Contrast-enhanced orbital MRI for activity assessment and treatment response prediction in thyroid eye disease

To investigate the performance of contrast-enhanced orbital MRI (T1-weighted contrast-enhanced [T1CE] and dynamic contrast-enhanced MRI [DCE-MRI]) for activity assessment and prediction of treatment response to intravenous glucocorticoid (IVGC) treatment in thyroid eye disease (TED).

A retrospective study of 59 active moderate-to-severe TED patients (36 responsive and 23 unresponsive) treated with IVGC, matched with 31 inactive TED patients were included. T1CE and DCE-MRI were collected from each subject. Univariate and multivariate logistic regression analyses, as well as receiver operating characteristic (ROC) curves (evaluated by area under the curve, AUC) were used to evaluate the diagnostic and predictive models.

Active patients showed a higher signal intensity ratio of lateral rectus (LR-SIR) on T1CE and a higher wash-in rate of inferior rectus (IR-WIR) on DCE-MRI compared to inactive patients (p < 0.05). The AUC for T1CE and DCE-MRI based models were 0.866, and 0.844, respectively. The combined model (LR-SIR and IR-WIR) significantly enhanced model performance (AUC = 0.914, 95 % CI: 0.858-0.970). Responsive patients demonstrated a longer time to peak of lateral rectus (LR-TTP) than unresponsive patients (p < 0.05). The cutoff value of prediction probability was 0.678, and the AUC based on this model was 0.739 (95 % CI: 0.608-0.807).

T1CE and DCE-MRI could effectively assist in TED activity assessment, and DCE-MRI could help predict IVGC treatment response. Specifically, LR-SIR and IR-WIR were indicators of TED activity, and IR-TTP was predictive of IVGC treatment response. Combining both contrast-enhanced sequences could further enhance the efficiency of TED activity assessment.