Verification of rubidium-82 for heart studies

Whereas 82Rb has been shown to reflect heart blood-flow under normal circumstances and has the great benefit of being available from a noncyclotron source, there remains a question with regard to the physiology of rubidium transport into the heart muscle. The fraction of the amount of the rubidium tracer that goes into the heart varies with flow, and, unfortunately, the amount that accumulates in the muscle will not therefore be proportional to flow. Over the past three years, the authors have re-evaluated this question and determined that the uptake of rubidium in the myocardium follows a simple model of conservation of mass wherein the amount that is present is equal to the product of flow times extraction