title: Intravoxel incoherent motion MRI for the differentiation between mass forming chronic pancreatitis and pancreatic carcinoma.
abstract: OBJECTIVE
  To determine which of the quantitative parameters obtained from intravoxel incoherent motion diffusion weighted imaging (DWI) is the most significant for the differentiation between pancreatic carcinoma and mass-forming chronic pancreatitis.
  
  
  METHODS
  Twenty-nine patients with pancreatic masses were included, 9 proved to have a mass-forming pancreatitis and 20 had a pancreatic carcinoma. The patients were studied using intravoxel incoherent motion DWI with 11 b-values and the apparent diffusion coefficient (ADC), the true diffusion constant (D) and the perfusion fraction (f) were calculated. The diagnostic strength of the parameters was evaluated using receiver operating characteristic analysis.
  
  
  RESULTS
  The ADC in chronic pancreatitis was higher than in pancreatic carcinoma with significant differences at b = 50, 75, 100, 150, 200, 300 s/mm (ADC50 = 3.17 ± 0.67 vs. 2.55 ± 1.09, ADC75 = 2.46 ± 0.4 vs. 1.93 ± 0.52, ADC100 = 2.28 ± 0.48 vs. 1.73 ± 0.45, ADC150 = 1.97 ± 0.26 vs. 1.63 ± 0.40, ADC200 = 1.98 ± 0.24 vs. 1.53 ± 0.28, and ADC300 = 1.76 ± 0.19 vs. 1.46 ± 0.31 × 10(-3) mm2/s). No significant differences were found at b = 25, 400, 600, and 800 s/mm (ADC25 = 4.69 ± 0.65 vs. 4.04 ± 1.35, ADC400 = 1.57 ± 0.21 vs. 1.37 ± 0.30, ADC600 = 1.38 ± 0.18 vs. 1.24 ± 0.25, and ADC800 = 1.27 ± 0.10 vs. 1.18 ± 0.19 × 10(-3) mm2/s) nor using ADCtot (1.42 ± 0.23 vs. 1.28 ± 0.12 × 10(-3) mm2/s). The perfusion fraction f was significantly higher in pancreatitis compared with pancreatic carcinoma (16.3% ± 5.30% vs. 8.2% ± 4.00%, P = 0.0001). There was no significant difference between groups for D (1.07 ± 0.224 × 10(-3) mm2/s for chronic pancreatitis and 1.09 ± 0.3 × 10(-3) mm2/s for pancreatic carcinoma, P = 0.66). For f, the highest area under the curve (0.894) and combined sensitivity (80%) and specificity (89.9%) were found.
  
  
  CONCLUSIONS
  There were significant differences in ADC50-300 between chronic pancreatitis and pancreatic carcinoma. Because D is not significantly different between groups, differences in ADC can be attributed mainly to differences in perfusion. The perfusion fraction f proved to be the superior DWI-derived parameter for differentiation of mass-forming pancreatitis and pancreatic carcinoma.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Klauss
authors.forename: Andreas
authors.initials: A
authors.lastname: Lemke
authors.forename: Katharina
authors.initials: K
authors.lastname: Grünberg
authors.forename: Dirk
authors.initials: D
authors.lastname: Simon
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Re
authors.forename: Mortiz N
authors.initials: MN
authors.lastname: Wente
authors.forename: Frederik B
authors.initials: FB
authors.lastname: Laun
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Stefan
authors.initials: S
authors.lastname: Delorme
authors.forename: Lars
authors.initials: L
authors.lastname: Grenacher
authors.forename: Bram
authors.initials: B
authors.lastname: Stieltjes
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology*; D050500:Pancreatitis, Chronic / Q000175:diagnosis* / Q000473:pathology; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012984:Software; D013223:Statistics as Topic