Data analysis
One radiologist performed sonoelastography measurements for all subjects. Two radiologists (S.S.E and A.K with 2 years of experience in elastography and 30 years of conventional US experience, respectively) determined the final interpretations through consensus. The radiologists were blind to the clinical information of the patients with MS (with or without optic neuritis).
Quantitatively analysis of optic nerve, optic disc, and perineural area stiffness was expressed as kPa with a color scale of 0-150 kPa and a region of interest at an interval of 2 to 3 mm. Three measurements for the quantitative value of each optic nerve, optic disc, and perineural area were acquired and the average values were used for the statistical analysis. (Fig1 and 2)