Biological variation in cervical spinal cord MRI morphometry in healthy individuals and people with multiple sclerosis

Abstract Background and Purpose Conclusions from prior literature regarding the impact of sex, age, and height on spinal cord (SC) MRI morphometrics are conflicting, while the effect of body weight on SC morphometrics has been found to be nonsignificant. The purpose of this case‐control study is to assess the associations between cervical SC MRI morphometric parameters and age, sex, height, and weight to establish their potential role as confounding variables in a clinical study of people with multiple sclerosis (MS) compared to a cohort of healthy volunteers. Methods Sixty‐nine healthy volunteers and 31 people with MS underwent cervical SC MRI at 3 Tesla field strength. Images were centered at the C3/C4 intervertebral disc and processed using Spinal Cord Toolbox v.4.0.2. Mixed‐effects linear regression models were used to evaluate the effects of biological variables and disease status on morphometric parameters. Results Sex, age, and height had significant effects on cord and gray matter (GM) cross‐sectional area (CSA) as well as the GM:cord CSA ratio. There were no significant effects of body weight on morphometric parameters. The effect of MS disease duration on cord CSA in the C4 level was significant when controlling for all other variables. Conclusions Studies of disease‐related changes in SC morphometry should control for sex, age, and height to account for physiological variation.