title: T1-weighted dual-echo MRI for fat quantification in pediatric nonalcoholic fatty liver disease.
abstract: OBJECTIVE
  To determine in obese children with nonalcoholic fatty liver disease (NAFLD) the accuracy of magnetic resonance imaging (MRI) in assessing liver fat concentration.
  
  
  METHODS
  A case-control study was performed. Cases were 25 obese children with biopsy-proven NAFLD. Controls were 25 obese children matched for age and gender, without NAFLD at ultrasonography and with normal levels of aminotransferases and insulin. Hepatic fat fraction (HFF) by MRI was obtained using a modification of the Dixon method.
  
  
  RESULTS
  HFF ranged from 2% to 44% [mean, 19.0% (95% CI, 15.1-27.4)] in children with NAFLD, while in the controls this value ranged from 0.08% to 4.69% [2.0% (1.3-2.5), P < 0.0001]. HFF was highly correlated with histological steatosis (r = 0.883, P < 0.0001) in the NAFLD children. According to the histological grade of steatosis, the mean HFF was 8.7% (95% CI, 6.0-11.6) for mild, 21.6% (15.3-27.0) for moderate, and 39.7% (34.4-45.0) for severe fatty liver infiltration. With a cutoff of 4.85%, HFF had a sensitivity of 95.8% for the diagnosis of histological steatosis ≥ 5%. All control children had HFF lower than 4.85%; thus, the specificity was 100%. After 12 mo, children with weight loss displayed a significant decrease in HFF.
  
  
  CONCLUSIONS
  MRI is an accurate methodology for liver fat quantification in pediatric NAFLD.
authors.affiliation: Department of Pediatrics, Sapienza University of Rome, Viale Regina Elena 324, 00161-Rome, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pacifico
authors.forename: Michele Di
authors.initials: MD
authors.lastname: Martino
authors.forename: Carlo
authors.initials: C
authors.lastname: Catalano
authors.forename: Valeria
authors.initials: V
authors.lastname: Panebianco
authors.forename: Mario
authors.initials: M
authors.lastname: Bezzi
authors.forename: Caterina
authors.initials: C
authors.lastname: Anania
authors.forename: Claudio
authors.initials: C
authors.lastname: Chiesa
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000293:Adolescent; D015992:Body Mass Index; D016022:Case-Control Studies; D002648:Child; D005234:Fatty Liver / Q000473:pathology*; D005260:Female; D006801:Humans; D008099:Liver / Q000201:enzymology / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D065626:Non-alcoholic Fatty Liver Disease; D009765:Obesity / Q000473:pathology; D012680:Sensitivity and Specificity; D000637:Transaminases / Q000097:blood
chemical_list: D000637:Transaminases