title: Characterization of focal pancreatic lesions using normalized apparent diffusion coefficient at 1.5-Tesla: preliminary experience.
abstract: OBJECTIVE
  To compare the capabilities of apparent diffusion coefficient (ADC) and normalized ADC using the pancreatic parenchyma as reference organ in the characterization of focal pancreatic lesions.
  
  
  METHODS
  Thirty-six patients with focal pancreatic lesions (malignant, n=18; benign tumors, n=10; focal pancreatitis, n=8) underwent diffusion-weighted MR imaging (DWI) at 1.5-Tesla using 3 b values (b=0, 400, 800 s/mm(2)). Lesion ADC and normalized lesion ADC (defined as the ratio of lesion ADC to apparently normal adjacent pancreas) were compared between lesion types using nonparametric tests.
  
  
  RESULTS
  Significant differences in ADC values were found between malignant (1.150 × 10(-3)mm(2)/s) and benign tumors (2.493 × 10(-3)mm(2)/s) (P=0.004) and between benign tumors and mass-forming pancreatitis (1.160 × 10(-3)mm(2)/s) (P=0.0005) but not between malignant tumors and mass-forming pancreatitis (P=0.1092). Using normalized ADC, significant differences were found between malignant tumors (0.933 × 10(-3)mm(2)/s), benign tumors (1.807 × 10(-3)mm(2)/s) and mass-forming pancreatitis (0.839 × 10(-3)mm(2)/s) (P<0.0001).
  
  
  CONCLUSIONS
  Our preliminary results suggest that normalizing ADC of focal pancreatic lesions with ADC of apparently normal adjacent pancreatic parenchyma provides higher degrees of characterization of focal pancreatic lesions than the conventional ADC does.
authors.affiliation: Department of Abdominal Imaging, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, 2 rue Ambroise-Paré, 75010 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Barral
authors.forename: D
authors.initials: D
authors.lastname: Sebbag-Sfez
authors.forename: C
authors.initials: C
authors.lastname: Hoeffel
authors.forename: U
authors.initials: U
authors.lastname: Chaput
authors.forename: A
authors.initials: A
authors.lastname: Dohan
authors.forename: C
authors.initials: C
authors.lastname: Eveno
authors.forename: M
authors.initials: M
authors.lastname: Boudiaf
authors.forename: P
authors.initials: P
authors.lastname: Soyer
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018291:Cystadenoma, Mucinous / Q000175:diagnosis; D018293:Cystadenoma, Serous / Q000175:diagnosis; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000175:diagnosis; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D050500:Pancreatitis, Chronic / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D055815:Young Adult