Zerin J M, Hernandez R J, Sedman A B, Kelsch R C
University of Michigan Hospitals, Ann Arbor.
Pediatr Radiol. 1991;21(4):267-9. doi: 10.1007/BF02018620.
Compression of the left renal vein (LRV) between the superior mesenteric artery and the aorta is thought to be a cause of hematuria, periureteral and gonadal varices, and varicocele ("Nutcracker phenomenon"). Previous investigators have suggested that this diagnosis can be made on computed tomography when the LRV ratio greater than or equal to 1.5 (the diameter of the LRV proximal to the aorto-mesenteric angle divided by the diameter of the LRV distal to the aorto-mesenteric angle). This study was designed to establish the normal range for the LRV ratio on CT in children. The LRV ratio was measured in thirty-nine consecutive children undergoing intravenously enhanced CT of the abdomen. None of the children had hematuria on urinalysis immediately before or after the CT. Children with any known abnormality involving the kidneys, adrenal glands, IVC, or renal or gonadal veins were excluded. The patients ranged in age from 3.4 to 18.5 years (mean = 10.6 years). LRV ratio ranged from 0.78 to 2.00 (mean = 1.46; S.D. = 0.312). Twenty of the 39 children (51.3%) had a LRV ratio greater than or equal to 1.50. The conclusion is that the normal range for the LRV ration is too wide for it to be useful in diagnosing LRV entrapment and that a LRV ratio greater than or equal to 1.5 on CT is normal in children.
肠系膜上动脉与腹主动脉之间的左肾静脉（LRV）受压被认为是血尿、输尿管周围和性腺静脉曲张以及精索静脉曲张（“胡桃夹现象”）的一个病因。先前的研究者提出，当LRV比率大于或等于1.5（腹主动脉-肠系膜夹角近端的LRV直径除以腹主动脉-肠系膜夹角远端的LRV直径）时，可通过计算机断层扫描做出这一诊断。本研究旨在确定儿童CT上LRV比率的正常范围。对39例连续接受腹部静脉增强CT检查的儿童测量LRV比率。这些儿童在CT检查前后的尿液分析中均无血尿。排除任何已知的涉及肾脏、肾上腺、下腔静脉或肾静脉或性腺静脉异常的儿童。患者年龄范围为3.4至18.5岁（平均=10.6岁）。LRV比率范围为0.78至2.00（平均=1.46；标准差=0.312）。39例儿童中有20例（51.3%）的LRV比率大于或等于1.50。结论是，LRV比率的正常范围过宽，无法用于诊断LRV受压，且儿童CT上LRV比率大于或等于1.5是正常的。
