周围型肝内胆管细胞癌的MRI诊断

MRI diagnosis of peripheral cholangiocarcinoma

目的 分析周围型肝内胆管细胞癌 (PCC)的MRI表现及其误漏诊原因。方法 收集 12例经手术、病理证实的PCC (其中术前MRI误漏诊 3例 ) ,常规行T1WI和 /或准T1WI、T2 WI和 /或脂肪抑制T2 WI;加行动态增强扫描 10例 ,磁共振胰胆管造影 (MRCP) 10例。常规行横断面扫描 ,辅以冠状及矢状面扫描。结合手术及病理所见分析MRI表现。结果 周围型肝内胆管细胞癌MRI主要表现为不规则浸润性占位 ,T1WI均呈混杂低信号 ,实质部分呈略低信号 ,坏死、囊变区呈低信号 ,间杂扩张的小胆管或黏液湖呈更低信号。T2 WI均呈混杂的高信号 ,实质部呈略高信号 ,坏死、囊变区及扩张小胆管与黏液湖呈明显高信号。多可见病灶内或周围扩张小胆管。动态增强扫描示动脉期病灶强化不明显或病灶边缘及部分实质轻度强化 ,门静脉期及延时扫描病灶呈进行性、向心性强化。MRCP可见病灶区胆管走向杂乱、僵直、各种形态截断狭窄及病灶周围小胆管扩张。MRI漏诊原因 :例 1为多次胆道结石术后残余结石并发PCC ,且部分PCC坏死囊变区感染形成肝脓肿。例 2为多次胆道结石术后再发肝内外胆管结石 ,并发肝硬化、PCC ,且PCC多发坏死囊变。例 3为肝内外胆管、胆囊多发结石并炎症 ,右肝明显萎缩并发PCC。结论 PCC的MRI表现具有一定的特点 ,诊断准确率较高 ,

Objective To analyse MRI findings of peripheral cholangiocarcinoma(PCC)and the causes of misdiagnosis and missed diagnosis.Methods Twelve cases of PCC confirmed surgically and pathologically were collected.Examination techniques T 1WI and(or)T 1 WI,T2 WI and(or)fat-suppressed T2WI were routinely performed.Dynamic enhancements were added in 10 cases and MRCP 10 cases.MRI findings along with operational and pathological findings were analysed.Results PCC were mainly shown as irregular infiltrative masses.On T 1WI the masses were all with mixed hypointensity,the solid parts of the masses were with slightly low signals,the necrotic and cystic parts were with low signals,the mixed and dilated smallbile ducts or mucous lakes were with even lower signals.On T 2WI all the masses were shown as mixed hyperintensity,the solid parts of which were with slightly high signals,the necrotic and cystic part,dilated small bile ducts and mucous lakes were all with higher signals.The dilated small bile ducts inside or around the lesions were frequently seen.Dynamic Enhancement:At aterial phase the lesions showed no obvious enhancement,or slight enhancements at the edge or solid parts of the lesions;at portal venous phase and delayed phase progressive and concentric enhancement were shown.With MRCP disoriented,rigid bile ducts were shown,and some bile ducts around the mass were truncated narrow with pre-stenotic dilatation.At pre-operational diagnosis lesions were missed in three cases,the cases were discussed.Conclusion PCC has certain characteristic manifestation on MRI.MRI diagnosis of the disease is quite accurate.But analysis should be based on the combination of MR plain scan,dynamic enhancement and MRCP,it stil needs to get rid of the interference of the images of biliary calculus along with hepatic abscess.In this way misdiagnosis and missed diagnosis could be diminished.