title: Non-invasive assessment of hepatic steatosis in patients with NAFLD using controlled attenuation parameter and 1H-MR spectroscopy.
abstract: BACKGROUND
  Non-invasive assessment of steatosis and fibrosis is of growing relevance in non-alcoholic fatty liver disease (NAFLD). 1H-Magnetic resonance spectroscopy (1H-MRS) and the ultrasound-based controlled attenuation parameter (CAP) correlate with biopsy proven steatosis, but have not been correlated with each other so far. We therefore performed a head-to-head comparison between both methods.
  
  
  METHODS
  Fifty patients with biopsy-proven NAFLD and 15 healthy volunteers were evaluated with 1H-MRS and transient elastography (TE) including CAP. Steatosis was defined according to the percentage of affected hepatocytes: S1 5-33%, S2 34-66%, S3 ≥67%.
  
  
  RESULTS
  Steatosis grade in patients with NAFLD was S1 36%, S2 40% and S3 24%. CAP and 1H-MRS significantly correlated with histopathology and showed comparable accuracy for the detection of hepatic steatosis: areas under the receiver-operating characteristics curves were 0.93 vs. 0.88 for steatosis ≥S1 and 0.94 vs. 0.88 for ≥S2, respectively. Boot-strapping analysis revealed a CAP cut-off of 300 dB/m for detection of S2-3 steatosis, while retaining the lower cut-off of 215 dB/m for the definition of healthy individuals. Direct comparison between CAP and 1H-MRS revealed only modest correlation (total cohort: r = 0.63 [0.44, 0.76]; NAFLD cases: r = 0.56 [0.32, 0.74]). For detection of F2-4 fibrosis TE had sensitivity and specificity of 100% and 98.1% at a cut-off value of 8.85 kPa.
  
  
  CONCLUSIONS
  Our data suggest a comparable diagnostic value of CAP and 1H-MRS for hepatic steatosis quantification. Combined with the simultaneous TE fibrosis assessment, CAP represents an efficient method for non-invasive characterization of NAFLD. Limited correlation between CAP and 1H-MRS may be explained by different technical aspects, anthropometry, and presence of advanced liver fibrosis.
authors.affiliation: IFB AdiposityDiseases, Leipzig University Medical Center, 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: IFB AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany; Clinical Trial Center, University of Leipzig, Leipzig, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Petroff
authors.affiliation: IFB AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany; Department of Diagnostics and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Nikita
authors.initials: N
authors.lastname: Garnov
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, Section of Hepatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Böhm
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, Section of Hepatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Hannelore
authors.initials: H
authors.lastname: Tenckhoff
authors.affiliation: Institute of Pathology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wittekind
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, Section of Hepatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Wiese
authors.affiliation: Clinic for Gastroenterology and Hepatology, Klinikum St. Georg, Leipzig, Germany.
authors.forename: Ingolf
authors.initials: I
authors.lastname: Schiefke
authors.affiliation: IFB AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany; Department of Diagnostics and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Linder
authors.affiliation: IFB AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany; Department of Diagnostics and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schaudinn
authors.affiliation: Department of Diagnostics and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Busse
authors.affiliation: Department of Diagnostics and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kahn
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Mössner
authors.affiliation: Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, Section of Hepatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Berg
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: 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: IFB AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany; Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, University Hospital Leipzig, Leipzig, Germany; Department of Medicine, Neurology and Dermatology, Division of Gastroenterology and Rheumatology, Section of Hepatology, University Hospital Leipzig, Leipzig, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Wiegand
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D016022:Case-Control Studies; D015897:Comorbidity; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008103:Liver Cirrhosis / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity