ABSTRACT
Objective To value the capability of MRI in assessing invasiveness of intraductal papillary neoplasms of the bile duct(IPNB). Methods Thirty-nine patients with pathologically confirmed IPNB, who had upper abdominal MR examination within 6 weeks before complete resection of the tumor, were included in the retrospective study. Patients were divided into noninvasive and invasive groups pathologically. Eighteen cases were noninvasive and 21 were invasive. All had undergone MRI plain scans, MR cholangiopancreatography as well as contrast enhanced scans including arterial, portal and delayed phases. Tumor size, location, biliary dilation, thread signs, lesion morphology, lobe atrophy, cholelithiasis, biliary hemorrhage, vascular invasion and intraperitoneal lymphadenopathy were observed on MRI. ADC values and enhancement level of lesions were also measured. Between invasive and noninvasive groups, laboratory results, enhancement levels and ADC values were compared by t test or Mann-Whitney U test, and categorical variables like location and lesion morphology were compared by χ2 test. The diagnostic accuracy was calculated using receiver operating characteristic(ROC)curve analysis. Results No difference was found between invasive and noninvasive groups on gender, age, lesion morphology, bile duct diameter, location, existence of thread signs or cholelithiasis(P>0.05). While the differences on serum CA19-9 level, lesion size, ADC value, and lymph nodes/vascular invasion between groups reached statistical significance (P0.05), CNR and enhancement levels were also statistically different on arterial, portal and delayed phases between both groups(P<0.05). CA199, enhancement level and CNR of portal phase, as well as ADC value exhibited areas under the ROC curve(AUC)of 0.790, 0.891, 0.817 and 0.882 respectively in invasiveness judgment. Conclusion MR demonstrated relatively high value in assessing invasiveness of IPNB.