肝外胆管癌的MSCT诊断

目的探讨肝外胆管癌的MSCT表现及其诊断价值。方法收集我院2008年-2011年经手术或穿刺病理证实肝外胆管癌23例，所有患者行16层螺旋CT平扫、动脉期、静脉期、延迟期扫描，并经MPR、CPR处理，回顾分析胆管癌各期CT表现及胆管癌显示率。结果肝外胆管癌上段9例，中段8例，下段6例；动脉期16例轻度强化，4例中度强化；静脉期3例轻度强化，13例中度以上强化，4例明显强化；2例动脉期、静脉期均呈明显强化；22例延迟期中度以上强化，1例各期无明显强化：CT直接征象为胆管不规则局限性增厚、环状不均匀增厚或表现为结节、肿块状，间接征象为肝内外胆管扩张：MPR、CPR能直接显示病变范围、狭窄程度及周围浸润情况。结论合理运用MPR、CPR技术，能准确显示肝外胆管癌直接征象、位置及浸润范围，结合各期CT表现，对确立诊断及指导临床治疗具有重要价值。

CT diagnosis of extrahepatic cholangiocarcinoma

Objective To explore the features and diagnostic value of MSCT of extrahepatic cholangiocarcinoma. Methods From 2008 through 2011, 23 patients with pathologically-proven extrahepatic cholangiocarcinomas underwent 16-slice spiral CT without and with contrast enhancement in the arterial, venous and delayed phases. CT images of all patients were retrospectively analyzed. Results The tumors involved the upper（9）, middle（8）, and lower （6） segments of the extrahepatic bile ducts. CT showed slight contrast enhancement of the tumors in the arterial phase （16）, slight （3） and moderate （13） contrast enhancement in the venous phase. The tumors in 4 patients enhanced moderately in the arterial phase and markedly in the venous phases. CT showed marked tumor contrast enhancement in both the arterial and venous phases in two patients. Moderate tumor contrast enhancement in the delayed phase was noted in 22 patients and no contrast enhancement was seen in any of the phases in 1 patient. The direct signs of extrahepatic cholangiocarcinoma on CT were focal irregularity, circumferential or asymmetric thickening, and nodularity of the extrahepatic bile ducts. The indirect sign was intra-or extrahepatic bile duct dilatation. The multiplanar reconstructed （MPR） and CPR images displayed the bile duct tumor and severity of ductal obstruction as well as tumor infiltration of surrounding structures. Conclusion MPR and CPR techniques can clearly display the location and extent of tumor. Rational use of the reconstruction methods together with the contrast enhancement pattern in different phases can aid the diagnosis and management of extrahepatic cholangiocarcinoma.