MRI在胆管内乳头状黏液性肿瘤诊断及鉴别诊断中的价值

Value of MRI in Diagnosisd and Different Diagnosis of Intraductal Papillary Mucinoous Neoplasm of the Bile Tract

目的 探讨MRI在胆管内乳头状黏液性肿瘤(IPMN-B)诊断中的价值。方法 回顾性分析经手术或穿刺活检病理证实的16例IPMN-B的MRI特征,重点分析钆塞酸二钠(Gd-EOB-DTPA)增强MRI特征。结果 16例中,典型IPMN-B 8例,囊性IPMN-B 3例,无肿块型IPMN-B 5例。8例典型IPMN-B扩张胆管内见单发或多发肿瘤,呈乳头状或息肉状,T_(1)WI呈稍低信号,T_(2)WI呈稍高信号,扩散加权成像(DWI)呈高信号,钆喷酸葡胺(Gd-DTPA)增强后动脉期轻度强化,门静脉期、延迟期渐进性轻中度强化,肿瘤上下游胆管均明显广泛扩张。3例囊性IPMN-B呈动脉瘤样明显扩张,其中2例囊性IPMN-B见附壁结节,1例囊性IPMN-B囊内仅见多发分隔,病变与胆管系统相通。5例无肿块型IPMN-B未见明显肿瘤,仅表现为病变区胆管壁增厚,病变区胆管呈广泛明显扩张。Gd-EOB-DTPA增强MRI胆管期,正常胆管表现为高信号充盈,黏液分布区扩张胆管表现为充盈缺损。结论 MRI、磁共振胰胆管造影(MRCP)可有效评价常见类型的IPMN-B。Gd-EOB-DTPA增强MRI有助于IPMN-B黏液成分与其他胆管囊性病变及梗阻性胆管扩张的鉴别,对无肿块型及囊性IPMN-B诊断及鉴别诊断具有较高价值。

Objective To investigate the value of MRI in diagnosis of intraductal papillary mucinous neoplasm of the bile tract(IPMN-B).Methods The MRI features of 16 cases with IPMN-B proved by pathology were retrospectively analyzed,focusing on the analysis of Gd-EOB-DTPA-enhanced MRI.Results Of the 16 cases,7 were typical IPMN-B,3 were cystic-forming IPMN-B,and 5 were non-tumor IPMN-B.Solitary and multiple tumors were found in 8 typical IPMN-Bs.The papillary or polypoid tumors showed low-signal on T_(1)WI,high-signal on T_(2)WI and DWI.On the dynamic contrast-enhanced Gd-DTPA MRI,the tumors showed mild enhancement in arterial phase,and gradually mild to moderate enhancement in portal vein phase and delayed phase.Both upstream and downstream bile ducts were dilated in typical IPMN-Bs.Aneurismal dilatation of bile ducts were found in cystic-forming IPMN-Bs,mural nodules were found in 2 cystic-forming IPMN-Bs,Multiple septums were found in 1 cystic-forming IPMN-B.Wall thickening of the bile duct were found 5 non-tumor IPMN-B cases,without tumors,the bile ducts were widely dilated.Gd-EOB-DTPA-enhanced MRI revealed low signal intensity filling defect of mucin in the dilated bile ducts in hepatobiliary or bile duct phase,while the normal bile duct showed high-signal.Conclusion The common IPMN-B can be effectively evaluated by MRI and MRCP.Gd-EOB-DTPA-enhanced MRI is helpful to confirm the mucus components in IPMN-B and differentiated it from other cystic or obstructive diseases of the bile duct,especially the cystic-forming and non-tumor IPMN-Bs.