肝外胆管梗阻病变CT诊断的评价

Evaluation of CT in the differential diagnosis of extrahepatic biliary obstructive diseases

目的：通过分析良恶性肝外胆管梗阻病变的ＣＴ表现，总结出有鉴别诊断意义的征象。材料与方法：复查分析经手术和病理证实、术前均做了ＣＴ检查的肝外胆管梗阻病变１１７例，良性３８例，恶性７９例。结果：肝外胆管远段梗阻，梗阻部胆管呈漏斗样改变，肝外胆管壁呈环形弥漫型增厚，肝内胆管呈竹节状或小囊状轻、中度扩张，梗阻部肿块内钙化，边界清楚对良性病变诊断有重要意义；肝外胆管中、近段梗阻或肝外胆管未显影者，梗阻部胆管呈截断型或突然狭窄型并伴肿块，肝外胆管壁呈环形局限型增厚，肝内胆管呈藤状或蟹足状中度或重度扩张，梗阻部肿块边界不清，其内可见坏死等征象，高度提示恶性病变。结论：良恶性肝外胆管梗阻病变均有其特征性的ＣＴ征象，注意观察胆管的形态改变，以及与周围组织结构关系，并紧密结合临床综合分析，有助于提高诊断准确性。

Purpose: To evaluate some specific CT findings used to differentiate the nature of bi liary obstructive diseases. Materials and methods: Preoperative CT images of 117 consecutive cases of proved extrahepatic biliary obstructive diseases (79 malignant and 38 benign) were analyzed. Results: Obstruction of the distal portion of extrahepatic biliary duct was often seen in benign cases, and malignant obstructions were mostly found at the proximal portion. Dilated extrahepatic bile duct ending abruptly or narrowing sharply with mass at the obstructed portion was typical of malignancy; whereas gradual tapering of common bile duct at the obstructed level usually indicated benign nature. Focal thickening of common bile duct wall was more often seen in malignant diseases, while diffuse thickening was more indicative of benign lesions because of inflammatory changes. Mild degree of dilated intrahepatic bile ducts was usually found in benign diseases, and marked degree of dilatation in malignant lesions. Viny dilatation of intrahepatic bile ducts was one of the characteristic signs of malignant lesions, while segmental dilatation was diagnostic in benign disease. Calcification and distinct margin of the mass at obstructed portion were usually seen in benign structures, while lower density (necrosis) with indistinct margin emerged often in the structure of malignant mass. Conclusion: Specific signs of CT images were found in either benign or malignant lesions. Careful scrutiny of the morphological changes of the bile duct, and its relationship with the surrounding tissue, in combination with the clinical analysis would help to increase the rate of accuracy of diagnosis.