Coronary angiography with /sup 99m/Tc-pertechnetate

The flow of /sup 99m/Tc-pertechnetate injected into the left coronary arteries of 14 patients was studied by means of external monitoring. A quantitative estimate was made of the flow from 15 subunits of the left circumflex and the left anterior descending (LAD) arteries regions. Regional inflow and outflow were calculated from the time functions. The findings were compared with the results of coronary angiography performed previously. Statistical computations were made separately for 53 regions with normal coronary anatomy, 31 regions with stenosis of 5-25 %, 17 regions with stenosis of 26-50 %, 29 regions with stenosis of 51-75 % and 6 regions with a 76-100 % stenosis. The mean values revealed faster inflow and outflow rates in unstenosed regions and regions with lesser degree stenosis than in regions with stenosis exceeding 75 %. Significant differences were found between the regions with a 76-100 % stenosis and other regions studied. The diagnostic accuracy of the technique was demonstrated on a case with a normal angiogram and a case with proximal LAD conclusion. The pertechnetate method was found to be an accurate technique for measuring the regional coronary inflow and outflow rates. (author)