探讨胎儿后尿道瓣膜的超声图像特征，总结鉴别诊断要点。

对2014年12月至2016年12月在中国医科大学附属盛京医院产前超声检查疑诊下尿道梗阻的14例男性胎儿的声像图表现及产后随访结果进行分析，总结后尿道瓣膜超声图像特点及鉴别诊断要点。

14例下尿道梗阻男性胎儿中产前超声诊断后尿道瓣膜11例，超声均表现为膀胱增大，膀胱壁增厚，其中7例伴"钥匙孔"征；其余3例中1例诊断尿道闭锁，2例超声提示膀胱增大、下尿道梗阻可能性大。经产后超声随访、膀胱镜检查及手术检查证实，11例为后尿道瓣膜，1例尿道闭锁，2例膀胱输尿管反流。其中1例产前诊断后尿道瓣膜，产后证实为膀胱输尿管反流；2例产前超声提示膀胱增大，产后证实1例为后尿道瓣膜，1例为膀胱输尿管反流。

产前超声可通过观察膀胱解剖形态及伴发畸形诊断胎儿后尿道瓣膜，为临床提供有价值的诊断信息。

To investigate the value of prenatal ultrasound in diagnosis of fetal posterior urethral valve (PUV) and the differential diagnosis of related diseases.

The antenatal ultrasonographic manifestations and the outcomes of 14 cases with congenital lower urinary tract obstruction (LUTO) in Shengjing Hospital of China Medical University from December 2014 to December 2016 were analyzed. The ultrasound features and differential diagnosis of fetal posterior urethral valve were summarized and analyzed.

Fourteen male fetuses with LUTO were prenatally diagnosed. Eleven fetuses were diagnosed as PUV, 1 as urethral atresia, 2 as megacystis and LUTO. Among the fourteen fetuses, 11 were confirmed as PUV after delivery, 1 as urethral atresia, 2 as vesicoureteral reflux (VUR). One case among them was diagnosed as PUV, and latter proved to be VUR. In 2 cases among them, prenatal ultrasound indicated megacystis, but 1 case was proved to be PUV, and 1 case was VUR. The prenatal ultrasound of the PUV fetuses showed enlarged bladder and thickened bladder wall. Most of them were accompanied by the keyhole sign.

Prenatal ultrasound can assist in the diagnosis of PUV by analyzing the anatomy of the bladder and accompanying malformations, which provides valuable diagnostic information for the clinical practice.