Chavhan Govind, Daneman Alan, Moineddin Rahim, Lim Ruth, Langlois Valerie, Traubici Jeffrey
Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, 555 University Ave., Toronto, Canada, M5G 1X8.
Pediatr Radiol. 2008 Oct;38(10):1068-73. doi: 10.1007/s00247-008-0943-5. Epub 2008 Jul 17.
Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis.
To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine ((99m)Tc-MAG3) scan.
Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by (99m)Tc-MAG3 scan, of the obstructed kidney of > or =45% was considered normal and of < or =44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher's exact test was performed for assessing the association between DRF and altered echogenicity of the pyramids.
In group 1, which consisted of 13 patients with normal pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal pyramids and DRF (P=0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the pyramids with preserved CMD (group 2) compared to normal pyramid echogenicity (group 1) was 1.56 (95% CI 1.088-2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal pyramid echogenicity (group 1) was 5.571 (95% CI 1.530-20.294).
We observed that in obstructed kidneys the echogenicity of the pyramids may be abnormal. Increased echogenicity of the pyramids correlated weakly with abnormal DRF and does not necessarily indicate poor renal function. However, loss of CMD strongly correlated with poor renal function.
超声分辨率的提高以及高频换能器的应用，使得能够观察到以前未报道过的梗阻性肾盂积水患儿髓质锥体回声的变化。
确定输尿管肾盂连接部（UPJ）梗阻时肾锥体回声和形态的这些未报道的变化是否与通过锝-99m巯基乙酰三甘氨酸（（99m）Tc-MAG3）扫描测定的患肾的分肾功能（DRF）相关。
回顾性分析60例UPJ梗阻患儿的肾脏超声图像。根据锥体回声将患儿分为三组：（1）锥体回声正常；（2）锥体回声增强且皮质髓质分界（CMD）保持；（3）CMD消失。根据一项将组织学变化与DRF相关联的已发表研究，通过（99m）Tc-MAG3扫描测定，患肾的DRF≥45%被认为正常，＜或=44%被认为异常。采用Fisher精确检验评估DRF与锥体回声改变之间的关联。
第1组由13例超声显示锥体正常的患者组成，其中11例DRF正常，2例异常。第2组由33例锥体回声增强且CMD保留的患者组成，其中15例DRF正常，18例异常。第3组由14例CMD完全消失的患者组成，其中2例DRF正常，12例异常。锥体异常与DRF之间存在强相关性（P=0.0009）。与锥体回声正常（第1组）相比，锥体回声增强且CMD保留（第2组）的患肾DRF异常的风险比（RR）为1.56（95%CI 1.088-2.236）。与锥体回声正常（第1组）相比，CMD消失（第3组）的患肾DRF异常的RR为5.571（95%CI 1.530-2).294）。
我们观察到在梗阻性肾脏中锥体回声可能异常。锥体回声增强与DRF异常的相关性较弱，不一定表明肾功能差。然而，CMD消失与肾功能差密切相关。
