Transcutaneous measurement of the arterial input function in positron emission tomography

To achieve reliable quantitation in positron emission tomography it is necessary to know the time course of activity concentration in the arterial blood during the measurement. The arterial blood curve from the brachial artery is compared to the activity measured in the internal carotid artery with a new transcutaneous detector. This system can be used as a complementary method for determining the circulation time through the brain. By measuring the period between maximum concentrations in the carotid and in the veins, a representative mean value is obtained for the circulation through the hemisphere