title: Acoustic radiation force impulse with shear wave speed quantification of pancreatic masses: A prospective study.
abstract: BACKGROUND
  Acoustic Radiation Force Impulse (ARFI) is a new ultrasound technique that evaluates mechanical properties of tissues. To evaluate the use of ARFI with shear waves speed quantification for pancreatic masses characterization during the ultrasound examination.
  
  
  METHODS
  123 pancreatic lesions were prospectively evaluated. Median shear waves speeds were compared with Mann-Whitney U test. Two reading methods were applied for the characterization of adenocarcinoma: more than one measurement above the top shear waves speed (SWS) value. Two reading methods were applied to diagnose mucinous lesion: at least 2 (method 1) or 3 (method 2) numerical measurements. Sensitivity, specificity, positive and negative predictive values and accuracy of each reading method were calculated. Forty volunteers were included for normal ARFI values.
  
  
  RESULTS
  In the adenocarcinoma group median SWS value was 2.74 m/s. In the volunteers group the median SWS value was 1.17 m/s. Significant difference between SWS median values of adenocarcinoma and normal pancreas was found (P < 0.05). For the diagnosis of pancreatic solid masses if more than one measurement is above the top SWS value of 4.00 m/s results in the study, the diagnosis of ductal adenocarcinoma is highly specific with specificity and PPV of 100%. Good sensitivity (73.3%) and specificity (83.3%) were obtained for the characterization of mucinous cystic lesions.
  
  
  CONCLUSIONS
  Acoustic Radiation Force Impulse imaging could help in the non-invasive characterization of solid and cystic lesions of the pancreas during a conventional US examination.
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy. Electronic address: mirko.donforio@univr.it.
authors.forename: Mirko
authors.initials: M
authors.lastname: D'Onofrio
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: De Robertis
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Crosara
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Poli
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Canestrini
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Demozzi
authors.affiliation: Department of Radiology, G.B. Rossi Hospital, University of Verona, Piazzale L.A. Scuro 10, 37134 Verona, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pozzi Mucelli
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004338:Drug Combinations; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D005459:Fluorides; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D010710:Phosphates; D055815:Young Adult
chemical_list: D004338:Drug Combinations; D009566:Nitrates; D010710:Phosphates; C097427:Sensodyne; D005459:Fluorides
keywords: Acoustic Radiation Force Impulse (ARFI); Elastography; Pancreatic adenocarcinoma; Pancreatic cancer; Pancreatic cystic tumors; Ultrasonography