The aim of this study was to evaluate the diagnostic efficacy of 18F-FDG PET/MRI in two different peripheral neuropathic pain models using the injured rat sciatic nerves. Twelve rats, with operation on left sciatic nerves, were evenly divided into three groups: sham surgery (control group), crushing injury and chronic constriction injury (CCI) (experimental groups). The nerve damage was assessed at 3 weeks postoperatively using following methods: paw withdrawal threshold values (RevWT), maximum standardized uptake values on PET/MRI images (SUVR), and counting the number of myelinated axons in proximal and distal sites of nerve injury (MAxR). The results were quantified and statistically analyzed. Compared to the control group, the crushing injury demonstrated significant differences in RevWT (p < 0.0001) and SUVR (p = 0.027) and the CCI group demonstrated significant differences in RevWT (p < 0.0001), SUVR (p = 0.001) and MAxR (p = 0.048). There were no significant differences between the two experimental groups for all assessments. Correlation analysis demonstrated that RevWT and SUVR assessments were highly correlated (r = -− 0.710, p = 0.010), and SUVR and MAxR were highly correlated (r = 0.611, p = 0.035). However, there was no significant correlation between RevWT and MAxR. The PET scan may be a valuable imaging modality to enable noninvasive, objective diagnosis of neuropathic pain caused by peripheral nerve injury. Also, MRI fused with PET may help clarify the anatomic location of soft tissue structures, including the peripheral nerves.
Bibliographical noteFunding Information:
The author thanks professor Jae Young Kim, in the Department of Oral and Maxillofacial Surgery at Gangnam Severance Dental Hospital, Yonsei University College of Dentistry, and Dr. Hye Yeong Lee, in the Department of Neurosurgery, Spine & Spinal Cord Institute, Yonsei University College of Medicine, for devoted supporting this study. This study was supported by the Yonsei University College of Dentistry (6-2-16-0019).
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All Science Journal Classification (ASJC) codes
- Cellular and Molecular Neuroscience