Evaluation of [18F]-4-Fluoroantipyrine as a New Blood Flow Tracer for Multiradionuclide Autoradiography

Abstract

This article reports the evaluation of [¹⁸F]-4-fluoroantipyrine (FAP) as a quantitative blood flow tracer by comparing blood flow measured with [¹⁸F]FAP to that determined simultaneously with [¹⁴C]-4-iodoantipyrine (IAP), a standard blood flow tracer, by means of double-tracer autoradiography. The single-pass extraction value ( m), which indicates diffusibility of a tracer, was determined according to the procedure described by Crone. The diffusibility of FAP was essentially the same as that of IAP. The brain–blood partition coefficient for FAP was found to be similar to that for IAP, 0.89 ± 0.01. Values of local cerebral blood flow obtained with FAP agree with those determined with IAP. From these results, we concluded that FAP is indeed as good a blood flow tracer as IAP. Since ¹⁸F is a positron-emitting radionuclide, it might be a useful tracer for blood flow measurement by positron emission tomography.