title: Noninvasive assessment of liver fibrosis with acoustic radiation force impulse imaging: increased liver and splenic stiffness in patients with liver fibrosis and cirrhosis.
abstract: OBJECTIVE
  To evaluate acoustic radiation force impulse imaging (ARFI) of the liver and spleen as a new method for the noninvasive assessment of liver fibrosis (LF).
  
  
  METHODS
  Three groups of 58 examinees were studied: (A) 20 healthy volunteers; (B) 18 patients with chronic viral hepatitis (CVH) B or C having liver fibrosis stages F 1 - 4 (assessed by liver biopsy; Ishak classification); and (C) 20 patients with liver cirrhosis (LC). All participants were examined using the Siemens ACUSON S 2000 Ultrasound Virtual Touch Tissue Quantification system. Ten measurements were performed on both liver lobes and three measurements on the spleen, and the obtained mean values (shear wave velocities [SWV] expressed in m/s) were compared between the groups. In 20 patients the splenic artery pulsatility index (SAPI) was also measured and correlated to the liver and splenic ARFI and histological stage of LF.
  
  
  RESULTS
  Hepatic ARFI measurements demonstrated a significant correlation to LB results (Spearman's ρ = 0.766; ρ < 0.001) and SWV cut-off values of 1.3 (AUC 0.96) and 1.86 (AUC 0.99) could reliably differentiate between healthy (A) and non-cirrhotic CVH (B), as well as between non-cirrhotic CVH (B) and LC (C). Splenic SWV cut-off value of 2.73 (AUC 0.82) could differentiate between the patients with LC and non-cirrhotic CVH. A significant correlation was also observed between the SAPI and liver ARFI results (ρ = 0.56; p = 0.013).
  
  
  CONCLUSIONS
  The hepatic and splenic SWV measured by ARFI increase with the LF stage, and the hepatic SWV correlate well with SAPI. This new technology enables simultaneous morphological, Doppler and elastometric examinations and might improve the accuracy of noninvasive liver fibrosis assessment.
authors.affiliation: Gastroenterology, University of Zagreb, University Hospital Dubrava, Zagreb.
authors.forename: I
authors.initials: I
authors.lastname: Grgurevic
authors.forename: I
authors.initials: I
authors.lastname: Cikara
authors.forename: J
authors.initials: J
authors.lastname: Horvat
authors.forename: I K
authors.initials: IK
authors.lastname: Lukic
authors.forename: R
authors.initials: R
authors.lastname: Heinzl
authors.forename: M
authors.initials: M
authors.lastname: Banic
authors.forename: M
authors.initials: M
authors.lastname: Kujundzic
authors.forename: B
authors.initials: B
authors.lastname: Brkljacic
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001783:Blood Flow Velocity / Q000502:physiology; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging; D019694:Hepatitis B, Chronic / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D019698:Hepatitis C, Chronic / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008103:Liver Cirrhosis / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology; D012016:Reference Values; D012680:Sensitivity and Specificity; D013154:Spleen / Q000000981:diagnostic imaging / Q000473:pathology; D013157:Splenic Artery / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler; D018615:Ultrasonography, Doppler, Color / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult