title: Non-alcoholic fatty liver disease: spectral patterns observed from an in vivo phosphorus magnetic resonance spectroscopy study.
abstract: OBJECTIVE
  Liver biopsy is the gold standard for diagnosing non-alcoholic fatty liver disease (NAFLD) but with practical constraints. Phosphorus magnetic resonance spectroscopy ((31)P-MRS) allows in vivo assessment of hepatocellular metabolism and has shown potential for biochemical differentiation in diffuse liver disease. Our aims were to describe spectroscopic signatures in biopsy-proven NAFLD and to determine diagnostic performance of (31)P-MRS for non-alcoholic steatohepatitis (NASH).
  
  
  METHODS
  (31)P-MRS was performed in 151 subjects, comprised of healthy controls (n=19) and NAFLD patients with non-NASH (n=37) and NASH (n=95). Signal intensity ratios for phosphomonoesters (PME) including phosphoethanolamine (PE), phosphodiesters (PDE) including glycerophosphocholine (GPC), total nucleotide triphosphate (NTP) including α-NTP, and inorganic phosphate (Pi), expressed relative to total phosphate (TP) or [PME+PDE] and converted to percentage, were obtained.
  
  
  RESULTS
  Compared to controls, both NAFLD groups had increased PDE/TP (p<0.001) and decreased Pi/TP (p=0.011). Non-NASH patients showed decreased PE/[PME+PDE] (p=0.048), increased GPC/[PME+PDE] (p<0.001), and normal NTP/TP and α-NTP/TP. Whereas, NASH patients had normal PE/[PME+PDE] and GPC/[PME+PDE], but decreased NTP/TP (p=0.004) and α-NTP/TP (p<0.001). The latter was significantly different between non-NASH and NASH (p=0.047) and selected as discriminating parameter, with area under the receiver-operating characteristics curve of 0.71 (95% confidence interval, 0.62-0.79). An α-NTP/TP cutoff of 16.36% gave 91% sensitivity and cutoff of 10.57% gave 91% specificity for NASH.
  
  
  CONCLUSIONS
  (31)P-MRS shows distinct biochemical changes in different NAFLD states, and has fair diagnostic accuracy for NASH.
authors.affiliation: Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Jill M
authors.initials: JM
authors.lastname: Abrigo
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Jiayun
authors.initials: J
authors.lastname: Shen
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Vincent W-S
authors.initials: VW
authors.lastname: Wong
authors.affiliation: Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: David K-W
authors.initials: DK
authors.lastname: Yeung
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Grace L-H
authors.initials: GL
authors.lastname: Wong
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Angel M-L
authors.initials: AM
authors.lastname: Chim
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Anthony W-H
authors.initials: AW
authors.lastname: Chan
authors.affiliation: Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Paul C-L
authors.initials: PC
authors.lastname: Choi
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Francis K-L
authors.initials: FK
authors.lastname: Chan
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong. Electronic address: hlychan@cuhk.edu.hk.
authors.forename: Henry L-Y
authors.initials: HL
authors.lastname: Chan
authors.affiliation: Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong; Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong. Electronic address: winnie@med.cuhk.edu.hk.
authors.forename: Winnie C-W
authors.initials: WC
authors.lastname: Chu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004983:Ethanolamines / Q000378:metabolism; D005260:Female; D005997:Glycerylphosphorylcholine / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D009711:Nucleotides / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*
chemical_list: D004983:Ethanolamines; D009711:Nucleotides; D010710:Phosphates; D010758:Phosphorus; D005997:Glycerylphosphorylcholine; C005448:phosphorylethanolamine
keywords: Adenosine triphosphate; Liver fibrosis; Non-alcoholic steatohepatitis; Phosphorus metabolites; Simple steatosis