title: Evaluation of Transient Elastography, Acoustic Radiation Force Impulse Imaging (ARFI), and Enhanced Liver Function (ELF) Score for Detection of Fibrosis in Morbidly Obese Patients.
abstract: BACKGROUND
  Liver fibrosis induced by non-alcoholic fatty liver disease causes peri-interventional complications in morbidly obese patients. We determined the performance of transient elastography (TE), acoustic radiation force impulse (ARFI) imaging, and enhanced liver fibrosis (ELF) score for fibrosis detection in bariatric patients.
  
  
  METHODS
  41 patients (median BMI 47 kg/m2) underwent 14-day low-energy diets to improve conditions prior to bariatric surgery (day 0). TE (M and XL probe), ARFI, and ELF score were performed on days -15 and -1 and compared with intraoperative liver biopsies (NAS staging).
  
  
  RESULTS
  Valid TE and ARFI results at day -15 and -1 were obtained in 49%/88% and 51%/90% of cases, respectively. High skin-to-liver-capsule distances correlated with invalid TE measurements. Fibrosis of liver biopsies was staged as F1 and F3 in n = 40 and n = 1 individuals. However, variations (median/range at d-15/-1) of TE (4.6/2.6-75 and 6.7/2.9-21.3 kPa) and ARFI (2.1/0.7-3.7 and 2.0/0.7-3.8 m/s) were high and associated with overestimation of fibrosis. The ELF score correctly classified 87.5% of patients.
  
  
  CONCLUSIONS
  In bariatric patients, performance of TE and ARFI was poor and did not improve after weight loss. The ELF score correctly classified the majority of cases and should be further evaluated.
authors.affiliation: IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany; Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Karlas
authors.affiliation: Department of Visceral, Transplantation, Thoracic and Vascular Surgery, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Dietrich
authors.affiliation: IFB AdiposityDiseases, Research Area Bariatric Surgery, University of Leipzig, Leipzig, Germany.
authors.forename: Veronica
authors.initials: V
authors.lastname: Peter
authors.affiliation: Institute of Pathology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wittekind
authors.affiliation: Institute of Clinical Chemistry, Hannover Medical School, Hannover, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Lichtinghagen
authors.affiliation: IFB AdiposityDiseases, University of Leipzig, Leipzig, Germany; Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Nikita
authors.initials: N
authors.lastname: Garnov
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Linder
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schaudinn
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Busse
authors.affiliation: Coordination Center for Clinical Trials, University of Leipzig, Leipzig, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Prettin
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Keim
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Tröltzsch
authors.affiliation: IFB AdiposityDiseases, Research Area Bariatric Surgery, University of Leipzig, Leipzig, Germany.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Schütz
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Wiegand
mesh_terms: D000328:Adult; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000378:metabolism; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000000981:diagnostic imaging / Q000378:metabolism