title: Gadolinium- and superparamagnetic-iron-oxide-enhanced MR findings of intrapancreatic accessory spleen in five patients.
abstract: OBJECTIVE
  The purposes of this study were to describe dynamic gadolinium-enhanced magnetic resonance imaging (MRI) findings of intrapancreatic accessory spleen(s) (IPAS) in five patients and to show how superparamagnetic iron oxide (SPIO) enhancement can be used for definite characterization in two cases.
  
  
  METHODS
  An MRI database was searched for patients who had pancreatic tail lesions with imaging features compatible with IPAS between June 2005 and July 2007. Five (four male, one female) patients (age: mean+/-S.D., 58+/-9.8 years; range, 50-75 years) were identified. All patients were examined with standard gadolinium-enhanced MRI protocol. Additionally, two patients were examined with SPIO-enhanced MRI protocol. All MRI examinations were retrospectively and blindly evaluated by two radiologists for the predetermined findings, and their final diagnoses were noted.
  
  
  RESULTS
  One pancreatic tail lesion was detected in each patient. All of these lesions were single, focal, well-marginated and located within 3 cm of the distal tail of the pancreas. The mean size (mean+/-S.D.) of the lesions was (2.02+/-0.64)x(1.72+/-0.42) cm2, and all lesions had a rounded morphology. The signal intensity of all lesions was similar to that of the spleen on all sequences, including precontrast, postgadolinium and post-SPIO sequences. The reviewers confidently diagnosed IPAS in two patients who had SPIO-enhanced MRI. In the remaining three patients, the reviewers favored the diagnosis of IPAS based on the findings of standard gadolinium-enhanced MRI; however, they could not definitively exclude the other differential diagnoses.
  
  
  CONCLUSIONS
  The discovery of a well-marginated, rounded mass in the distal aspect of the tail of the pancreas with signal intensity features of the spleen on all precontrast and postgadolinium sequences suggests the diagnosis of IPAS. However, SPIO-enhanced MRI can be used to characterize the lesion and to establish the definite diagnosis of IPAS in case of clinical doubt.
authors.affiliation: Department of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7510, USA.
authors.forename: Vasco
authors.initials: V
authors.lastname: Herédia
authors.forename: Ersan
authors.initials: E
authors.lastname: Altun
authors.forename: Fatmir
authors.initials: F
authors.lastname: Bilaj
authors.forename: Miguel
authors.initials: M
authors.lastname: Ramalho
authors.forename: Brian W
authors.initials: BW
authors.lastname: Hyslop
authors.forename: Richard C
authors.initials: RC
authors.lastname: Semelka
mesh_terms: D000368:Aged; D002828:Choristoma / Q000175:diagnosis*; D003287:Contrast Media; D003911:Dextrans; D005260:Female; D052203:Ferrosoferric Oxide; D019786:Gadolinium DTPA; D006801:Humans; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds; D010087:Oxides; D010182:Pancreatic Diseases / Q000175:diagnosis*; D012189:Retrospective Studies; D013154:Spleen
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D009942:Organometallic Compounds; D010087:Oxides; C064572:gadobenic acid; D008536:Meglumine; C064925:gadodiamide; D007501:Iron; C065507:ferumoxides; D019786:Gadolinium DTPA; D052203:Ferrosoferric Oxide