Assessment of hepatic steatosis and hepatic tissue blood flow by xenon computed tomography in nonalcoholic steatohepatitis.
OBJECTIVE
The diagnosis of non-alcoholic steatohepatitis (NASH) can be difficult using blood tests and imaging studies. Histological diagnosis by liver biopsy remains the gold standard of NASH diagnosis. There is an urgent need to develop and validate simple, reproducible, noninvasive tests to accurately assess NASH stage and grade. We assess the usefulness of xenon computed tomography (Xe-CT), as a non-invasive method of quantitatively and visually determining hepatic tissue blood flows (TBFs), and xenon solubility (lambda value) simultaneously with TBF, in the evaluation of NASH pathophysiology.


METHODS
Histological severity of fatty changes and severity of fibrosis based on Brunt's classification were determined in 38 NASH patients. We evaluated correlations between the grade of fatty changes and lambda value, and correlations between the stage of fibrosis and TBFs.


RESULTS
The lambda value showed significant positive correlations with both grade of steatosis (r = 0.813, P < 0.001) and each 10% range of histological fatty infiltration (r = 0.926, P < 0.001). A significant negative correlation was seen between lambda value and the liver : spleen ratio (r = -0.835, P < 0.001). Portal venous tissue blood flow and total hepatic tissue blood flow showed significant negative correlations with the progression of fibrosis (r = -0.465, P < 0.01; r = -0.433, P < 0.01, respectively). Total hepatic tissue blood flow tended to decrease with progressing grade of steatosis.


CONCLUSIONS
Xe-CT offers a convenient and objective method for evaluating fatty infiltration and changes in blood flow in the entire liver, and appears useful for detailed evaluation of patients with NASH.
Kobayashi
Minoru
M
Division of Gastroenterology and Hepatology, St. Marianna University School of Medicine, Kawasaki, Japan.
Suzuki
Michihiro
M
Ikeda
Hiroki
H
Takahashi
Hideaki
H
Matsumoto
Nobuyuki
N
Maeyama
Shiro
S
Sase
Shigeru
S
Iino
Shiro
S
Itoh
Fumio
F