Quantitative susceptibility mapping demonstrates aging-related long-term structural brain changes in adult rats after mild ischemic stroke

Abstract Quantitative susceptibility mapping is a novel, non-invasive MRI technique that measures tissue magnetic susceptibility, offering insights into brain iron, calcium, and myelin distribution. Here, we used quantitative susceptibility mapping to assess whole-brain long-term susceptibility changes in adult rats following endothelin-1-induced mild focal stroke in the right motor cortex over 48 weeks. No significant differences in susceptibility trajectories were found between stroke and sham groups in either hemisphere. However, both groups exhibited shared regional susceptibility changes, likely age-related, reflecting variations in iron, calcium, or white matter myelination over time. These findings provide a new perspective on aging effects on brain metal accumulation and structural integrity, highlighting the need for further histological validation to clarify underlying mechanisms.