Study The Value Of IVIM And DKI In Differentiating Pancreatic Cancer From Chronic Mass-forming Type Pancreatitis

Purpose: Preliminary evaluation the clinical application value of theparameters of IVIM and DKI in differential diagnosis of pancreaticcancer and chronic mass type pancreatitis.Marerials and Methods:14patients with pancreatic cancer, whichwas confirmed by pathology, and9patients with chronic pancreatitis inwhich3was confirmed by pathology and6was confirmed by clinicalfollow-up were chosen in this study from July2013to March2014.All patients underwent pancreas MR imaging with a3-T systemPhilips by using a breath phased-array coil (free breathing, supineposition). Pulse sequences included axial T2-weighted turbo spin-echoimaging, IVIM(b values of0,25,50,75,100,150,200,300,400,600,and800s/mm2),and DKI(b values of0,500,1000,1500,and2000s/mm2). All datawere postprocessed by post-processing software. D, f, D*were calculatedby IVIM-DWI, MD,MK were calculated by DKI, and ADC werecalculated by using b-value of600.Prameters derived from diseasedregion and normal tissue on the same patients were compared by analysisof variance. Operating characteristic curve analyses were conducted to assess and compare IVIM and DKI in terms of their diagnostic value.Result: f has statistically significant differences between pancreaticcancer,chronic pancreatitis,and normal pancreas.（8.36±2.34vs13.77±3.22vs25.1±5.8%，P<0.01p=0.00）；D*was lower than normalpancreas in pancreatic cancer and chronic pancreatitis（29±8.8/35±6.2vs57.1±7.8×10-3mm2/s，P＜0.05），but no statisticaldifference between pancreatic cancer and chronic pancreatitis.(P=0.100）；D was lower than the pancreatic cancer and normal pancreasin chronic pancreatitis（0.98±0.15vs1.26±0.19/1.32±0.17×10-3mm2/s，P＜0.05），But no statistical difference between pancreatic cancer andnormal pancrea（sP=0.413）；there were statistically significant differencesof MK between pancreatic cancer, chronic pancreatitis,and normalpancreas（0.90±0.056vs0.82±0.034vs0.66±0.15，p<0.01）, MD innormal pancreatic is significantly higher than pancreatic cancer andchronic pancreatitis（2.30±0.20vs2.06±0.12/2.02±0.13×10-3mm2/s，P＜0.05），But no statistical difference between pancreatic cancer and chronicpancreatitis（P=0.418）；ADC values in normal pancreas was significantlyhigher than that of pancreatic cancer and chronic pancreatitis（1.38±0.24vs1.09±0.19/1.11±0.16×10-3mm2/s，P＜0.01），But no statistical differencebetween pancreatic cancer and chronic pancreatitis（P=0.883）。The areaunder the curve of parameters f in IVIM and MK in DKI was0.92and0.86respectively,and there are no statistical difference between them (P=0.532）.Conclusion: f in pancreatic cancer was significantly higher, and MKwas significantly lower than that of chronic pancreatitis and normal pancreas.There are clinical application value of IVIM and DKI model in diagnosisand differential diagnosis of pancreatic cancer and chronic mass-formingtype pancreatitis.