PURPOSE: This study evaluates the value of [ METHODS: Twenty-three TED patients and ten healthy controls were prospectively recruited and underwent [ RESULTS: Eye-based analysis included 42 TED eyes and 20 control eyes. SUVmax did not differ significantly between CAS-/FAPI + (n = 8) and CAS + /FAPI + (n = 17) eyes
though both groups had significantly higher SUVmax than CAS-/FAPI- (n = 16), CAS + /FAPI- (n = 1), and control eyes (n = 20) (all P <
.05). Diffuse high FAPI uptake with excellent TBR was observed in pathologically active EOMs and had higher SUVmax and TBR than inactive EOMs (SUVmax: 9.57 ± 2.79 vs. 4.04 ± 1.02, TBR: 2.99 ± 1.00 vs. 1.00 ± 0.35, both P <
.001). An SUVmax cutoff value of 5.95 yielded an area under the receiver operating characteristic curve of 0.98 for predicting active disease. Sensitivity and specificity of CAS-driven and FAPI-driven assessments for TED activity were 72.7% and 100%, 100% and 100%, respectively. SUVmax positively correlated with pathological fibroinflammatory score (r = 0.68, P = .004). CONCLUSION: The diffuse high FAPI uptake with excellent TBR in the EOMs could illustrate the activity of TED, positively correlated with pathological fibroinflammatory scores. These findings suggest that [