Quantitative magnetic resonance imaging in patients with cirrhosis: a cross-sectional study.

Cerebral magnetic resonance imaging was undertaken, at 3 Tesla field strength, employing magnetization transfer (MT) and diffusion-weighted imaging (DWI) sequences, in 26 patients with well-compensated cirrhosis, free of overt hepatic encephalopathy. Results were compared to those from 18 aged-matched healthy volunteers. Cerebral magnetization transfer ratios (MTR) were reduced in the frontal white matter, caudate, putamen and globus pallidus in patients with cirrhosis, compared to healthy controls, while the apparent diffusion coefficients (ADC) on DWI were significantly increased in the genu and body of the corpus callosum. An association between previous excessive alcohol consumption and both MTR and ADCs was noted, but this association was lost when controls were exercised for the severity of liver disease and psychometric impairment on multivariate analysis. Eight (31 %) of the 26 patients had impaired psychometric performance consistent with a diagnosis of minimal hepatic encephalopathy. No statistically significant difference in regional cerebral MTRs or ADCs was found in relation to neuropsychiatric status, although there was a trend towards lower MTRs in patients with impaired psychometric performance. The alterations in MTR and ADC in the patients with functionally compensated cirrhosis are compatible with theories governing the genesis of hepatic encephalopathy, including changes in astrocyte membrane permeability, with subsequent redistribution of macromolecules.