MRCP Study Of Pancreaticobiliary Maljunction And Pancreaticobiliary Diseases

Background and ObjectivePancreaticobiliary maljunction is characterized as congenital anomaly in which thepancreatic and biliary ducts are joined outside the duodenal wall and forms a longcommon channel and therefore not under the influence of the sphincter of Oddi.Alternatively consider as the biliary duct and pancreatic ducts not convergence,respectively, into the duodenal wall. The confluence of this anatomical abnormality isclosely related to the occurrence of pancreatic biliary diseases.Early studies of the anatomy on the confluence of the pancreatic duct are mainlyperformed on the basis of the autopsy, or endoscopic retrogradecholangiopancreatography (ERCP), which is an invasive study. With the rapiddevelopment of spiral CT equipment and the image processing technology nowadays,the pancreatic duct confluence and adjacent anatomy of the abdominal viscera are ableto be displayed clearly. This vivo and noninvasive examination provides hugeconvenience for the diagnosis of the pancreatic biliary disease. However, the use of CTscan has its own limitations. In addition to the risk of radiation damage, patients withallergic tendencies to the agent and obstructive jaundice as well as high blood bilirubinare not advised to perform an enhanced CT scan. In contrast to CT scan, magneticresonance cholangiopancreatography (MRCP) is able to obtain the anatomical andpathological changes of the pancreatic duct without contrast agent. The use of theMRCP effectively compensates the defects of the ERCP and CT examination. This study aimed to explore the type of the cholangiopancreatography convergence sub andthe incidence of abnormal confluence with pancreatic biliary disease by analyse bothMRI images and clinical data on the basis of the MRCP vivisection. Our study is todiscuss the imaging anatomy about the convergence of the pancreaticobiliary duct,types of the Pancreaticobiliary maljunction (PBM) and associated diseases in Chinesepopulation by using magnetic resonance cholangiopancreatography (MRCP)examination.Materials and MethodsData were collected from963patients that performed with MRCPs from January2010to December2011. All cases were examined by single shot FSE sequence(fastspin-echo). The maximum intensity projection (MIP) were used in order to obtainMRCP images.ResultsWe analyzed the anatomy of pancreaticobiliary junction based on MRCP images, andthen classified the types of the pancreaticobiliary junction to normal type and abnormaltype. The mode of Abnormal type can be further divided into P-B type, where the mainpancreatic duct enters the common bile duct; B-P type, where the common bile ductenters the pancreatic duct; and the duodenum type. We analyzed the incidence of thepancreatitis、malignancy of biliary tree as well as pancreatic carcinoma between normaland abnormal group and found significant differences (P<0.05). Abnormal group ismore likely to suffer from pancreaticobiliary dieseases. We compared different types ofPBM that associated with the pancreaticobiliary diseases by using fisher’s method andshows there are no significant differences between biliary stone、cholecystitis and pancreatic carcinoma (P>0.05)，pancreatitis in B-P type and P-B type are higher than inthe duodenum type (P<0.05)，malignancy of biliary tree in B-P type are more than inP-B type whereas the malignancy of biliary tree in the duodenum type are less than inP-B type(P<0.05). The incidence of the congenital choledochal cyst in both normal typeand abnormal type are similar. There are no significant difference between twogroups(P>0.05).ConclusionsThe types of PBM are closely related to the occurrence of pancreaticobiliary diseases,particularly pancreatitis, tumor of biliary tree and pancreatic tumor. MRCP imaginescan be used in the diagnosis of the ancreaticobiliary diseases such as assisting to displaythe position of anormaly and to define different types of PBM. Early diagnosis andprevention treatment will be made based on MRCP imagines.