Quantification of infarct size in the dog by thallium-201 single photon emission transaxial tomography (SPETT).

In a series of 12 dogs having an acute experimental anterior myocardial infarct, the size of the infarct was measured using, successively, single photon emission transaxial tomography (SPETT) with thallium-201, conventional planar scintigraphy of the anatomic slices, and planimetry of these slices after nitroblue-tetrazolium (NBT) staining. The tomographic views were obtained after processing of projection images collected during the rotation of a scintillation camera around the animals. A correlation of 0.86 was obtained between SPETT and NBT staining for the whole series, and a value of 0.94 was observed when only the transmural infarcts were considered. These results suggest that SPETT of the myocardium labelled with thallium-201 should allow a reliable, rapid and atraumatic estimation of the infarct size.