Gd-EOB-DTPA增强MRI对无周围胆管扩张的肿块型肝内胆管癌中的诊断价值

Diagnostic Value of Gd-EOB-DTPA-Enhanced MRI in Intrahepatic Mass-Forming Cholangiocarcinoma Without Peripheral Bile Duct Dilatation

目的 探讨Gd-EOB-DTPA增强MRI对不伴有周围胆管扩张的肿块型肝内胆管癌(IMCC)中的诊断价值。方法 回顾性分析本院术前行Gd-EOB-DTPA检查术后经病理证实的33例孤立性无周围胆管扩张的IMCC患者的基本MRI征象、动态多期增强强化特征以及肝胆期(HBP)表现。根据肿瘤动脉期强化特点分为经典型和富血供型,测量并计算HBP病灶及周围肝实质的信号强度(SI)比,对比两型间的差异。结果 33例无周围胆管扩张的IMCC,T2WI以混杂稍高信号为主(26/33,78.8%),伴中央高信号(13/26,50.0%)或低信号区(7/26,26.9%),66.7%(22/33)DWI上呈“靶征”,75.8%(25/33)HBP呈“EOB云”。其中,经典型(n=27)IMCC表现为周边环状强化伴中心渐进性延迟强化;富血供型IMCC(n=6)表现为全瘤(n=2)或近乎全瘤(n=4)强化伴持续性强化(n=5)或廓清(n=1)表现。两型IMCC在慢性乙肝、肝硬化感染率(11.1%vs 66.7%,P=0.011)及肿瘤大小(3.9 cm vs 2.8 cm,P=0.019)具有统计学差异,在伴随征象(肝包膜回缩、DWI靶征、“EOB云”征)、周边廓清及HBP病灶/肝脏SI比(0.67 vs 0.58)无统计学差异(P均>0.05)。结论 无周围胆管扩张的IMCC根据动脉期强化特点分经典型和富血供型,DWI“靶征”及“EOB云”征有助于IMCC的诊断。较经典型IMCC,富血供型IMCC常发生于慢性乙肝、肝硬化背景下,瘤体相对偏小。

Objective To evaluate the value of Gd-EOB-DTPA-enhanced MRI in mass-forming intrahepatic cholangiocarcinoma(IMCC) without peripheral bile duct dilatation. Methods 33 pathologically confirmed solitary IMCCs without peripheral bile duct dilatation were retrospectively analyzed for basic MRI signs, Gd-EOB-DTPA-enhanced images and hepatobiliary phase sign. Each IMCC was categorized into either the classic IMCC group or hypervascular IMCC group according to the enhancement patterns in the arterial phase, and the MRI features and HBP signal intensity(SI) ratio of both IMCC groups were compared. Results On the T2WI, IMCC mainly showed high mixed signal(26/33, 78.8%), with 50.0%(13/26) hyperintensity areas or 26.9%(7/26) hypointense areas. 66.7%(22/33) showed target-sign on DWI and 75.8%(25/33) showed "EOB cloud’’ on HBP. Classic IMCCs(n=27) showed peripheral rim enhancement at arterial phase with centripetal enhance in the delayed phases, Hypervascular IMCCs(n=6) showed complete(n=2) or nearcomplete(n=4) arterial enhancement and persistent enhancement(n=5) or washout(n=1) on delayed phases. Both IMCC groups have statistical differences in chronic hepatitis B infection rate(11.1% vs 66.7%, P=0.011) and tumor size(3.9 cm vs 2.8 cm, p=0.019), and no statistical differences in ancillary imaging features(tumor capsule retraction, target-sign on DWI and "EOB cloud"), peripheral washout and HBP mean SI ratio(0.67 vs 0.58)(each P>0.05). Conclusion IMCCs without peripheral bile duct dilatation were categorized into either the classic IMCC group or hypervascular IMCC group according to the enhancement patterns in the arterial phase, target sign on DWI and “EOB cloud” on HBP are helpful for IMCC diagnosis. Compared with classic IMCCs, hypervascular IMCCs were often occured with hepatitis B cirrhosis and the median size of tumors was relatively smaller.