title: Quantified ADC histogram analysis: a new method for differentiating mass-forming focal pancreatitis from pancreatic cancer.
abstract: BACKGROUND
  As their prognosis and management are different, differentiation of mass-forming focal pancreatitis (FP) from pancreatic adenocarcinoma (PC) is important. However, the similar clinical presentations and imaging features of these conditions, along with inconclusive biopsy results can make such differentiation difficult.
  
  
  OBJECTIVE
  To determine whether apparent diffusion coefficient (ADC) histogram analysis can discriminate between a normal pancreas, FP, and PC.
  
  
  METHODS
  In a retrospective study, 25 PC patients, 14 FP patients, and 25 subjects with a normal pancreas underwent breath-hold diffusion-weighted imaging (DWI) on a 3.0 T magnetic resonance (MR) scanner. Regions of interest (ROIs) were drawn on the normal pancreases and on the entire focal lesions of both PC and FP. The ADC value was averaged from the lowest to 10th, 30th, 50th, and 100th percentile of the histogram (i.e. ADC10, ADC30, ADC50, and ADC100, respectively), and the results were analyzed statistically.
  
  
  RESULTS
  There were no significant differences among the head, body, and tail of normal pancreases for any of the mean ADC values (P > 0.05). ADC10, ADC30, and ADC50 values demonstrated significant differences between lesion and non-lesion areas of both PC (P < 0.05) and FP (P < 0.05). Differences in lesion areas between PC and FP were found with ADC50 and ADC100 values (P < 0.05), and helped differentiate a normal pancreas from FP and PC, and FP from PC.
  
  
  CONCLUSIONS
  Quantified ADC histogram can specifically reflect tissue heterogeneity and help differentiate a normal pancreas from FP and PC.
authors.affiliation: Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Ma
authors.affiliation: Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China maxh19782006@sina.com.
authors.forename: Xinming
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Han
authors.initials: H
authors.lastname: Ouyang
authors.affiliation: GE Healthcare, Beijing, People's Republic of China.
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.affiliation: Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Chunwu
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003937:Diagnosis, Differential; 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; D009716:Numerical Analysis, Computer-Assisted; D015588:Observer Variation; D010190:Pancreatic Neoplasms / Q000473:pathology*; D010195:Pancreatitis / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Diffusion-weighted imaging; apparent diffusion coefficient; focal pancreatitis; histogram analysis; pancreatic adenocarcinoma