title: Incidental pancreatic cysts: natural history and diagnostic accuracy of a limited serial pancreatic cyst MRI protocol.
abstract: OBJECTIVE
  To examine the natural history of incidentally detected pancreatic cysts and whether a simplified MRI protocol without gadolinium is adequate for lesion follow-up.
  
  
  METHODS
  Over a 10-year period, 301-patients with asymptomatic pancreatic cysts underwent follow-up (45 months ± 30). The magnetic resonance imaging (MRI) protocol included axial, coronal T2-weighted images, MR cholangiopancreatographic and fat suppressed T1-weighted sequences before and after gadolinium. Three radiologists independently reviewed the initial MRI, the follow-up studies using first only unenhanced images, then secondly gadolinium-enhanced-sequences. Lesion changes during follow-up were recorded and the added value of gadolinium-enhanced sequences was determined by classifying the lesions into risk categories.
  
  
  RESULTS
  Three hundred and one patients (1,174 cysts) constituted the study population. Only 35/301 patients (12 %) showed significant lesion change on follow-up. Using multivariate analysis the only independent factor of lesion growth (OR = 2.4; 95 % CI, 1.7-3.3; P < 0.001) and mural nodule development (OR = 1.9; 95 % CI, 1.1-3.4, P = 0.03) during follow-up was initial lesion size. No patient with a lesion initial size less than 2 cm developed cancer during follow-up. Intra-observer agreement with and without gadolinium enhancement ranged from 0.86 to 0.97. After consensus review of discordant cases, gadolinium-enhanced sequences demonstrated no added value.
  
  
  CONCLUSIONS
  Most incidental pancreatic cystic lesions did not demonstrate change during follow-up. The addition of gadolinium-enhanced-sequences had no added-value for risk assignment on serial follow-up.
  
  
  CONCLUSIONS
  Significant growth of pancreatic cysts occurred in a minority of patients only. No lesion <2 cm demonstrated any change during the first year of follow-up. Intra-observer agreement between MR pancreatic protocols with and without gadolinium was excellent. Gadolinium application had limited value for follow-up of asymptomatic pancreatic cystic lesions.
authors.affiliation: Department of Abdominal Imaging, Saint Eloi University Hospital, 80 avenue Augustin Fliche, 34295, Montpellier Cedex 5, France, stephanienougaret@free.fr.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Nougaret
authors.forename: Caroline
authors.initials: C
authors.lastname: Reinhold
authors.forename: Jaron
authors.initials: J
authors.lastname: Chong
authors.forename: Laure
authors.initials: L
authors.lastname: Escal
authors.forename: Gregoire
authors.initials: G
authors.lastname: Mercier
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Fabre
authors.forename: Boris
authors.initials: B
authors.lastname: Guiu
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molinari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000175:diagnosis*; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA