title: Magnetic resonance elastography of liver in healthy Asians: normal liver stiffness quantification and reproducibility assessment.
abstract: OBJECTIVE
  To determine normal liver stiffness values evaluated with magnetic resonance elastography (MRE) in healthy normal Asian volunteers and assess its reproducibility.
  
  
  METHODS
  Liver stiffness was evaluated with MRE in 41 healthy Asians (23 females, 18 males; mean age, 41.8 years, and mean body mass index [BMI], 23.4 kg/m(2) ) on a 1.5T clinical scanner. The correlations between mean liver stiffness and age, gender, BMI, and fat fraction percentage of the liver were studied. Another 12 volunteers underwent liver MRE exams on two separate days 4-6 weeks apart under similar conditions for reproducibility assessment. Intraclass correlation coefficient (ICC) analysis was performed and within-subject coefficient of variation (CV) of stiffness was estimated.
  
  
  RESULTS
  The mean ± standard deviation (SD) of liver stiffness in normal healthy Asian subjects was 2.09 ± 0.22 kPa (95% confidence interval [CI], 2.04-2.15 kPa; range 1.68-2.48 kPa). The mean liver stiffness did not significantly correlate with age, gender, BMI, or fat content of the liver. The ICC for mean liver stiffness was 0.90 (95% CI, 0.78-0.96) and CV ranged from 2.2%-11.4%.
  
  
  CONCLUSIONS
  The liver stiffness in normal Asians is not affected by age, gender, BMI, or fat content. Liver stiffness with MRE is highly reproducible.
authors.affiliation: Radiology, Mayo Clinic, Rochester, Minnesota, USA; Diagnostic Imaging, National University Health System, Singapore.
authors.forename: Sudhakar K
authors.initials: SK
authors.lastname: Venkatesh
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Lynette L S
authors.initials: LL
authors.lastname: Teo
authors.forename: Bertrand W L
authors.initials: BW
authors.lastname: Ang
mesh_terms: D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results
keywords: age; gender; liver stiffness measurement; magnetic resonance elastography; normal healthy subjects; reproducibility