Histogram of Apparent Diffusion Coefficient to Evaluate the Activity of Thyroid‐Associated Ophthalmopathy

Abstract

ABSTRACT Objective This study aimed to evaluate the activity of extraocular muscles (EOMs) in patients with thyroid‐associated ophthalmopathy (TAO) using turbo spin echo imaging. By analyzing tissue heterogeneity, apparent diffusion coefficient (ADC) histogram analysis offers enhanced insights into edema within the EOMs. Methods Eighty‐eight patients with TAO were retrospectively evaluated and allocated into active (n = 24, clinical activity score [CAS] ≥ 3) and inactive (n = 64, CAS 1.26 μm2/s, entropy > 4.03, and standard deviation (SD) > 0.4 of the ADC histogram, were significant predictors of TAO activity, with odds ratios of 2.741 and 6.806, 5.070, 2.652, and 2.197, respectively (all p 1.26 μm²/s, entropy > 4.03, or SD > 0.4 may also predict active TAO.

Keywords

• apparent diffusion coefficient
• clinical activity score
• extraocular muscle
• intravoxel incoherent motion
• thyroid‐associated ophthalmopathy
• turbo spin echo