title: Estimating steatosis and fibrosis: Comparison of acoustic structure quantification with established techniques.
abstract: OBJECTIVE
  To compare ultrasound-based acoustic structure quantification (ASQ) with established non-invasive techniques for grading and staging fatty liver disease.
  
  
  METHODS
  Type 2 diabetic patients at risk of non-alcoholic fatty liver disease (n = 50) and healthy volunteers (n = 20) were evaluated using laboratory analysis and anthropometric measurements, transient elastography (TE), controlled attenuation parameter (CAP), proton magnetic resonance spectroscopy ((1)H-MRS; only available for the diabetic cohort), and ASQ. ASQ parameters mode, average and focal disturbance (FD) ratio were compared with: (1) the extent of liver fibrosis estimated from TE and non-alcoholic fatty liver disease (NAFLD) fibrosis scores; and (2) the amount of steatosis, which was classified according to CAP values.
  
  
  RESULTS
  Forty-seven diabetic patients (age 67.0 ± 8.6 years; body mass index 29.4 ± 4.5 kg/m²) with reliable CAP measurements and all controls (age 26.5 ± 3.2 years; body mass index 22.0 ± 2.7 kg/m²) were included in the analysis. All ASQ parameters showed differences between healthy controls and diabetic patients (P < 0.001, respectively). The ASQ FD ratio (logarithmic) correlated with the CAP (r = -0.81, P < 0.001) and (1)H-MRS (r = -0.43, P = 0.004) results. The FD ratio [CAP < 250 dB/m: 107 (102-109), CAP between 250 and 300 dB/m: 106 (102-114); CAP between 300 and 350 dB/m: 105 (100-112), CAP ≥ 350 dB/m: 102 (99-108)] as well as mode and average parameters, were reduced in cases with advanced steatosis (ANOVA P < 0.05). However, none of the ASQ parameters showed a significant difference in patients with advanced fibrosis, as determined by TE and the NAFLD fibrosis score (P > 0.08, respectively).
  
  
  CONCLUSIONS
  ASQ parameters correlate with steatosis, but not with fibrosis in fatty liver disease. Steatosis estimation with ASQ should be further evaluated in biopsy-controlled studies.
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Karlas
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Berger
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Nikita
authors.initials: N
authors.lastname: Garnov
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Lindner
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Busse
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Linder
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schaudinn
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Relke
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Rima
authors.initials: R
authors.lastname: Chakaroun
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Tröltzsch
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Wiegand
authors.affiliation: Thomas Karlas, Nikita Garnov, IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Keim
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D066244:Proton Magnetic Resonance Spectroscopy; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Controlled attenuation parameter; Fibrosis score; Liver stiffness; Non-alcoholic fatty liver disease; Transient elastography