title: Quantitative analysis of diffusion-weighted magnetic resonance imaging of the pancreas: usefulness in characterizing solid pancreatic masses.
abstract: OBJECTIVE
  To evaluate whether measurement of apparent diffusion coefficient (ADC) and pure diffusion coefficient (D) can help to characterize solid pancreatic masses.
  
  
  METHODS
  Diffusion-weighted MR imaging was performed in both a patient group (n = 71; pancreatic cancer [n = 47], mass-forming pancreatitis [n = 13], solid pseudopapillary neoplasm [n = 6], and neuroendocrine tumor [n = 5]) and a normal control group (n = 11) by applying three b-factors of 0, 500, and 1000 sec/mm(2). ADC(500), ADC(1000), D (ADC using b = 500 and 1000 sec/mm(2)), and perfusion fraction (f, 1- exp [-500 sec/mm(2) x (ADC(500) - D)]) of normal pancreas, pancreatic cancer, and mass-forming pancreatitis were compared using the Kruskal-Wallis test. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance and optimal cutoff value of these parameters in differentiating pancreatic cancer from mass-forming pancreatitis.
  
  
  RESULTS
  Normal pancreas had significantly higher mean ADC(500), ADC(1000), and f than either pancreatic cancer (P < 0.001, < 0.001, and 0.004, respectively) or mass-forming pancreatitis (P < 0.001, < 0.001, and 0.002, respectively). ADC(500), ADC(1000), and D of mass-forming pancreatitis were significantly lower than those of pancreatic cancer (P = 0.002, 0.004, and 0.014, respectively). Sensitivities and specificities in the diagnosis of pancreatic cancer were 72.3% and 76.9% for ADC(500), 87.2% and 69.2% for ADC(1000), 87.2% and 61.5% for D, and 42.6% and 92.3% for f, respectively.
  
  
  CONCLUSIONS
  Measurement of ADC and D may be helpful in differentiating pancreatic cancers from mass-forming pancreatitis.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Seung Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Byun
authors.forename: Beom Jin
authors.initials: BJ
authors.lastname: Park
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Park
authors.forename: Namkug
authors.initials: N
authors.lastname: Kim
authors.forename: Bumwoo
authors.initials: B
authors.lastname: Park
authors.forename: Jeong Kon
authors.initials: JK
authors.lastname: Kim
authors.forename: Moon-Gyu
authors.initials: MG
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D010195:Pancreatitis / Q000175:diagnosis* / Q000473:pathology; D012372:ROC Curve