ABSTRACT
Purpose The diagnosis, treatment and prognosis of benign and malignant biliary stricture are significantly different. This study aims to evaluate the quantitative analysis of biliary structures using magnetic resonance cholangiopancreatography (MRCP) combined with dynamic contrast enhanced CT (DCE-CT).Materials and Methods The quantitative parameters of MRCP and DCE-CT imaging data from 27 patients with benign biliary stricture (benign group) and 30 patients with malignant biliary stricture (malignant group) were retrospectively analyzed. The wall thickness, stricture length and diameter, proximal ductal dilatation and degree of enhancement in two groups were compared, and its correlation was analyzed to evaluate the accuracy of MRCP and DCE-CT.Results There were significant differences in wall thickness [(3.2±2.0) mmvs (2.1±0.6) mm], stricture length [(15.8±8.1) mmvs (9.5±6.5) mm] and diameter [0 mmvs (2.0±0.9) mm], proximal ductal dilatation and the degree of enhancement [(12.7±3.6) mmvs (9.3±2.7) mm] between the two groups (t=2.825, 3.270, 4.025,P<0.001;Z=-3.909,P<0.001). Multivariable stepwise regression analysis showed that the wall thickness and diameter, and the CT HU in portal venous and equilibrium phases combined with CT plain scanning were significant predictors of malignant biliary strictures (t=-6.424-2.309,P<0.05). The sensitivity, specificity, inter-modality agreement and Youden index of MRCP and DCE-CT in diagnosing 57 patients with biliary stricture were 96.67%, 100.00%, 98.25% and 0.97, respectively; with statistical significance in predicting benign and malignant biliary stricture (AUC=0.994,P<0.001).Conclusion Using MRCP and DCE-CT, the wall thickness and diameter of the stricture, and the difference in CT HU in portal venous and equilibrium phases combined with CT plain scanning are valuable in differential diagnosis of benign and malignant biliary stricture.