Evaluation of /sup 99m/Tc stannous pyrophosphate as an imaging agent in acute myocardial infarction

Serial /sup 99m/Tc pyrophosphate scintigrams were obtained 7 hr to 15 days after experimental acute myocardial infarction produced by permanent or transient coronary occlusion. Scintigrams were interpreted visually and the increased radioactivity in the precordial image was quantitated and compared to extent of infarction found histologically. Results of these studies indicate: (1) /sup 99m/Tc pyrophosphate imaging is an extremely sensitive technique for detection of acute myocardial infarction, i.e., infarction in excess of 1% of the left ventricular mass was detected. (2) Early detection of acute infarction is a function of blood flow since 7 hr after infarction, scans were negative after permanent occlusion but were strongly positive after transient occlusion. (3) Radioactivity in the precordial image was inversely related to extent of infarction after transient occlusion. (4) /sup 99m/Tc pyrophosphate localized in areas with significant histologic infarction but the distribution of radioactivity was not proportional to extent of infarction.