Lets go on a “Fantastic Voyage” Gene Expression Transmitter Synthesis Permeability Neurotransmission Reuptake Blood Flow Metabolism Receptor Binding
With PET we can image at the site of “thinking” Dopaminergic synapse (18)F-FBAU 18F-FDOPA 15O-[H2O] 11C-raclopride, etc 11C-CFT 15O-[H2O] 18F-FDG 11C-raclopride
What’s all this about models in PET? Dopaminergic synapse Plasma raclopride Free raclopride Bound raclopride ‘stuck’ raclopride
How can we tell which radioactivity comes from Free tracerBound tracerPlasma-borne tracer?
Tracer in each state has a unique temporal trajectory which is which ? tracer concentration What the PET scanner sees Bound Free Plasma Time (minutes)
(a) (b) P F B N (c) (d) The modeling process Imagine a living brain Consider the relevant neurochemistry Describe exchange between pools by a series of differential equations Abstract the neurochemistry into a series of connected pools Morris, E.D., C.J. Endres, K. Schmidt, B.T. Christian, R.F. Muzic, R.E. Fisher. Kinetic Modeling in PET. In Emission Tomography: The Fundamentals of PET and SPECT, ed. M. Wernick and N. Aarsvold. Academic Press. Amsterdam, Netherlands, 2004, pp. 499-540.
(a) (b) P F B N (c) (d) The modeling process