A multi-anode proportional counter for measuring (11C) carbon dioxide in exhaled air

Abstract

The aims of the authors were to develop a radiodetector for measuring the amount of (11C)carbon dioxide in exhaled air after intravenous injection of the radiotracer into the patient, and to use the detector as a complementary device in connection with positron emission tomographic studies of the distribution of the injected 11C-labelled compound and its metabolites. The results obtained show that a multi-anode gas proportional counter could be reliably used for measuring the amount of (11C)carbon dioxide in exhaled air. Despite the low total amount of (11C)carbon dioxide exhaled by the patient, the additional measured contribution to the radioactivity balance might be of importance, especially in the modelling of the metabolism and the transport of the injected compound.