5.3　Classical Classification byERCP

Since the lesion of pancreatic duct is a typical feature of CP，there have been several theories aimed at classifying ductal changes via ERCP，of which the Cambridge Classification and the Morphologic Classification by Cremer et al.are generally accepted.

5.3.1　Cambridge Classification

The Cambridge Classification is the most widely used system for evaluating the severity and distribution of ductal changes on pancreatograms performed by ERCP（Sarner and Cotton 1984；Axon et al.1984）.Severity is graded from normal or equivocal to mild，moderate，or marked changes，and distribution is classified into either local（head，body or tail）or diffuse changes.(https://www.daowen.com)

Abnormalities in three or more side branches with a normal main pancreatic duct（MPD）are considered as mild changes.When the MPD is also abnormal，moderate changes could be diagnosed.Marked changes are confirmed by the presence of both three or more abnormal side branches and abnormal MPD with one or more additional features（large cavity，duct stricture or obstruction，severe duct dilatation or irregularity，or intraductal filling defects）.Besides the severity，changes should also be categorized into local or diffuse according to the proportion of pathological areas.

5.3.2　Morphologic Classification

The location and range of the pathological lesions caused by CP vary greatly from individual to individual；thus a morphologic classification was proposed by Cremer et al.（1989）based on the pancreatograms（Table 7.5）.The morphologic changes of CP are divided into four types，namely minor pancreatitis，focal pancreatitis，diffuse pancreatitis and segmental obstructive pancreatitis（Fig.7.15）.Each type has its own characteristic when pancreatography is carried out.