Autoradiography with 201Tl and our clinical experience

Thallium-201 has been suggested as a useful diagnostic agent for myocardial scanning. We report herewith the clinical usefulness of Tl-201 as a result of our animal studies with rats as well as clinical trial for human being. After intravenous injection, we killed rats at regular intervals, then measured the activity in each anatomized organ by γ-well counter and observed the internal distribution and examined autoradiograms with the naked eye. As a result, the accumulation of Tl-201 in the myocardium observed in 5 min after injection, reaching the maximum level in 30 min and gradually decreased hereafter. We performed 22 myocardial clinical scans. In adults we could clearly detect the lesion of myocardial infarction, but in children found it difficult to obtain fully sufficient information due to small heart size and high pulse rate. Judging from the foregoing we think it possible to obtain much clearer images by using a data analyzer. (auth.)