduced patient radiation dose compared to the current radionuclide of choice, technetium-99m.