title: Contrast enhanced transabdominal ultrasound in the characterisation of pancreatic lesions with cystic appearance.
abstract: BACKGROUND
  Contrast enhanced ultrasound (CEUS) has been established for detection and characterisation of liver tumours and differential diagnosis of solid pancreatic lesions. The role of transabdominal CEUS in cystic pancreatic disease is less obvious.
  
  
  OBJECTIVE
  We prospectively evaluated CEUS for characterization of undetermined cystic pancreatic lesions with respect to the differential diagnosis of pseudocysts and cystic neoplasia and differentiation between benign and malignant disease (gold standard: histology or cytology).
  
  
  METHODS
  One-hundred and fourteen patients (63 males, 51 females; median age: 62 years, range: 33-87 years) were prospectively examined.
  
  
  METHODS
  Conventional B-mode and transabdominal CEUS.
  
  
  METHODS
  Conventional B-mode (criteria: solid nodules, septae), and contrast enhancing features of cystic pancreatic lesions (microperfusion of solid nodules) were analysed. Final diagnoses were made by surgery (47 patients) or histology/cytology and follow-up of at least one year (67 patients).
  
  
  RESULTS
  Fifty patients proved to have neoplastic lesions (37 malignant, 13 of benign origin). Sixty-four patients had pseudocysts caused by acute (27 patients) or chronic pancreatitis (37 patients). Conventional B-mode had a sensitivity of 94% and a low specificity of 44% in the differentiation of pseudocysts versus neoplasia. CEUS had a higher specificity of 77% with the same sensitivity of conventional B-mode ultrasound. The combination of conventional ultrasound and CEUS improved the specificity even more to 97% with an unchanged sensitivity. CEUS was not reliable in the differentiation of benign and malignant neoplasia.
  
  
  CONCLUSIONS
  CEUS improves the differentiation between pseudocysts and pancreatic neoplasia in comparison to the conventional B-mode imaging. The microvascularisation visualised using CEUS even in small nodules (with or without septae) associated with cystic lesions is an indicator for cystic pancreatic neoplasia.
authors.affiliation: Medical and Imaging Department, Caritas-Krankenhaus, Bad Mergentheim, Germany. christoph.dietrich@ckbm.de
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Beyer-Enke
authors.forename: Michael
authors.initials: M
authors.lastname: Hocke
authors.forename: Andre
authors.initials: A
authors.lastname: Ignee
authors.forename: Barbara
authors.initials: B
authors.lastname: Braden
authors.forename: Christoph F
authors.initials: CF
authors.lastname: Dietrich
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging*; D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008113:Liver Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014463:Ultrasonography
chemical_list: D003287:Contrast Media