Value of the apparent diffusion coefficient for quantification of low-grade hepatic encephalopathy.
OBJECTIVE
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.
Department of Gastroenterology and Hepatology, Division of Clinical Medicine and Biomedical Sciences, Institute of Medical Science, Mie University Graduate School of Medicine, Tsu, Japan.
Ryosuke
R
Sugimoto
Motoh
M
Iwasa
Masayuki
M
Maeda
Naohito
N
Urawa
Hideaki
H
Tanaka
Naoki
N
Fujita
Yoshinao
Y
Kobayashi
Kan
K
Takeda
Masahiko
M
Kaito
Yoshiyuki
Y
Takei
D000368:Aged; D000641:Ammonia / Q000097:blood; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006501:Hepatic Encephalopathy / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism*; D006801:Humans; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000473:pathology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D015203:Reproducibility of Results
D000641:Ammonia