Multiple-radionuclide autoradiography in evaluation of cerebral function.

We have developed the mathematical model and experimental technique for quantitative simultaneous multiple-radionuclide autoradiography. The technique is an extension of previously described dual-tracer methods and offers the advantage of a general approach in which any two or more radionuclides with different half-lives can be used to measure multiple parameters of cerebral function. The model allows the selection of nuclide doses and exposure times to balance cross-contamination of the multiple images with nuclide requirements. The technique was validated with homogeneous tissue sections containing combinations of 123I, 124I , 131I, 18F, 99mTc , 68Ga, and 14C, and then used in qualitative and quantitative investigations of interrelationships of local cerebral blood flow, glucose metabolism, and protein synthesis in normal and several pathological conditions in rats.