Myocardial 99m-Tc tetrofosmin reverse redistribution as a possible marker of tissue at risk

The reverse redistribution phenomenon (RR) refers to a myocardial perfusion defect that develops on rest imaging, whereas scans acquired after stress show an apparently uniform distribution. This finding has been observed with thallium-201 (Tl-201) in a variety of cardiac conditions. Tc-99m-labeled radio-pharmaceuticals may also yield a “reverse perfusion” pattern. As for thallium, some authors consider reverse perfusion of Tc-99m-labelled tracers a mere artifact, without clinical significance. Conversely, this phenomenon has been associated to coronary artery disease and myocardial infarction. We had also described that the reverse perfusion pattern with Tc-99m tetrofosmin could be often observed in patients with previous myocardial infarction and normal coronary arteries. We describe a sixty-year old patient with effort chest pain and reverse perfusion pattern at tetrofosmin Tc-99m SPECT who evidenced a significant stenosis on the proximal portion of the left anterior descendent coronary artery.