Quantitative measurements of brain iron deposition in cirrhotic patients using susceptibility mapping

BACKGROUND: Susceptibility-weighted imaging (SWI) has been used to detect micro-bleeds and iron deposits in the brain. However, no reports have been published on the application of SWI in studying iron changes in the brain of cirrhotic patients. PURPOSE: To compare the susceptibility of different brain structures in cirrhotic patients with that in healthy controls and to evaluate susceptibility as a potential biomarker and correlate the measured susceptibility and cadaveric brain iron concentration for a variety of brain structures. MATERIAL AND METHODS: Forty-three cirrhotic patients (27 men, 16 women; mean age, 50 ± 9 years) and 34 age- and sex-matched healthy controls (22 men, 12 women; mean age, 47 ± 7 years) were included in this retrospective study. Susceptibility was measured in the frontal white matter, basal ganglia, midbrain, and dentate nucleus and compared with results gathered from two postmortem brain studies. Correlation between susceptibility and clinical biomarkers and neuropsychiatric tests scores was calculated. RESULTS: In cirrhotic patients, the susceptibility of left frontal white matter, bilateral caudate head, and right substantia nigra was higher than that in healthy controls (P < 0.05). There was a positive correlation between susceptibility and iron concentration from one postmortem brain study (r = 0.835, P = 0.01) in eight deep grey matter structures and another in five brain structures (r = 0.900, P = 0.03). The susceptibility of right caudate head (r = 0.402) and left caudate head (r = 0.408) correlated with neuropsychological test scores (both P < 0.05). CONCLUSION: Abnormal iron deposits occur in cirrhotic patients and abnormal susceptibility of some brain regions appears to reflect neurocognitive changes.