The study assessed group differences in the thalamus microstructural parameters among healthy individuals and relapsing-remitting multiple sclerosis (RRMS) patients and examined the relationship between quantitative MRI (qMRI) parameters and neurological scores, T2 lesion load, and serum neurofilament light chain (sNfL) levels.A total of 30 patients with RRMS and 26 age- and sex-matched healthy controls were recruited in this study. The qMRI images were obtained from these individuals. T2 lesion load, thalamic volume, and parameters of thalamic subnuclei were estimated. The neurological functions of participants were assessed using a battery of tests. sNfL concentrations were measured using the single molecule array (SIMOA) technique.T2 relaxometry in the whole thalamus and its subnuclei were increased, and showed an apparent correlation with T2 lesion load and the severity of MS (EDSS, MSSS, 9HPT, T25FW, SDMT). T1 variability was prolonged in most thalamic subnuclei, and it was correlated with the severity of MS (EDSS, 9HPT, SDMT). Thalamic volumetric parameters of MS patients were smaller than those of healthy controls (p < 0.001) and showed an apparent correlation with MS severity. Surprisingly, sNfL levels showed no correlation with T2 relaxometry, T1 variability, or thalamic volumetric parameters.Quantitative synthetic MRI, especially, the metric T2 relaxation times provides a surrogate parameter for assessing underlying thalamic and subnuclei damage in the RRMS group. Integrating structural and quantitative MRI allows a better assessment of the neurodegeneration in the normal-appearing thalamus of RRMS.Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.