In vivo imaging of the spinal cord cholinergic system with PET.
OBJECTIVE
Our goal was to demonstrate the feasibility of an in vivo noninvasive method for imaging spinal cord cholinergic terminals using (+)-4-[18F]fluorobenzyltrozamicol ([18F]FBT) and PET.


METHODS
In vitro and in vivo experiments in rats were conducted to demonstrate the specific binding characteristics, localization, and time course of [3H]FBT binding in the spinal cord. PET imaging was then performed on seven rhesus monkeys.


RESULTS
The rat studies demonstrate high specific binding in the spinal cord with a distribution coinciding with the known distribution of cholinergic terminals. In vivo tracer concentrations in the spinal cord and basal ganglia were of the same magnitude. With use of [18F]FBT and PET in the rhesus monkey, the spinal cord was clearly visualized, with tracer concentration in the spinal cord being approximately one-fourth of that seen in the basal ganglia.


CONCLUSIONS
This work demonstrates the feasibility of imaging cholinergic terminals in vivo in the spinal cord using [18F]FBT and PET.
Division of Radiologic Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1061, USA.
H D
HD
Gage
J C
JC
Gage
A
A
Chiari
Z M
ZM
Xu
R H
RH
Mach
S M
SM
Efange
R L
RL
Ehrenkaufer
J C
JC
Eisenach
D000818:Animals; D001345:Autoradiography; D002799:Cholinergic Fibers / Q000000981:diagnostic imaging*; D005464:Fluorobenzenes; D066298:In Vitro Techniques; D008253:Macaca mulatta; D008297:Male; D009411:Nerve Endings / Q000000981:diagnostic imaging*; D010880:Piperidines; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000000981:diagnostic imaging*; D014055:Tomography, Emission-Computed
D005464:Fluorobenzenes; D010880:Piperidines; C087277:4-fluorobenzyltrozamicol