Value of the apparent diffusion coefficient for quantification of low-grade hepatic encephalopathy

Am J Gastroenterol. 2008 Jun;103(6):1413-20. doi: 10.1111/j.1572-0241.2008.01788.x. Epub 2008 May 28.


Background and aims: Minimal hepatic encephalopathy (HE) is associated with poorer quality of life and increased work disability. Recently, low-grade cerebral edema has been implicated in chronic liver disease.

Methods: We measured the apparent diffusion coefficient (ADC) of water in various regions of the brains of patients with cirrhosis, and elucidated the significance of the evaluation of ADC in quantifying low-grade HE and predicting overt HE and survival. Forty patients with cirrhosis and 24 controls underwent diffusion-weighted imaging, and patients were followed up every month.

Results: The mean ADC values were increased in cirrhotic patients with minimal HE versus no HE or controls. Minimal HE patients separated from no HE patients with a sensitivity of 70 approximately 90% and a specificity of 85 approximately 90%. ADC values correlated with individual neuropsychological tests. ADC values of white matter, such as the frontal (log-rank test 4.35, P < 0.05) and parietal (log-rank test 5.98, P < 0.05) white matter, was predictive of further bouts of overt HE.

Conclusions: ADC is a reliable tool for quantification of low-grade HE, and could predict the development of overt HE.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Aged
  • Ammonia / blood
  • Brain / metabolism*
  • Brain / pathology
  • Cohort Studies
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Hepatic Encephalopathy / diagnosis*
  • Hepatic Encephalopathy / etiology
  • Hepatic Encephalopathy / metabolism*
  • Humans
  • Liver Cirrhosis / metabolism*
  • Liver Cirrhosis / pathology
  • Liver Cirrhosis / psychology*
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Predictive Value of Tests
  • Reproducibility of Results


  • Ammonia