Quantitative measurement of brain iron deposition in patients with haemodialysis using susceptibility mapping.

To compare the susceptibility of different brain structures in patients with haemodialysis with that in healthy controls using susceptibility mapping and explore the correlations with neuropsychiatric tests and clinical parameters. Fifty three patients with haemodialysis and forty-five age-and sex-matched healthy controls were recruited in this prospective study. Susceptibility maps (SM) were reconstructed from original phase data and used to compare the susceptibility of different brain structures between patients and healthy controls. The SM was compared with iron predictions from a classic cadaver brain study. Spearman's correlation and stepwise multiple regression analysis between susceptibility and neuropsychiatric tests and clinical parameters were calculated. In patients with haemodialysis, the susceptibility of the bilateral caudate head, putamen, substantia nigra, red nucleus and dentate nucleus were significantly higher than those in healthy controls (P < 0.01). There was positive correlation between susceptibility both from normal controls and patients and iron concentration from a classic post-mortem brain study (both r = 0.900, both P = 0.037). In patients with haemodialysis, the susceptibility of the left putamen (r = 0.944), right putamen (r = 0.882) and right thalamus (r = 0.852) were correlated to dialysis duration (all P < 0.05). The susceptibility of the left caudate head (r = -0.415) and right caudate head (r = -0.311) were mildly negatively correlated with neuropsychiatric test scores (all P < 0.05). In summary, our findings indicated that increased brain iron deposition does occur in patients with haemodialysis and correlated with duration of dialysis.