title: Magnetic resonance elastography of the liver in patients status-post fontan procedure: feasibility and preliminary results.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the feasibility of performing magnetic resonance elastography (MRE) as a screening tool for elevated liver stiffness in patients' status-post Fontan procedure.
  
  
  BACKGROUND
  With greater numbers of Fontan patients surviving far into adulthood, a factor increasingly affecting long-term prognosis is the presence of hepatic congestion and fibrosis. If detected early, steps can be taken to potentially slow or halt the progression of fibrosis. MRE is a relatively new, noninvasive imaging technique, which can quantitatively measure liver stiffness and provide an estimate of the extent of fibrosis.
  
  
  METHODS
  A retrospective study was conducted using MRE to evaluate liver stiffness in patients with a history of Fontan procedure. An MRE was performed in the same session as a clinical cardiac MRI. The liver was interrogated at four slice locations, and a mean liver stiffness value was calculated for each patient using postprocessing software. The medical records were reviewed for demographic and clinical characteristics.
  
  
  RESULTS
  During the time frame of this investigation, 17 MRE exams were performed on 16 patients. All patients had elevated liver stiffness values as defined by MRE standards. The median of the individual mean liver stiffness values was 5.1 kPa (range: 3.4-8.2 kPa). This range of liver stiffness elevation would suggest the presence of mild to severe fibrosis in a patient with standard cardiovascular anatomy. We found a significant trend toward higher liver stiffness values with greater duration of Fontan circulation (rs = 0.55, P = .02).
  
  
  CONCLUSIONS
  Our preliminary findings suggest that MRE is a feasible method for evaluating the liver in Fontan patients who are undergoing surveillance cardiac MRI. Further investigation with histologic correlation is needed to determine the contributions of hepatic congestion and fibrosis to the liver stiffness in this population.
authors.affiliation: Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: Suraj D
authors.initials: SD
authors.lastname: Serai
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Wallihan
authors.forename: Sudhakar K
authors.initials: SK
authors.lastname: Venkatesh
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Campbell
authors.forename: Joshua
authors.initials: J
authors.lastname: Sticka
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Marino
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Podberesky
mesh_terms: D000293:Adolescent; D000328:Adult; D002496:Central Venous Pressure; D002648:Child; D004548:Elasticity; D054459:Elasticity Imaging Techniques; D005240:Feasibility Studies; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects*; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D012984:Software; D016896:Treatment Outcome; D055815:Young Adult
keywords: Elastography; Fontan; MRE; Pediatric; liver biopsy