Cognitive impairment is associated with iron accumulation in the hippocampus following ICH (A) Axial MRI images of basal ganglia (dashed rectangle) and hippocampus (dashed irregular) of healthy controls and ICH patients. (B–C) Axial SWI phase images showing the interesting region of healthy controls (n = 30) and ICH patients (n = 91). Black arrows indicate the regions of interest. Quantification and comparison of phase shift values used in quantitative analysis of iron content, MoCA score and MMSE score used to evaluated cognition of healthy controls and ICH patients. (D–E) Axial QSM reconstruction conducted from SWI phase of healthy controls (N = 10) and ICH patients (n = 10). White arrows indicate the regions of interest. Quantification and comparison of magnetic susceptibility of healthy controls and ICH patients. (F) Quantification and comparison of CSF iron level of healthy control (n = 11) and ICH patients (n = 11) at day 3, day 7 and day 28 after onset. (G–H) Axial SWI phase images showing hippocampal regions of interest in ICH with (n = 30) and without (n = 61) cognitive impairment (CI) for quantitative analysis of iron content. Black arrows indicate the regions of interest. Quantification and comparison of phase shift values used in quantitative analysis of iron content, MoCA score and MMSE score of ICH patients with or without cognitive impairments. (I) Spearman correlation coefficient and linear regression analyses were adopted to investigate the associations between Phase shift value and MoCA or MMSE score in ICH patients. (C, E, F) *P < 0.05; **P < 0.01; ***P < 0.001 vs corresponding Control. (H) ***P < 0.001 vs corresponding ICH without CI.