title: Liver stiffness measured by acoustic radiation force impulse elastography reflects the severity of liver damage and prognosis in patients with acute liver failure.
abstract: OBJECTIVE
  We measured liver stiffness (LS) in patients with acute liver failure (ALF) using acoustic radiation force impulse (ARFI) elastography and investigated the usefulness of measuring LS for predicting the prognosis of ALF patients.
  
  
  METHODS
  From April 2010 to December 2013, we evaluated 63 patients with acute liver disease. The subjects included 41 patients with acute hepatitis (AH), 16 patients with severe AH (SAH), who had no hepatic encephalopathy despite plasma prothrombin time of 40% or less, and six patients with fulminant hepatitis (FH) diagnosed according to the criteria of the Japanese Study Group. The relationships among shear wave velocity (SWV), clinical diagnosis, liver function tests and prognosis were evaluated. Receiver-operator curve (ROC) analysis was performed to investigate whether ARFI elastography exhibits potential usefulness for the prediction of FH.
  
  
  RESULTS
  The mean SWV on admission were 1.98 ± 0.55, 2.61 ± 0.58 and 3.66 ± 0.86 m/s in the AH, SAH and FH groups, respectively. The SWV was significantly higher in the FH group than in the other groups (P < 0.001), and in the SAH group than in the AH group (P = 0.002). The area under the ROC for predicting FH was 0.924 (sensitivity, 83.3%; specificity, 93.0%). The SWV was significantly increased in non-survivors, while remaining decreased in survivors (P = 0.002).
  
  
  CONCLUSIONS
  The SWV measured by ARFI elastography reflects severity of liver damage, and serial changes in SWV predict the prognosis of ALF patients. The SWV is an early and precise biomarker of FH.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Iwate Medical University, Morioka, Japan.
authors.forename: Hidekatsu
authors.initials: H
authors.lastname: Kuroda
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kakisaka
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Oikawa
authors.forename: Mio
authors.initials: M
authors.lastname: Onodera
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Kei
authors.initials: K
authors.lastname: Sawara
authors.forename: Ryujin
authors.initials: R
authors.lastname: Endo
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takikawa
keywords: acoustic radiation force impulse elastography; acute liver failure; liver stiffness; prognosis; shear wave velocity