Multiparametric magnetic resonance imaging in determining disease activity of thyroid-associated ophthalmopathy: Added value from DCE and DWI

Motivation: Accurately assessing thyroid-associated ophthalmopathy (TAO) activity is essential for clinicians to develop an appropriate therapeutic plan. Goal(s): Evaluate the performance of DCE-MRI and DWI in determining TAO activity and to establish their additional value for staging TAO compared to conventional T2WI. Approach: Simplified histogram parameters of Ktrans, Kep, Ve, ADC and SIR at extraocular muscles were calculated for each orbit and compared between the active and inactive groups Results: The mean Ve, mean ADC and mean SIR were found to be independent predictors for active TAO. Combination of mean Ve, mean ADC and mean SIR outperformed mean SIR alone in staging TAO. Impact: DCE-MRI, which provides information on microcirculatory perfusion and permeability, and DWI, which evaluates water diffusion properties of EOMs in different stages of TAO. Therefore, DCE-MRI and DWI may serve as reliable supplementary techniques to the conventional T2WI in staging TAO.