Diffusion MRI shows increased water apparent diffusion coefficient in the brains of cirrhotics.
BACKGROUND
Brain edema and increased intracranial pressure worsen prognosis in patients with end-stage chronic cirrhosis.


OBJECTIVE
To use diffusion-weighted imaging (DWI) to quantify water apparent diffusion coefficient (ADC) in different brain regions of patients with chronic liver failure with or without hepatic encephalopathy.


METHODS
The authors studied 14 patients with viral liver cirrhosis and 12 sex- and age-matched healthy volunteers. Seven patients had no clinical evidence of hepatic encephalopathy; six had grade I hepatic encephalopathy; and one had grade II hepatic encephalopathy. Brain DWI was obtained using a single-shot echo-planar imaging sequence, and four gradient strengths (b values = 0, 300, 600, and 900 s/mm(2)) were applied to calculate the average diffusivity maps.


RESULTS
Mean ADC values in the brains of patients with cirrhosis were significantly increased in all selected regions of interest (caudate, putamen, and pallidus nuclei; occipital, parietal, and frontal lobe white matter) except in the thalamus. Venous ammonia was linearly related to ADC values in deep gray and white matter regions of interest.


CONCLUSIONS
Brain water apparent diffusion coefficient is increased in patients with chronic liver disease and may be useful in monitoring patients with hepatic encephalopathy.
Department of Clinical Medicine, Internal Medicine and Gastroenterology, University of Bologna, Italy. raffaele.lodi@unibo.it
R
R
Lodi
C
C
Tonon
A
A
Stracciari
M
M
Weiger
V
V
Camaggi
S
S
Iotti
G
G
Donati
M
M
Guarino
L
L
Bolondi
B
B
Barbiroli
D000328:Adult; D000368:Aged; D000641:Ammonia / Q000097:blood; D001921:Brain / Q000378:metabolism*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006501:Hepatic Encephalopathy / Q000378:metabolism*; D006525:Hepatitis, Viral, Human / Q000503:physiopathology; D006801:Humans; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D014867:Water / Q000378:metabolism
D014867:Water; D000641:Ammonia