title: The liver to abdominal area ratio (LAAR): a novel imaging score for prognostication in cirrhosis.
abstract: BACKGROUND
  Anecdotally, liver size is important in determining prognosis in patients with end-stage liver disease (ESLD).
  
  
  OBJECTIVE
  To assess if a ratio of liver area and abdominal area on cross-sectional imaging could accurately predict mortality in ESLD.
  
  
  METHODS
  A retrospective-prospective cohort study was performed on patients with ESLD in a training set. The censor point used was date of patient death or liver transplant (LT). The liver to abdominal area ratio (LAAR) was calculated using the formula {LAAR = [liver area (cm(2))/abdominal area (cm(2))] × 100}. A validation set was collected from a different institution.
  
  
  RESULTS
  Three hundred and sixteen patients were identified. Complete imaging and survival data were available in 158 subjects, 100 male (63%). The LAAR score detected progression to death/LT in our cohort (P < 0.003). Its prognostic accuracy at 90, 360 and 720 days, using the optimal cut-off (32.1), from baseline CT date to death/LT using the log-rank test was P = 0.28, P = 0.06 (OR 1.347, 95% CI 0.94-1.94) and P < 0.0001 (OR 1.89, 95% CI 1.25-2.85) respectively. On multivariate analysis, LAAR (P = 0.008), MELD (P = 0.004) and MELD-Na (P = 0.03) were independently associated with the primary study outcome measurement at 720 days. The validation set of 52 patients confirmed the utility of the LAAR to determine risk of death or need for LT, AUROC 0.89 (0.78-0.97), and P < 0.0001.
  
  
  CONCLUSIONS
  The liver to abdominal area ratio (LAAR) score offers a new paradigm in disease modelling in end-stage liver disease (ESLD) and offers prognostic accuracy at 2 years from computer tomography (CT) imaging.
authors.affiliation: Department of Hepatology, The Royal Liverpool Hospital, Liverpool, UK.
authors.forename: T J S
authors.initials: TJ
authors.lastname: Cross
authors.forename: M
authors.initials: M
authors.lastname: Joseph
authors.forename: R A M
authors.initials: RA
authors.lastname: Fernando
authors.forename: C
authors.initials: C
authors.lastname: Farrell
authors.forename: J D
authors.initials: JD
authors.lastname: Mitchell
mesh_terms: D000005:Abdomen / Q000473:pathology; D000328:Adult; D019412:Anatomy, Cross-Sectional; D058625:End Stage Liver Disease / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009929:Organ Size; D011379:Prognosis; D011446:Prospective Studies; D011860:Radiography, Abdominal; D012189:Retrospective Studies; D012720:Severity of Illness Index