Quantitative analysis of calcification and cystic degeneration in differentiating mass-forming chronic pancreatitis from pancreatic ductal adenocarcinoma

XIA Xiaomei; RUAN Zhibing; CHEN Huilin; WEN Feng; CHEN Kun; SHI Shihan

Abstract：Objective To quantitatively analyze the calcification and cystic changes in the mass,and to explore the value of quantitative index calcification volume and subjective evaluation of calcification and cystic CT signs in the differential diagnosis of mass-forming chronic pancreatitis(MFCP)and pancreatic ductal adenocarcinoma(PDAC)and the difference in diagnostic efficacy.Methods The clinical and CT data of 103 patients with MFCP and 188 patients with PDAC were collected,and the CT signs of calcification and cystic degeneration in the mass were analyzed.Based on the software quantitative analysis technol-ogy,the calcification volume in the mass was extracted and the maximum cyst diameter was measured.The data of the two groups were statistically analyzed.The ROC curve was used to evaluate the diagnostic efficacy of the incidence of calcification,the inci-dence of cystic degeneration and the volume of calcification in differentiating MFCP from PDAC.Results 1)Mass calcifica-tion:The incidence of calcification in the MFCP group and the PDAC group was 54.4％and 10.1％,respectively,and the dif-ference was statistically significant(P＜0.001).The MFCP group was dominated by mixed calcification,multiple and diffuse distribution,and the PDAC group was dominated by a few spotted,nodular calcification and central distribution.The calcifica-tion volume(cm3)Median(IQR)was 1.16(0.55,2.54)and 0.12(0.06,0.24),respectively,and the difference was statisti-cally significant(P<0.001).2)Cystic lesions:The incidence of cystic lesions in MFCP group and PDAC group was 77.7％and 48.9％,respectively,and the difference was statistically significant(P<0.001).Among them,honeycomb cysts were only found in the MFCP group,with an incidence of 16.5％.The cystic lesions in the MFCP group were full of tension,and 18 cases of cys-tic wall calcification.The cystic lesions in the PDAC group showed various forms(24 cases of cystic solid and 5 cases of simple cystic lesions),and 1 case of cystic wall calcification.There was no significant difference in the incidence of multiple cysts and the maximum cyst diameter between the two groups(P＞0.05).3)ROC evaluation:The AUC values of calcification incidence,cystic degeneration incidence and calcification volume in the two groups were 0.726,0.664 and 0.876,respectively.The optimal cutoff value of calcification volume was 0.32cm3.When the calcification volume was＞0.32cm3,it was suggested to be MFCP.Conclusion The CT signs of calcification and cystic degeneration are helpful for the differential diagnosis of MFCP and PDAC.The quantitative index calcification volume has better differential diagnosis efficiency.Multiple,diffusely distributed mixed calci-fication and full honeycomb cystic lesions with tension are helpful for the diagnosis of MFCP.MFCP is indicated when the calcifi-cation volume＞0.32 cm3.