胎儿CCAM的MRI表现及变化特点

Characteristics of MR imaging manifestations and changes in fetus with congenital cystic adenomatoid malformation

目的:探讨胎儿先天性肺囊腺瘤样畸形(CCAM)的MRI表现及变化特点。方法:回顾性分析75例经产后CT及手术病理证实为CCAM的患者产前MRI资料,其中有4例在产前行两次MRI检查。由两名高年资胎儿影像诊断医师阅片,分析不同分型CCAM产前主要影像表现,并与产后CT对比。结果:75例CCAM患者中,17例为Ⅰ型CCAM,19例为Ⅱ型CCAM,39例为Ⅲ型CCAM。Ⅰ型和Ⅱ型CCAM在产前SSFSE序列图像主要表现为单或多发大小不等囊性或囊实性高信号影,产前囊肿大小与产后CT气囊大小可不一致。Ⅲ型CCAM产前主要表现为均匀实性高信号影,所有病灶均未见体循环动脉分支供血。4例前后两次MRI检查患者均为Ⅲ型CCAM,其中2例病灶体积及信号均减小,2例病灶完全消失。结论:CCAM的产前MRI具有较特征性表现。随着胎龄增长,病灶大小及信号可呈动态变化过程,部分甚至会消失,但仍建议产后CT检查。

Objective：To investigate the characteristics of MR imaging manifestations and changes in fetus with congenital cystic adenomatoid malformation（CCAM）.Methods：75 children with CCAM proved by CT and pathology were retrospectively analyzed and compered with prenatal MRI.Of the 75 cases,four underwent two MRI examinations.The fetal MRI images were analyzed and diagnosed by two experienced senior radiologists.Different types of CCAM were summarized.The changes of the volume and signal of lesions in 4 cases were calculated with their two MRI examinations.Results：Of the 75 cases diagnosed as CCAM,17 were confirmed as type Ⅰ,19 type Ⅱ and 39 type Ⅲ.TypeⅠ and Ⅱ were characterized by one or multiple cysts/mixed high signal on SSFSE.The size of prenatal cyst may or may not be different from that of postnatal CT balloon.TypeⅢ was characterized by homogeneous solid high signal lesions.There was no evidence of systemic arterial blood supply in all lesions.Four cases with two MRI examinations were confirmed as type Ⅲ;2 of them showed decrease in volume and signal,and the other 2 lesions disappeared completely.Conclusion：CCAM has a relatively specific imaging finding on prenatal MRI,With the increase of gestational,The size of the lesions may change dynamically.Some lesions appear to regress or disappear completely,but postnatal CT examination is still recommended.