title: Impact of acoustic radiation force impulse imaging in clinical practice of patients after orthotopic liver transplantation.
abstract: BACKGROUND
  Acoustic radiation force impulse (ARFI) elastography is a reliable diagnostic device for quantitative non-invasive assessment of liver fibrosis in patients with chronic liver disease. The aim of our prospective study was to evaluate the impact of ARFI in patients after orthotopic liver transplantation (OLT). Therefore, we compared ARFI shear wave velocities with clinical features, non-invasive markers, and the histology of patients following OLT.
  
  
  METHODS
  Post-transplant patients underwent a clinical examination and blood samples were taken. B-mode and Doppler ultrasound (US) of the portal vein and the hepatic artery were performed. Subsequently, a minimum of 10 valid ARFI values were measured in the left and right liver lobe. Liver biopsy was performed if indicated.
  
  
  RESULTS
  Between May 2012 and May 2014, 58 Patients after OLT were included in the prospective study. Laboratory markers and aspartate aminotransferase-to-platelet ratio index (APRI) correlated with ARFI values (r=0.44, p<0.001). The histological (n=22) fibrosis score (Ludwig) was significantly correlated with the ARFI of the biopsy site (r=0.55, p=0.008). The mean shear-wave velocities were significantly increased in advanced fibrosis (F≤2 1.57±0.57 m/s; F≥3 2.85±0.66 m/s; p<0.001), obstructive cholestasis and active viral hepatitis. The area under the receiver operating characteristic (AUROC) curves for the accuracy of ARFI were 74% (F≥1), 73% (F≥2), 93% (F≥3), and 80% (=F4).
  
  
  CONCLUSIONS
  ARFI elastography correlates well with laboratory values and with noninvasive and invasive markers of fibrosis in patients after OLT. In this regard, elevated ARFI-velocities should be interpreted with caution in the context of obstructive cholestasis and active viral disease.
authors.affiliation: Department of Internal Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Dane
authors.initials: D
authors.lastname: Wildner
authors.affiliation: Department of Internal Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Deike
authors.initials: D
authors.lastname: Strobel
authors.affiliation: Department of Internal Medicine II, Thüringen-Klinik, Saalfeld, Germany.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Konturek
authors.affiliation: Department of Internal Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Rüdiger S
authors.initials: RS
authors.lastname: Görtz
authors.affiliation: Department of Surgery, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Roland S
authors.initials: RS
authors.lastname: Croner
authors.affiliation: Department of Internal Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Markus F
authors.initials: MF
authors.lastname: Neurath
authors.affiliation: Department of Internal Medicine 1, University Hospital Erlangen, Erlangen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Zopf
mesh_terms: D000162:Acoustics; D000328:Adult; D000368:Aged; D001219:Aspartate Aminotransferases / Q000097:blood; D001706:Biopsy; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged
chemical_list: D001219:Aspartate Aminotransferases