Multiparametric MRI quantitative metrics for grading and staging graves’ ophthalmopathy

OBJECTIVE: To explore the application of multiparametric magnetic resonance imaging (MRI) combined with clinical parameters in the assessment of Graves' ophthalmopathy (GO). METHODS: This retrospective study included 71 patients with GO (142 affected eyes) categorized into inactive (75) vs. active (67) and mild (70) vs. moderate-severe (72) subgroups. Clinical parameters were collected, and extraocular muscle (EOM) parameters [signal intensity ratio (SIR), T1 relaxation times (T1RT), T2 relaxation times (T2RT), and fat fraction (FF)] were measured (max/mean values). Predicted probabilities were derived from the generalized linear mixed model. Multivariate Logistic regression (based on the Akaike Information Criterion) was used to develop combined diagnostic models, and the marginal area under the receiver operating characteristic (ROC) curve (AUC) was employed to assess their efficacy. RESULTS: Compared with the inactive and mild groups, the active and moderate-severe GO eyes showed higher mean EOM-SIR, mean EOM-T1RT, and mean/max EOM-T2RT, as well as lower mean/max EOM-FF and female proportion (all P < 0.05). The active group had a shorter disease duration, whereas the moderate-severe group had higher thyrotropin receptor antibody (TRAb) levels (P < 0.05). For differentiating GO activity and severity, the combined staging Model 3 (EOM-FFmax + EOM-T1RTmean + EOM-T2RTmean + sex + thyroid functional status) and grading Model 6 (EOM-FFmax + EOM-T1RTmean + EOM-T2RTmean + sex + TRAb + thyroid functional status) yielded the best diagnostic efficacy, with AUCs of 0.912 and 0.947, respectively. CONCLUSION: The combined model of quantitative multiparametric MRI and clinical parameters enables a more accurate assessment of GO activity and severity.