title: Correlation of hepatic fractional extracellular space using gadolinium enhanced MRI with liver stiffness using magnetic resonance elastography.
abstract: To compare MR hepatic fractional extracellular space (fECS) to liver stiffness (LS) with magnetic resonance elastography (MRE) for evaluation of liver fibrosis.
  
  
  
  71 consecutive patients with suspected chronic liver disease underwent standard liver MRI with MR elastography and additional delayed Gd-DTPA-enhanced sequences at 5 and 10 min in order to calculate hepatic fECS (%) and LS (kilopascals, kPa). Two radiologists blinded to clinical history examined MR images and calculated fECS and LS in identical locations for every patient. Interobserver agreement was calculated using the intraclass correlation coefficient. Pearson's correlation was calculated for LS and fECS measures, as was the area under the receiver operatic curve (AUROC), sensitivity and specificity of fECS to predict liver stiffness ≥2.93 and ≥5 kPa. The sensitivity of fECS for detecting fibrosis was separately analyzed in the subgroup of patients without anatomic findings of cirrhosis.
  
  
  
  Substantial to excellent interobserver agreement for both LS and fECS measurements was seen with intraclass correlation of 0.88 (95% CI 0.81-0.92) for LS, 0.77 (95% CI 0.66-0.85) for fECS5and 0.76 (95% CI 0.64-0.84) for fECS10. A significant correlation was found between MRE and fECS5(r = 0.47, p < 0.0001) and fECS10(r = 0.44, p < 0.0001). The performance of fECS improved for detection of advanced fibrosis (≥5 kPa) with AUROC, sensitivity and specificity of 0.72, 38%, and 94% for fECS5and 0.72, 67%, and 66% for fECS10.
  
  
  
  fECS correlates modestly with MRE-determined LS. fECS at MRI is a simple calculation to perform and may represent a practical way to suggest the presence of fibrosis during routine liver evaluation.
authors: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors: Michael L
authors: ML
authors: Wells
authors: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors: Michael R
authors: MR
authors: Moynagh
authors: Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.
authors: Rickey E
authors: RE
authors: Carter
authors: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors: Robert A
authors: RA
authors: Childs
authors: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors: Cameron E
authors: CE
authors: Leitch
authors: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors: Joel G
authors: JG
authors: Fletcher
authors: Department of Radiology, University of California San Francisco, San Francisco, CA, USA.
authors: Benjamin M
authors: BM
authors: Yeh
authors: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA. Venkatesh.Sudhakar@mayo.edu.
authors: Sudhakar K
authors: SK
authors: Venkatesh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005110:Extracellular Space / Q000000981:diagnostic imaging*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA
keywords: Fractional extracellular space; Gadolinium; Hepatic extracellular space; Hepatic fibrosis; Liver fibrosis; Liver stiffness; MR elastography; MRI