Evaluation of [18F]-4-fluoroantipyrine as a new blood flow tracer for multiradionuclide autoradiography.

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.