Background: 

The aim was to compare the differences of clinical-radiologic characteristics between malignant and benign causes of patients with unexplained distal obstructive biliary dilatation and to develop a logistic regression model (nomogram) based on those features to predict malignant causes preoperatively.

Patients and Methods: 

Clinical-radiologic characteristics of 133 patients with unexplained distal obstructive biliary dilatation were analyzed. Multivariate logistic regression analysis was performed to construct a nomogram to predict malignant causes preoperatively. The developed nomograms were externally validated by assessing their predictive accuracy in an independent set of 90 patients.

Results: 

Intrahepatic bile duct diameter, enlarged gallbladder, direct bilirubin, and carbohydrate antigen19-9 differed significantly between malignant and benign group. In the training set, the logistic regression model showed the discrimination between benign and malignant causes of distal obstructive biliary dilatation with an area under the curve of 0.965, an accuracy of 0.904, a sensitivity of 0.886, a specificity of 0.913. In the validation set, the model showed an area under the curve of 0.851, an accuracy of 0.837, a sensitivity of 0.897, a specificity of 0.750.

Conclusions: 

Preoperative clinical-radiologic characteristics differed significantly between malignant and benign group. Nomogram based on those features performed well in predicting the malignant causes of patients with unexplained distal obstructive biliary dilatation.

中文翻译：

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不明原因的远端梗阻性胆管扩张：基于磁共振胰胆管造影 (MRCP) 的模型区分恶性与良性起源

背景： 

目的是比较不明原因远端梗阻性胆管扩张患者恶性和良性病因之间的临床放射学特征差异，并根据这些特征开发逻辑回归模型（列线图）以在术前预测恶性病因。

患者和方法： 

对 133 例不明原因的远端梗阻性胆管扩张患者的临床放射学特征进行了分析。进行多变量逻辑回归分析以构建列线图来预测术前的恶性原因。通过评估 90 名独立患者的预测准确性，对开发的列线图进行了外部验证。

结果： 

恶性组和良性组的肝内胆管直径、胆囊肿大、直接胆红素和糖抗原19-9有显着差异。在训练集中，逻辑回归模型显示了远端梗阻性胆道扩张良恶性病因的区分，曲线下面积为0.965，准确度为0.904，敏感性为0.886，特异性为0.913。在验证集中，模型的曲线下面积为 0.851，准确度为 0.837，敏感性为 0.897，特异性为 0.750。

结论： 

恶性组和良性组的术前临床放射学特征存在显着差异。基于这些特征的列线图在预测不明原因远端梗阻性胆管扩张患者的恶性原因方面表现良好。