Lautin E M, Haramati N, Frager D, Friedman A C, Gold K, Kurtz A, Self J
Department of Radiology, Montefiore Medical Center, Bronx, NY 10467.
AJR Am J Roentgenol. 1988 Mar;150(3):591-4. doi: 10.2214/ajr.150.3.591.
Variability in the normal course of the ureter makes it difficult to differentiate a normal variant from a congenital anomaly or deviation caused by a mass. CT can be useful in making this distinction. We present five cases of circumcaval ureter in which contrast-enhanced CT, by showing the ureter passing posterior and medial to the inferior vena cava (IVC), provided the definitive diagnosis. In addition, we studied the position of the inferior vena cava in the midlumbar region in 100 consecutive contrast-enhanced CT scans and compared the results with the position of the IVC in our five cases of circumcaval ureter plus one case of circumcaval ureter taken from the literature. Whereas only 6% of the normal patients had an IVC lateral to the right pedicle of the third lumbar vertebra, all of the patients with a circumcaval ureter and the one case in the literature had the IVC lateral to the pedicle. Therefore, the finding of a laterally placed IVC on CT is suggestive but not pathognomonic of circumcaval ureter. Contrast-enhanced CT can be used to prove the diagnosis of circumcaval ureter, and lateral placement of the IVC on non-contrast-enhanced CT suggests the diagnosis.
输尿管正常走行的变异使得区分正常变异与先天性异常或由肿块引起的偏差变得困难。CT有助于做出这种区分。我们报告了5例腔静脉后输尿管病例，其中增强CT显示输尿管从下腔静脉（IVC）后方和内侧通过，从而做出了明确诊断。此外，我们在100例连续的增强CT扫描中研究了中腰部区域下腔静脉的位置，并将结果与我们的5例腔静脉后输尿管病例以及文献中的1例腔静脉后输尿管病例的下腔静脉位置进行了比较。正常患者中只有6%的下腔静脉位于第三腰椎右椎弓根外侧，而所有腔静脉后输尿管患者及文献中的1例病例的下腔静脉均位于椎弓根外侧。因此，CT上发现下腔静脉位置偏外侧提示腔静脉后输尿管，但并非确诊依据。增强CT可用于确诊腔静脉后输尿管，非增强CT上IVC位置偏外侧提示该诊断。
