title: Endocrine pancreatic tumours: which are the most useful MRI sequences?
abstract: OBJECTIVE
  To determine magnetic resonance imaging (MRI) signal and enhancement characteristics of endocrine pancreatic tumours (ETPs) and which MR sequences show them most consistently.
  
  
  METHODS
  Fifty-five consecutive patients with 68 ETPs underwent 1.5-T abdominal MRI comprising T2-weighted, unenhanced T1-weighted and dynamic T1-weighted after injection of gadopentetate dimeglumine sequences. Twenty-one patients underwent diffusion-weighted imaging (DWI). Two radiologists identified the number, location, size, signal and enhancement patterns of ETPs, and determined a confidence scale indicating the presence of tumours on DWI. The results were compared with echo-endoscopy (endoscopic ultrasound) findings.
  
  
  RESULTS
  The detection sensitivity was 95%, similar to that of echo-endoscopy. T2-weighted and T1-weighted sequences at the arterial phase had the highest contrast-to-noise ratio (CNR) median value. On DWI, the mean sensitivity was 65%. The mean apparent diffusion coefficient (ADC) value of ETP was significantly lower than in the normal parenchyma.
  
  
  CONCLUSIONS
  In suspected ETP, MRI is a sensitive method, similar to echo-endoscopy and could be recommended as the first imaging technique. T2-weighted sequences and T1-weighted sequences in the arterial phase are the optimal pulse sequences. The quantitative assessment of ADC values is a promising tool for the characterisation of pancreatic lesions.
authors.affiliation: Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805, Villejuif Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Caramella
authors.forename: C
authors.initials: C
authors.lastname: Dromain
authors.forename: T
authors.initials: T
authors.lastname: De Baere
authors.forename: B
authors.initials: B
authors.lastname: Boulet
authors.forename: M
authors.initials: M
authors.lastname: Schlumberger
authors.forename: M
authors.initials: M
authors.lastname: Ducreux
authors.forename: E
authors.initials: E
authors.lastname: Baudin
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D019160:Endosonography; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA