[Isotope angiographic measurement of blood flow velocity in the human aorta and major arteries. I. Methodology and physiological considerations].

A special 8-channel detector arrangement was used to determine atraumatically the mean blood flow velocities in the aorta and the large arteries of the lower extremities in man. Following intravenous injection of 99mTc-pertechnetate time-activity curves were recorded over defined measuring points over the arteries, from these the appearance times of the tracer determined, and the mean blood flow velocities calculated from the differences between appearance times (the minimal transit times) and the distances between measuring points. The simultaneous determination of the minimal transit times between the vena cava inferior and the root of the aorta, which correspond closely to the total cardiac transit times, permits recognition of cases in whom blood flow velocity is reduced as a result of cardiac disease.