探讨多层螺旋CT成像鉴别不同组织来源的恶性低位胆道梗阻疾病的诊断价值。

回顾性分析新疆维吾尔自治区儿童医院2015年3月至2017年12月经手术或经内镜逆行性胰胆管造影术活检证实的恶性低位胆道梗阻患者30例的临床资料。总结术前多层螺旋CT诊断的胆管癌、胰头癌和壶腹癌的影像学表现，并与病理活检结果进行对照，采用Kappa检验判断术前诊断与术后病理诊断的一致性。

30例患者多层螺旋CT均可清晰显示胆道系统扩张及远端梗阻部位胆管壁增厚、管腔狭窄。胆管癌表现为肝内胆管中、重度扩张，远端胆管呈"截断征"，梗阻部位可见软组织密度肿块沿胆管侧壁向管腔内生长；壶腹癌患者胆总管、胰管均扩张，呈典型"双管征"；胰头癌患者肿块密度不均，边界不清，强化不明显，呈相对低密度，胰体尾部常萎缩。多层螺旋CT诊断胆管癌准确性、敏感度、特异度分别为88.9%、88.9%、83.3%；诊断胰头癌准确性、敏感度、特异度分别为75.0%、85.7%、91.3%；诊断壶腹癌准确性、敏感度、特异度分别为75.0%、60.0%、96.0%。多层螺旋CT诊断与病理检查诊断结果经Kappa一致性检验分析，κ=0.70，P<0.01。

多层螺旋CT对于引起恶性梗阻性黄疸的壶腹区肿瘤术前诊断与病理诊断有较好一致性，能清晰显示胆道梗阻部位、程度、肿块以及与周围血管的关系，可作为临床诊断的常规影像学手段。

To investigate the value of multi-slice spiral CT imaging in the differential diagnosis of malignant low level biliary obstructive diseases of different tissue origins.

A retrospective analysis was performed of clinical data of 30 patients with malignant low level biliary obstruction confirmed by surgery or endoscopic retrograde cholangiopancreatography from March 2015 to December 2017 at Children's Hospital of Xinjiang Uygur Autonomous Region. The imaging findings of cholangiocarcinoma, pancreatic head cancer, and ampullary carcinoma diagnosed by multi-slice spiral CT were compared with pathological biopsy results, and the Kappa test was used to judge the consistency of preoperative diagnosis and postoperative pathology.

Multi-slice spiral CT in 30 patients can clearly show the dilatation of the biliary system, thickening of the bile duct wall, and stenosis of the distal obstruction. Cholangiocarcinoma was characterized by moderate-to-severe dilatation of the intrahepatic bile duct, the distal bile duct had a ″cut-off sign″, and the soft tissue density of the obstructed area can grow along the side wall of the bile duct. The common bile duct and pancreatic duct of ampulla cancer patients were expanded, showing a typical "double tube sign". In patients with pancreatic head cancer, the density of tumor was uneven, the boundary was unclear, the enhancement was not obvious, the density was relatively low, and the tail of the pancreas often shrank. Compared with the results of surgery and pathological diagnosis, the accuracy, sensitivity, and specificity of MSCT for diagnosing cholangiocarcinoma, pancreatic head cancer, and ampullary carcinoma were 88.9%, 88.9%, and 83.3%, 75.0%, 85.7%, and 91.3%, and 75.0%, 60.0%, and 96.0%, respectively. MSCT diagnosis and pathological examination had a good consistency (κ=0.70, P<0.01).

MSCT has a great consistency with pathology in preoperative diagnosis of ampullary tumors, and it can be used as a conventional radiographic means for diagnosis of ampullary tumors. CT imaging can clearly display tumor location, size, and the relationship with the surrounding tissue structure.