[Clinical and experimental investigations with 201tl for noninvasive myocardial scintigraphy (author's transl)].

The biological distribution of 201Tl after intravenous injection was studied experimentally in 42 rats. It was found (see figure 1) that the kidneys showed the greatest affinity for 201Th, reaching an activity concentration of 6.6% per gramme of tissue, almost independently of time. Within the first 30 minutes of injection, myocardial activity exceeds that of the surrounding structures (10 min. p.i.: 4.24%/g; 30 min. p.i.: 2.58%/g). During this time the myocardium can be well demonstrated by "image processing". The relatively fast myocardial kinetics of 201Tl (half value time 33 minutes) make it necessary, strictly speaking, to use a scintillation camera. The clinical value of this method is illustrated by a number of case histories.