CT analysis and differentiation of pancreatic carcinoma coexisting with chronic pancreatitis from chronic pancreatitis

Objective:To analyze CT characteristics of pancreatic carcinoma coexisting with chronic pancreatitis versus chronic pancreatitis in order to improve its CT differential diagnostic accuracy.Methods:CT findings in 14 cases of pancreatic carcinoma coexisting with chronic pancreatitis and 15 cases of chronic pancreatitis were retrospectively analyzed.Both plain and enhanced CT scans were performed in all cases.Thin-layer scan was practiced when required.Observation was focused on the size,shape,density of pancreas,its relationship with Peripancreatic tissues,the images of enhancement,and the location,size,density of pancreatic carcinoma.Moreover,observation was focused on the dilation of common bile duct,main pancreatic duct and hepatic bile duct Then,CT characteristics of pancreatic carcinoma coexisting with chronic pancreatitis and chronic pancreatitis were analyzed and compared.Results:In the pancreatic carcinoma coexisting with chronic pancreatitis group,all cases have mass,and noenhancement in the arterial phrase.Peripancreatic blood vessels were invaded or surrounded(5 cases and 4 cases respectively).Peripancreatic adipose were not seen enough(5 cases).Lymph node enlargement(4 cases),Liver metastasis(5 cases).Dilation of common bile duc(t8 cases,9.67 mm±2.64 mm),6 of which showed broke off abruptly.Pancreas atrophy(6 cases),Calcification(4 cases),Dilation of main pancreatic duc(t7 cases),Pseudocys(t2 cases).In chronic pancreatitis group,pancreatic mass(2 cases),one of which showed no enhancement in the arterial phrase;Peripancreatic blood vessels was surrounded by Peripancreatic mass and the boundary between blood vessels and adipose was not clear(1 case);None of the cases was seen Peripancreatic blood vessels invasion;no liver metastasis or Lymph node metastasis.Dilation of common bile duc(t3 cases,7.53 mm±1.45 mm),one of which showed broke off abruptly.Pancreas atrophy(7 cases),Calcification(5 cases),Dilation of main pancreatic duct(7 cases,4.73 mm±3.04 mm),Pseudocyst(4 cases).Conclusion:Style of mass dynamic enhancement of pancreatic carcinoma coexisting with chronic pancreatitis,Peripancreatic blood vessels invasion,liver metastasis,and lymph node metastasis are important basis of CT differentiation of pancreatic carcinoma coexisting with chronic pancreatitis from chronic pancreatitis.