Scintigraphic quantification of myocardial necrosis using "hot spot" imaging agents in acute myocardial infarction]

Both technetium-99m pyrophosphate/thallium-201 dual nuclide SPECT and indium-111 antimyosin antibody/thallium-201 dual nuclide SPECT were performed in identical 11 patients with acute myocardial infarction. Infarct size was calculated by both hot spot imaging agents on dual nuclide SPECT. Antimyosin accurately accumulated in the infarcted area in all 11 patients on SPECT images corresponding with the electrocardiography, but pyrophosphate accumulated at the site of infarct in 10 of 11 patients. The mean volume obtained from pyrophosphate was 32.5 ml and that from antimyosin was 21.9 ml. The relationship between infarct volume calculated by pyrophosphate and that by antimyosin was linear and correlated well (r = 0.98, p less than 0.001). However the volume of infarction determined with pyrophosphate exceeded that with antimyosin SPECT by 1.64 (p less than 0.001). The reason for this difference is not yet known, but may relate to pyrophosphate uptake in border zones that may or may not be irreversibly injured.