1.2　The Cambridge Classification

The Cambridge classification established distinct criteria in which it described equivocal，mild，moderate，and severe changes by imaging with ERCP（Sarner and Cotton 1984a，b；Axon et al.1984）.The Cambridge classification also categorized pancreatic imaging findings on CT and abdominal US just like the grading of ERCP changes（Sarner and Cotton 1984a，b；Axon et al.1984）.However，the grading according to CT and US had difficulty in distinguishing between mild and moderate changes.Since the early 1980s，EUS has been widely used in the diagnosis of CP and pancreatic cancer.Thus，it has detected several characteristic findings which were described in details（Wiersema et al.1993；Catalano et al.1998；Sahai et al.1998；Kahl and Malfertheiner 2005；Nattermann et al.1993）.According to the Cambridge classification，the suggestions for using various imaging means to grade morphological changes are summarized.(https://www.daowen.com)