Abstract
We demonstrated increased 18F-FDG uptake in injured peripheral nerves in a model of neuropathic pain using small-animal PET/MRI. Methods: A neuropathic pain model in rats was created by spared-nerve injury of the left sciatic nerve. Sham-operated rats without nerve injury were used as a control. The presence of pain was confirmed by testing for allodynia. Sequential small-animal 18F-FDG PET and MRI scans of the thighs were obtained and coregistered. Autoradiography was performed on harvested nerves and muscle. Results: The group with spared-nerve injury showed the development of allodynia in the operated limb (P < 0.001). Increased 18F-FDG uptake was observed on both PET/MRI (P < 0.001) and autoradiography (P < 0.005) in the operated nerve in this group. 18F-FDG uptake in the nerves correlated well with allodynia (ρ = −0.59; P < 0.024). Conclusion: Animals with neuropathic pain show increased 18F-FDG uptake in the affected nerve. Small-animal PET/MRI can be effectively used to localize 18F-FDG uptake in peripheral nerves.
- © 2011 by Society of Nuclear Medicine