Correlation between joint [F-18] FDG PET uptake and synovial TNF-α concentration: A study with two rabbit models of acute inflammatory arthritis

The objective of this study was to verify that the [F-18]FDG PET synovial uptake is correlated with the synovial fluid (SF) TNF-α concentration. Two rabbit models of acute inflammatory arthritis induced by human interleukin-8 and lipopolysaccharide were used. Modified standard uptake values (MSUVs) obtained from PET images of the animals were compared with results of SF TNF-α measurements. Statistically significant correlations were found between the MSUVs and the SF TNF-α ratios. An equation to estimate the TNF-α ratio from a MSUV was also derived.