1. Brain… The Final Frontier…

2. Lets go on a “Fantastic Voyage” Blood Flow Metabolism Permeability Receptor Binding Gene Expression Neurotransmission Transmitter Synthesis Reuptake

3. With PET we can image at the site of “thinking” 15O- [H2O] 18F-FDG 15O-[H 2 O] 11C- raclopride (18)F- FBAU 11C-raclopride, etc 18F- FDOPA 11C-CFT Dopaminergic synapse

4. OK. So what’s the problem?

5. What’s all this about models in PET? Bound raclopride Free raclopride Plasma raclopride ‘stuck’ raclopride Dopaminergic synapse

6. How can we tell which radioactivity comes from Free tracer Bound tracer Plasma-borne tracer ?

7. Tracer in each state has a unique temporal trajectory Time (minutes) tracer concentration Plasma Free Bound What the PET scanner sees which is which ?

8. Divining the shape of each curve depends on kinetic modeling of the data.

9. The modeling process (b) PFB N (c) (d) (a) Imagine a living brain Consider the relevant neurochemistry Abstract the neurochemistry into a series of connected pools Describe exchange between pools by a series of differential equations 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.

10. The modeling process (b) PFB N (c) (d) (a)

11. The Modeling Process PFB N (a)(b) (c)(d) Return