Objective To investigate the diagnostic value of calcification and cystic lesion of CT findings in differentiating pancreatic head ductal carcinoma (PHDA)from mass-forming chronic pancreatitis (MFCP)of the pancreatic head.Methods The clinic data and CT findings of 30 cases with PHDA and 24 cases with MFCP of the pancreatic head,which were confirmed by surgery and pathology were analyzed retrospectively.The images were reviewed independently by two expert radiologists with a double-blind method.An independent sample t test and chi-square test were used to compare the data of imaging findings between two groups.Results ① Calcification was found in 14 cases (58.33%)with MFCP and in 3 cases (10%)with PHDA (P＜0.001).The percentage of patchy,punctate and mixed calcification were 28.57% (n=4),14.29% (n=2)and 57.14% (n=8)in MFCP,0% (n=0),66.67% (n=2)and 33.33% (n=1) in PHDA,respectively.② Necrotic cyst was founded in 7 cases (29.17%)with MFCP and 18 cases (60%)with PHDA(P＜0.05). Pseudocysts were demonstrated in 14 cases (58.33%)with MFCP and in 3 cases (10%)with PHDA (P＜0.001).Honeycombed change with tension within or around the lesion were demonstrated only in patients with MFCP.In addition,normal tissue of the pancreas was found within the lesion in 11 cases (45.83%)of MFCP and none in PHDA,which showed significant difference between two groups.Conclusion Mixed calcification and honeycomb with tension of CT findings are of significant value in differentiating PHDA from MFCP of the pancreatic head.

Objective To evaluate CT vs.MRI in the intrapancreatic and relevant extrapancreatic findings of acute pancreatitis (AP).Methods The clinical data and image findings of 52 AP cases from Jan 2015 to Jun 2017 were analyzed retrospectively.Results CT is comparable to MRI in the diagnostic value of pancreatic enlargement and pancreatic necrosis (all P ＞ 0.05).Compared to CT,MRIwas superior in detecting the peripancreatic exudes,thickening of renal fascia,pleural effusion and abdominal wall edema (all P ＜ 0.01).In favor of MRI,there was significant difference in detection of gallbladder stones and choledocholithiasis,and hepatic swelling,hepatic fatty infiltration.Conclusions Both CT and MRI are significantly helpful to the early precise diagnosis of AP,while MRIis superior in showing etiology,pancreatic hemorrhage and necrosis,extrapancreatic lesions.