title: Reliability and applicability of two-dimensional shear-wave elastography for the evaluation of liver stiffness.
abstract: OBJECTIVE
  Two-dimensional shear-wave elastography (2D-SWE) is a new elastographic technique that is increasingly being used across several indications. We assessed the reliability and applicability of 2D-SWE in patients with various chronic liver diseases and attempted to identify parameters potentially affecting liver stiffness.
  
  
  METHODS
  We included all patients with chronic liver disease who underwent 2D-SWE examination over a 15-month period. Patients with acute hepatitis, active cholestatic disease, or severe heart failure were excluded. The procedures were performed by three adequately trained operators. Standard operating procedures for liver ultrasonography and elastography were followed.
  
  
  RESULTS
  2D-SWE was reliable in 98% of 605 patients. SD to mean liver stiffness value ratio greater than 9.14%, which was considered an indicator of reliability, was associated independently with age more than 50 years, obesity, or overweight, and use of statins for hyperlipidemia. 2D-SWE was applicable, requiring a median time of 7 min per examination and exceeding 15 min in only 5.5% of patients. Worse applicability expressed as duration more than 0.7 min per reliable measurement was associated independently with age more than 50 years and obesity. The mean and median liver stiffness values were 11.6 and 7.7 kPa, respectively. Liver stiffness more than 7.7 kPa was associated independently with age more than 50 years and increased waist circumference.
  
  
  CONCLUSIONS
  2D-SWE represents an applicable method of assessment of liver fibrosis that can provide reliable results in the vast majority of patients with chronic liver diseases. Older age and obesity may affect the reliability and applicability of the method as well as the severity of liver fibrosis.
authors.affiliation: aAcademic Department of Gastroenterology bFirst Department of Surgery, Medical School of National and Kapodistrian University of Athens, Laiko General Hospital cPaediatric Clinic, 'P. & A. Kyriakou' Children's Hospital, Faculty of Nursing, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Ioannis C
authors.initials: IC
authors.lastname: Varbobitis
authors.forename: Spyros I
authors.initials: SI
authors.lastname: Siakavellas
authors.forename: Ioannis S
authors.initials: IS
authors.lastname: Koutsounas
authors.forename: Dimitrios S
authors.initials: DS
authors.lastname: Karagiannakis
authors.forename: Panagiota
authors.initials: P
authors.lastname: Ioannidou
authors.forename: Maria-Vasiliki
authors.initials: MV
authors.lastname: Papageorgiou
authors.forename: Ioanna D
authors.initials: ID
authors.lastname: Pavlopoulou
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Schizas
authors.forename: Giorgos
authors.initials: G
authors.lastname: Bamias
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vlachogiannakos
authors.forename: Spyros D
authors.initials: SD
authors.lastname: Ladas
authors.forename: George V
authors.initials: GV
authors.lastname: Papatheodoridis
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000473:pathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index; D055105:Waist Circumference; D055815:Young Adult