Measurement of regional perfusion of the myocard by recording the distribution of Rb81-Kr81 with a SPECT-system

The activity ratio of 81Rb and its short living daughter product sup(81m)Kr meet the requirements for the direct measurement of the perfusion of organs. Because of the short half life of sup(81m)Kr the deviation from radioactive equilibrium is only 25% at a perfusion rate of 100 ml/min x 100 g. We used a SPECT-system with simultanous recording in the two energy windows of 81Rb and sup(81m)Kr. As the tomogramms are without superposition of other tissues the possibilities of the 81Rb-sup(81m)Kr can be fully utilized. In the examination of 106 patients we have found that with the Rb-Kr-tomograms, recorded at rest, we are able to differentiate between sites of infarction and regions of ischemia. All examinations have been compaired with coronary angiography and a part of them also with 201Tl scintigraphy. The method can also be used for objectivation of coronar dilatation and bypass-surgery. (Author)