title: Acoustic radiation force impulse shear wave elastography (ARFI) of acute and chronic pancreatitis and pancreatic tumor.
abstract: BACKGROUND
  Acoustic Radiation Force Impulse (ARFI) elastography evaluates tissue stiffness non-invasively and has rarely been applied to pancreas examinations so far. In a prospective and retrospective analysis, ARFI shear wave velocities of healthy parenchyma, pancreatic lipomatosis, acute and chronic pancreatitis, adenocarcinoma and neuroendocrine tumor (NET) of the pancreas were evaluated and compared.
  
  
  METHODS
  In 95 patients ARFI elastography of the pancreatic head, and also of the tail for a specific group, was analysed retrospectively. Additionally, prospectively in 100 patients ARFI was performed in the head and tail of the pancreas.
  
  
  RESULTS
  A total of 195 patients were included in the study. Healthy parenchyma (n=21) and lipomatosis (n=30) showed similar shear wave velocities of about 1.3m/s. Acute pancreatitis (n=35), chronic pancreatitis (n=53) and adenocarcinoma (n=52) showed consecutively increasing ARFI values, respectively. NET (n=4) revealed the highest shear wave velocities amounting to 3.62m/s. ARFI elastography showed relevant differences between acute pancreatitis and chronic pancreatitis or adenocarcinoma. With a cut-off value of 1.74m/s for the diagnosis of a malignant disease the sensitivity was 91.1% whereas the specificity amounted to 60.4%.
  
  
  CONCLUSIONS
  ARFI shear wave velocities present differences in various pathologies of the pancreas. Acute and chronic pancreatitis as well as neoplastic lesions show high ARFI values. Very high elasticity values may indicate malignant disease of the pancreas. However, there is a considerable overlap between the entities.
authors.affiliation: Department of Internal Medicine 1, University Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen, Germany. Electronic address: ruediger.goertz@uk-erlangen.de.
authors.forename: Ruediger S
authors.initials: RS
authors.lastname: Goertz
authors.affiliation: Department of Internal Medicine 1, University Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen, Germany. Electronic address: Johanna@schuderer-floss.de.
authors.forename: Johanna
authors.initials: J
authors.lastname: Schuderer
authors.affiliation: Department of Internal Medicine 1, University Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen, Germany. Electronic address: deike.strobel@uk-erlangen.de.
authors.forename: Deike
authors.initials: D
authors.lastname: Strobel
authors.affiliation: Department of Internal Medicine 1, University Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen, Germany. Electronic address: Lukas.Pfeifer@uk-erlangen.de.
authors.forename: Lukas
authors.initials: L
authors.lastname: Pfeifer
authors.affiliation: Department of Internal Medicine 1, University Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen, Germany. Electronic address: Markus.Neurath@uk-erlangen.de.
authors.forename: Markus F
authors.initials: MF
authors.lastname: Neurath
authors.affiliation: Department of Internal Medicine 1, University Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen, Germany. Electronic address: Dane.Wildner@uk-erlangen.de.
authors.forename: Dane
authors.initials: D
authors.lastname: Wildner
mesh_terms: D000208:Acute Disease; D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008068:Lipomatosis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging; D010179:Pancreas / Q000000981:diagnostic imaging; D010182:Pancreatic Diseases / Q000000981:diagnostic imaging; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D010195:Pancreatitis / Q000000981:diagnostic imaging*; D050500:Pancreatitis, Chronic / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: ARFI; Carcinoma; Elastography; Pancreas; Pancreatitis