title: Feasibility and diagnostic performance of the FibroScan XL probe for liver stiffness measurement in overweight and obese patients.
abstract: Failure of liver stiffness measurement (LSM) by transient elastography (TE, FibroScan) and unreliable results occur in ≈ 5% and 15% of patients, respectively, mainly due to obesity. In this multicenter study, we evaluated the feasibility and performance of the novel FibroScan XL probe in 276 patients with chronic liver disease (42% viral hepatitis, 46% nonalcoholic fatty liver disease [NAFLD]) and a body mass index (BMI) ≥ 28 kg/m(2) . Patients underwent liver biopsy and TE with the standard M and XL probes. TE failure was defined as no valid LSMs and unreliable examinations as <10 valid LSMs or an interquartile range (IQR)/LSM >30% or success rate <60%. Probe performance for diagnosing ≥ F2 fibrosis and cirrhosis (F4) versus biopsy were examined using areas under receiver operating characteristic curves (AUROC). FibroScan failure was less frequent with the XL probe than the M probe (1.1% versus 16%) and the XL probe was more often reliable (73% versus 50%; both P < 0.00005). Reliable results with the XL probe were obtained in 61% of patients in whom the M probe was unreliable. Among 178 patients with ≥ 10 valid LSMs using both probes, liver stiffness was highly correlated between probes (ρ = 0.86; P < 0.0005); however, median liver stiffness was lower using the XL probe (6.8 versus 7.8 kPa; P < 0.00005). The AUROC of the XL and M probes were similar for ≥ F2 fibrosis (0.83 versus 0.86; P = 0.19) and cirrhosis (0.94 versus 0.91; P = 0.28).
  
  
  CONCLUSIONS
  Compared with the M probe, the FibroScan XL probe reduces TE failure and facilitates reliable LSM in obese patients. Although the probes have comparable accuracy, lower liver stiffness cutoffs will be necessary when the XL probe is used to noninvasively assess liver fibrosis.
authors: Liver Unit, Division of Gastroenterology, Department of Medicine, University of Calgary, Calgary, Alberta, Canada. rpmyers@ucalgary.ca
authors: Robert P
authors: RP
authors: Myers
authors: Gilles
authors: G
authors: Pomier-Layrargues
authors: Richard
authors: R
authors: Kirsch
authors: Aaron
authors: A
authors: Pollett
authors: Andres
authors: A
authors: Duarte-Rojo
authors: David
authors: D
authors: Wong
authors: Melanie
authors: M
authors: Beaton
authors: Mark
authors: M
authors: Levstik
authors: Pam
authors: P
authors: Crotty
authors: Magdy
authors: M
authors: Elkashab
mesh_terms: D000328:Adult; D001706:Biopsy; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D005234:Fatty Liver / Q000473:pathology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D009765:Obesity / Q000473:pathology*; D050177:Overweight / Q000473:pathology; D011446:Prospective Studies; D012015:Reference Standards; D015203:Reproducibility of Results