腔静脉后输尿管是一种少见的先天异常。以往该病的影像诊断主要靠X线静脉尿路造影，但诊断比较困难，术前确诊率低。我们于1988～1991年间共发现3例，均经临床、手术证实，现报道如下。临床资料例1，男，37岁。3年前体检时B超发现右肾盂积水，当时无明显症状，近一周感右腰部胀 Vena cava behind the ureter is a rare congenital anomaly. In the past the imaging diagnosis of the disease mainly rely on X-ray venography, but the diagnosis is more difficult, low preoperative diagnosis. We found a total of 3 cases between 1988 to 1991, both clinically and surgically confirmed, are reported below. Clinical data example 1, male, 37 years old. B-3 years ago when the physical examination found that the right hydronephrosis, no obvious symptoms, nearly a week feel the right lower back swollen