First-pass radionuclide angiography using a multiwire gamma camera and tantalum-178.

A portable multiwire gamma camera (MWGC) with enhanced imaging characteristics relative to conventional sodium iodide camera has been evaluated with 178Ta, a short-lived, generator-produced radioisotope (half-life 9.3 min). First-pass radionuclide angiography (FPRA) was performed and results were compared to those obtained with FPRA using a multicrystal camera (MCC) and 99mTc in 38 patients. The overall left ventricular count sensitivity (counts/mCi/sec/millisteradians [msr]) was significantly higher with MWGC/178Ta (176 +/- 132 versus 108 +/- 49, p less than 0.001) yielding images of higher statistics with higher resolution collimation (31 versus 63 msr). Left ventricular ejection fraction was 0.54 +/- 0.18 by MWGC and 0.54 +/- 0.18 by MCC with an excellent correlation between the two techniques (r = 0.94, s.e.e. = 0.06). The detection of wall motion abnormality was virtually identical with the two techniques. Intra- and interobserver reproducibility by MWGC was excellent (r = 0.99 and 0.99, respectively). Thus, this new technology provides first-pass studies of higher statistical quality and improved resolution, affording more precise assessment of left ventricular performance and likelihood of further substantial improvement by use of even higher doses of 178Ta.