A method for measurement of arterial concentration of cerebral blood flow tracer for autoradiographic experiments.

A new method for continuous monitoring of the concentration of 131I-labelled iodoantipyrine during an autoradiographic local cerebral blood flow (LCBF) experiment is described. During infusion of iodoantipyrine, radioactivity in an external femoral arteriovenous loop is monitored by a scintillation detector. Data is collected with a variable time base, and the arterial activity curve displayed visually in its entirety. The main advantage of this method is that there is no blood loss. It will therefore be of particular importance in dual-label autoradiography. This method can also be used for other gamma-emitting blood flow tracers, e.g. 123I-iodoantipyrine.