Radiothallium redistribution

As thallium has gained widespread clinical use, it is commonly employed to detect subtle zones of decreased perfusion in patients with minimal symptoms. Detection of lesions in patients with minimal zones of ischemia requires criteria other than transmural decrease in thallium concentration, since transmural myocardial perfusion abnormalities are rare. Now, lung uptake, changes in cavity size, or focal changes in the thickness of a wall have to be employed to detect myocardial ischemia. This paper illustrates findings in a patient with exertional chest pain. There is a focal decrease of perfusion seen in the apical inferior portion of the left ventricle, accompanied by lung uptake and a dilated left ventricular cavity. The delayed scans show substantial redistribution, reduction of cavity size, increase in wall thickness, and decrease of lung activity. Evidence for the lack of radiothallium redistribution is discussed