Association Between Intermittent Fasting and Susceptibility‐Weighted MRI Phase Values in Deep Gray Matter of Patients With Multiple Sclerosis: An Observational Cohort Study

BACKGROUND: One manifestation of multiple sclerosis (MS) is abnormal iron-related susceptibility changes in deep gray matter (DGM), contributing to oxidative stress and neurodegeneration. Intermittent fasting (IF) is a metabolic intervention that may influence inflammatory and iron-related pathways. PURPOSE: To compare susceptibility-derived phase values in DGM between fasting and non-fasting periods in patients with MS. STUDY TYPE: Retrospective observational cohort study. POPULATION: 36 patients with MS were studied: a fasting group (n = 20; mean age 33.1 ± 9.6 years; 14 males), a non-fasting control group (n = 14; mean age 34.9 ± 10.8 years; 10 males), and two cases with additional measurements. FIELD STRENGTH/SEQUENCE: 1.5 T; Echo Planar Susceptibility-Weighted Imaging (EPI-SWI). ASSESSMENT: Paramagnetic mean phase values (pMPVs) were measured in nine bilateral DGM regions at 2 time points separated by a 1-year interval. STATISTICAL TESTS: Paired and independent t-tests were used to analyze phase value changes; a p-value of less than 0.05 was considered statistically significant. RESULTS: Inter-rater reliability was high (ICC = 0.91). The fasting group had lower pMPVs at the second time compared to the first (48.91 ± 10.45 vs. 38.38 ± 11.23; mean difference -10.53; 95% CI: -13.28 to -7.78), with consistent reductions across all subregions. The non-fasting group showed the opposite pattern (45.42 ± 19.98 vs. 52.99 ± 21.05; 95% CI: 4.71 to 10.43), while bilateral thalamic values remained stable (left p = 0.104; right p = 0.938). Serial case studies are associated with temporal patterns in pMPVs during fasting and non-fasting intervals. DATA CONCLUSION: Measurements during fasting periods were associated with lower pMPVs in DGM in multiple sclerosis compared to non-fasting periods. TECHNICAL EFFICACY: Stage 3.