Brain iron deposition and cognitive decline in patients with cerebral small vessel disease : a quantitative susceptibility mapping study

Quantitative susceptibility mapping (QSM) can study the susceptibility values of brain tissue which allows for noninvasive examination of local brain iron levels in both normal and pathological conditions. Our study compares brain iron deposition in gray matter (GM) nuclei between cerebral small vessel disease (CSVD) patients and healthy controls (HCs), exploring factors that affect iron deposition and cognitive function. A total of 321 subjects were enrolled in this study. All subjects had cognitive examination including the Stroop color word test (SCWT) and MRI including multiecho gradient echo (mGRE) sequence. The patients with CSVD were divided into mild to moderate group (CSVD-M, total CSVD score ≤ 1) and severe group (CSVD-S, total CSVD score > 1). Morphology-enabled dipole inversion with an automated uniform cerebrospinal fluid zero reference algorithm (MEDI + 0) was used to generate brain QSM maps from mGRE data. Deep gray regional susceptibility values and cognitive function were compared among three groups (CSVD-S, CSVD-M, and HC) using multiple linear regression analysis and mediation effect analysis. There were significant differences in the SCWT scores and mean susceptibility values of the globus pallidus (GP), putamen (Put), and caudate nucleus (CN) among the three groups (P