Ⅰ型先天性胆总管囊肿胎儿期MRI表现

Prenatal MRI findings of typeⅠcongenital choledochal cyst

目的观察Ⅰ型先天性胆总管囊肿(CCC)胎儿MRI表现。方法以18名健康儿童为对照(对照组),分析21例出生后证实的Ⅰ型CCC患儿(CCC组)的基本资料及其胎儿期MRI,测量CCC病灶体积、观察其形态、走行方向、是否与肝内胆管相通及末端胆管是否显示等,比较组间胎儿胆囊、肝脏、脾脏最大截面面积及门静脉直径差异,分析CCC病灶体积与MRI测量指标的相关性。结果21例CCC,男4例、女17例,MR检查时平均胎龄(26.9±4.6)周;18胎CCC病灶为纺锤形,3胎为类圆形;轴位、冠位及矢状位MRI中,病灶长轴方向均为左上-右下方向(斜纺锤征)。单次激发快速自旋回波序列MRI见21胎病灶上端均呈尖角征,17胎下端见尖角征,且明确显示纤细纡曲末端胆管。胎儿期CCC组胆囊最大截面面积小于对照组(P<0.05),而门静脉直径大于对照组(P<0.05);CCC病灶体积与门静脉直径呈正相关(r=0.710,P<0.05)。结论CCC胎儿期MRI表现为胆囊缩小、门静脉增宽,病灶多呈纺锤形;轴位、冠位及矢状位MRI均见斜纺锤征及上下端尖角征有助于诊断CCC。

Objective To observe prenatal MRI findings of typeⅠcongenital choledochal cyst(CCC).Methods Taken 18 healthy children as controls(control group),the basic data and fetal MRI of 21 children with confirmed typeⅠCCC after birth(CCC group)were retrospectively analyzed.The volume of CCC lesion on fetal MRI was measured,the morphology and direction of the lesion were observed,and whether the lesion communicated with intrahepatic bile duct and the display of terminal bile duct or not were evaluated.The maximal cross-sectional area and portal vein diameter of fetal gallbladder,liver and spleen on fetal MRI were compared between groups.The correlation between CCC lesion volume and MRI measurement indices were analyzed.Results Among 21 children with CCC,4 were males and 17 were females,and the mean gestational age at the time of MR examination was(26.9±4.6)weeks,while the foci of CCC were fusiform in 18 fetuses and circular in 3 fetuses.On axial,coronal and sagittal fetal MRI,the long axis directions of 21 fetal lesions were all in the upper left-lower right direction(oblique spindle sign).On single shot fast spin echo sequence MRI,sharp angle sign was found at the upper end of the lesions in 21 fetuses and at the lower end in 17 fetuses,and slender tortuosity terminal bile ducts could be clearly demonstrated.The maximum cross-section area of the gallbladder in CCC group was smaller than that in control group(P<0.05),but the diameter of portal vein was larger than that in control group(P<0.05).The lesion volume of CCC was positively correlated with portal vein diameter on fetal MRI(r=0.710,P<0.05).Conclusion Fetal MRI findings of CCC included reduced gallbladder volume and widened portal vein.Most of CCC lesions were fusiform,the oblique spindle sign and the sharp angle sign at the upper and lower end found on all axial,coronal and sagittal fetal MRI contributed to diagnosing CCC.