Metabolic and Inflammatory Determinants of Spinal Cord Physiological Activity Evaluated by 18F-FDG PET/CT

Introduction: 18F-fluorodeoxyglucose (FDG) PET/CT has a well-established role in evaluating malignancies, particularly those with metastases to the brain. However, less is understood about the physiological FDG uptake patterns in the spinal cord, a common site for metastases, inflammation, and degenerative disease. Identifying the determinants of physiological FDG uptake is essential for accurate diagnostic workup of oncological patients as well as for understanding the metabolic and inflammatory changes associated with spinal pathology. In this study, we assessed spinal cord physiological activity using FDG PET/CT imaging and explored its relationship to metabolic and inflammatory biomarkers, with implications for early detection of spinal cord pathology.

Methods: 89 control volunteers (42 females, 47 males) mean age 44.5 (SD 13.9) years were selected from the Cardiovascular Molecular Calcification Assessed by 18F-NaF PET/CT (CAMONA) clinical trial (NCT01724749). Artificial intelligence (AI)-based quantification was used to determine the mean standardized uptake value (SUVmean) for FDG uptake in the spinal cord. Linear regression was applied to assess correlations between spinal cord radiotracer uptake and clinical factors, including body mass index (BMI), age, gender, and metabolic/inflammatory biomarkers.

Results: FDG uptake in the spinal cord correlated with patient BMI (p < 0.001), though no significant associations were found with age or gender. Elevated FDG retention was also associated with increased levels of C-reactive protein (p = 0.046), white blood cell count (p = 0.001), fibrinogen (p = 0.048), homocysteine (p = 0.008), and hemoglobin A1c (HbA1c) (p = 0.034). No correlations were observed between FDG uptake and either smoking history or alcohol consumption (p > 0.05).

Conclusion : 18F-FDG PET/CT imaging of the spinal cord provides insight into the pathophysiological mechanisms of spinal degeneration and inflammation. The delineation of physiological and pathological patterns of FDG uptake may inform early, non-invasive diagnostic strategies and guide appropriate treatment planning for patients with spinal disease.