title: Accuracy of endoscopic ultrasound elastography used for differential diagnosis of focal pancreatic masses: a multicenter study.
abstract: OBJECTIVE
  Endoscopic ultrasound (EUS) elastography represents a new imaging procedure that might characterize the differences of hardness and strain between diseased tissue and normal tissue. The aim of this study was to assess the efficiency of EUS elastography for the differentiation of focal masses in chronic pancreatitis and pancreatic cancer.
  
  
  METHODS
  The study group comprised 258 patients with focal pancreatic masses included prospectively at 13 participating centers. Qualitative analysis of the diagnoses made by two expert doctors using all recorded video clips was performed in order to test the interobserver variability. A post-processing software analysis was used to examine the EUS elastography videos by calculating average-hue histograms of individual elastography images. The quantitative information was used to calculate intra-observer variability and the accuracy of the method.
  
  
  RESULTS
  Qualitative analysis of the recorded videos revealed a kappa value of 0.72. Intra-observer variability analysis revealed that the single measure intraclass correlation ranged between 0.86 and 0.94. The average-hue histogram analysis of the data indicated a sensitivity of 93.4 %, a specificity of 66.0 %, a positive predictive value of 92.5 %, a negative predictive value of 68.9 %, and an overall accuracy of 85.4 %, based on a cut-off value of 175. Area under the receiver operating characteristic curve (AUROC) was 0.854 ( P < 0.0001) with a confidence interval of 0.804 - 0.894.
  
  
  CONCLUSIONS
  The value of quantitative analysis of EUS elastography recordings was proven by good reproducibility of the videos, as well as good parameters of the AUROC analysis. (Clinical Trials.gov identifier: CT00909103).
authors: Gastroenterology Department, University of Medicine and Pharmacy, Craiova, Romania. adry@umfcv.ro
authors: A
authors: A
authors: Săftoiu
authors: P
authors: P
authors: Vilmann
authors: F
authors: F
authors: Gorunescu
authors: J
authors: J
authors: Janssen
authors: M
authors: M
authors: Hocke
authors: M
authors: M
authors: Larsen
authors: J
authors: J
authors: Iglesias-Garcia
authors: P
authors: P
authors: Arcidiacono
authors: U
authors: U
authors: Will
authors: M
authors: M
authors: Giovannini
authors: C
authors: C
authors: Dietrich
authors: R
authors: R
authors: Havre
authors: C
authors: C
authors: Gheorghe
authors: C
authors: C
authors: McKay
authors: D I
authors: DI
authors: Gheonea
authors: T
authors: T
authors: Ciurea
mesh_terms: D000328:Adult; D000368:Aged; D003936:Diagnosis, Computer-Assisted; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods*; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D050500:Pancreatitis, Chronic / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016037:Single-Blind Method