胎儿肺隔离症的MRI诊断

摘要

目的：探讨 MRI对胎儿肺隔离症的诊断价值。方法：回顾性分析8例经产后病理证实的胎儿肺隔离症病例的影像学表现，产前超声初步诊断为肺隔离症和／或先天性囊性腺瘤畸形，再行胎儿胸部 MRI 检查。MRI 检查时孕妇年龄22～36岁，孕龄20～35周。胎儿 MRI检查序列包括TSE T1 WI、HASTE T2 WI和抑脂Tirm T2 WI，行矢状面、冠状面和横轴面扫描。结果：8例胎儿肺隔离症中7例为产后手术病理证实，1例为引产后尸检证实。其中病灶位于左侧7例，右侧1例。8例肺隔离症中叶内型7例，均位于下叶基底段，大小为2．6 cm×3．1 cm～4．2 cm×4．7 cm，其中1例合并先天性肺囊腺瘤样畸形；叶外型1例。叶内型肺隔离症MRI表现为一侧肺下叶T2 WI团块状高信号影，边界较清晰，信号高于邻近正常肺组织；7例均可见体循环异常分支供血，供血血管均发自主动脉，T2 WI 呈线条状低信号。其中合并肺囊腺瘤样畸形1例，表现为左下肺团块状高信号周围可见密集的高信号小囊泡状影，并可见一T2 WI 低信号血管影与主动脉相连。叶外型1例，隔离肺组织表现为位于左肾与膈之间的囊状 T2 WI 高信号，T2 WI 低信号血管影与腹主动脉相连。结论：MRI可直接显示胎儿隔离肺的位置和形态，并确定其供血血管，对于胎儿肺隔离症的诊断具有较高价值，可作为产前胎儿超声检查的重要补充。%Objective:To explore the diagnostic value of MRI in fetal bronchopulmonary sequestration (BPS ). Methods:There were 8 cases of BPS proven by postnatal pathological results.All the cases were suspected with BPS and/or congenital cystic adenomatoid malformation (CCAM)by antenatal ultrasound.These pregnant women,being 22 to 36 years old,were in their 20~35 gestational weeks and underwent MRI scan after antenatal ultrasound.MR sequences included HASTE T2 WI,fat suppression Tirm T2 WI and TSE T1 WI.Axial,coronal and sagittal scanning was performed.Results:In all cases,7 cases were proven by surgical pathology and one case was diagnosed by autopsy.The locations of BPS were left lower lobe (6 cases),right lower lobe (1 case)and left adrenal region (1 case).CCAM was diagnosed in 1 case.T2-weigh-ted images revealed a hyperintense homogeneous lesion occupying the lower hemithorax and supplied with arterial systemic blood originating from the aorta in all cases of intralobar BPS.The feeding artery showed hypointensity on T2 WI.T2-weigh-ted images showed a unilateral multilocular cystic lesion involving the left lower lobe adjacent to BPS in the case of CCAM with BPS.And the hyperintense feeding artery was also shown.T2-weighted images revealed a hyperintense homogeneous cystic lesion in left adrenal region and a feeding artery originating from the abdominal aorta.Conclusion:MRI directly shows the location,distribution and morphology of bronchopulmonary sequestration in the fetus,and can find the feeding arteries. It can help make diagnosis for bronchopulmonary sequestration.MRI should be an important methed as supplement to ante-natal ultrasound.