Opfer R, et al. - Authors examined the relapsing multiple sclerosis (MS) patients with MRI follow-ups in order to determine whether after 1-year pathological brain volume loss (BVL) was detectable in a relevant fraction of MS patients, with the aid of SIENA/FSL. Data reported that the estimated standard deviation of BVL measurements from the pooled reliability datasets was 0.28%. In the MS patient cohort, the median BVL per year was found to be 0.44%. In 18% of the subjects, a BVL per year equal or greater than 0.94% was discovered. Yielded findings displayed that within-patient fluctuation (WPF) could be beneficial while interpreting BVL results on an individual patient level in diseases such as MS.