title: Usefulness of percutaneous elastography by acoustic radiation force impulse for the non-invasive diagnosis of chronic pancreatitis.
abstract: OBJECTIVE
  To determine the accuracy of the acoustic radiation force impulse (ARFI) technique for the diagnosis of chronic pancreatitis.
  
  
  METHODS
  We present an observational, single-center study that included patients with suspected chronic pancreatitis in the period between October 2012 and September 2015 who underwent endoscopic ultrasound (EUS) and were classified according to the standard and Rosemont criteria. The same group of patients was assessed by the ARFI technology using ACUSON S2000™ equipment with Virtual Touch™ Quantification software for the assessment of pancreatic stiffness by obtaining the shear wave velocity (SWV) in the head, body and tail of the pancreas. Data were analyzed using ANOVA and nonparametric correlation methods. Diagnostic accuracy was obtained by analyzing receiver operating characteristic (ROC) curve.
  
  
  RESULTS
  A total of thirty-three patients were studied (45.5% women); mean age was 58.3 ± 11.8 years. Seventeen with a diagnosis of chronic pancreatitis and sixteen classified as normal according to standard criteria. A significant difference was detected between the means of SWV in pancreatic body of patients without (SWV: 1.27 m/s) and with chronic pancreatitis (SWV 1.57 m/s), p = 0.037. The area under the ROC curve was 71.3% (95% CI 0.532-0.895) and the accuracy of ARFI for diagnosing chronic pancreatitis was 69.7% for a SWV of 1.4 m/s in the pancreatic body. The SWV means in head (r = 0.421, p < 0.05) and body (r = 0.455, p < 0.05) of the pancreas showed a significant correlation with the number of EUS criteria for chronic pancreatitis.
  
  
  CONCLUSIONS
  Quantification of pancreatic stiffness with ARFI elastography technique has proven to be useful for the non-invasive diagnosis of chronic pancreatitis.
authors.affiliation: Sección de Aparato Digestivo, Hospital General Universitario Rafael Méndez, España.
authors.forename: Camilo Julio
authors.initials: CJ
authors.lastname: Llamoza-Torres
authors.affiliation: Medicina Familiar y Comunitaria Área III, Centro de Salud Lorca-Sur, España.
authors.forename: Maria
authors.initials: M
authors.lastname: Fuentes-Pardo
authors.affiliation: Servicio de Medicina de Aparato Digestivo, Hospital Clínico Universitario Virgen de la Arrixaca, España.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Álvarez-Higueras
authors.affiliation: Servicio de Medicina de Aparato Digestivo., Hospital Clínico Universitario Virgen de la Arrixaca. IMIB-Arrixaca., España.
authors.forename: Fernando
authors.initials: F
authors.lastname: Alberca-de-Las-Parras
authors.affiliation: Servicio de Medicina de Aparato Digestivo, Hospital Clínico Universitario Virgen de la Arrixaca. IMIB-Arrixaca , España.
authors.forename: Fernando
authors.initials: F
authors.lastname: Carballo-Álvarez
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D054459:Elasticity Imaging Techniques / Q000379:methods*; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging; D050500:Pancreatitis, Chronic / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results