title: Accurate and simple method for quantification of hepatic fat content using magnetic resonance imaging: a prospective study in biopsy-proven nonalcoholic fatty liver disease.
abstract: BACKGROUND
  To assess the degree of hepatic fat content, simple and noninvasive methods with high objectivity and reproducibility are required. Magnetic resonance imaging (MRI) is one such candidate, although its accuracy remains unclear. We aimed to validate an MRI method for quantifying hepatic fat content by calibrating MRI reading with a phantom and comparing MRI measurements in human subjects with estimates of liver fat content in liver biopsy specimens.
  
  
  METHODS
  The MRI method was performed by a combination of MRI calibration using a phantom and double-echo chemical shift gradient-echo sequence (double-echo fast low-angle shot sequence) that has been widely used on a 1.5-T scanner. Liver fat content in patients with nonalcoholic fatty liver disease (NAFLD, n = 26) was derived from a calibration curve generated by scanning the phantom. Liver fat was also estimated by optical image analysis. The correlation between the MRI measurements and liver histology findings was examined prospectively.
  
  
  RESULTS
  Magnetic resonance imaging measurements showed a strong correlation with liver fat content estimated from the results of light microscopic examination (correlation coefficient 0.91, P < 0.001) regardless of the degree of hepatic steatosis. Moreover, the severity of lobular inflammation or fibrosis did not influence the MRI measurements.
  
  
  CONCLUSIONS
  This MRI method is simple and noninvasive, has excellent ability to quantify hepatic fat content even in NAFLD patients with mild steatosis or advanced fibrosis, and can be performed easily without special devices.
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hatta
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Fujinaga
authors.forename: Masumi
authors.initials: M
authors.lastname: Kadoya
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ueda
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Murayama
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurozumi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ueda
authors.forename: Michiharu
authors.initials: M
authors.lastname: Komatsu
authors.forename: Tadanobu
authors.initials: T
authors.lastname: Nagaya
authors.forename: Satoru
authors.initials: S
authors.lastname: Joshita
authors.forename: Ryo
authors.initials: R
authors.lastname: Kodama
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Uehara
authors.forename: Kenji
authors.initials: K
authors.lastname: Sano
authors.forename: Naoki
authors.initials: N
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005234:Fatty Liver / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008853:Microscopy / Q000379:methods; D008875:Middle Aged; D019047:Phantoms, Imaging; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D055815:Young Adult