^99m Tc放射性核素肾静态扫描在发热性尿路感染急性期预测膀胱输尿管反流的效能评价

Efficacy of acute ^99m Tc-dimercaptosuccinic acid scan in predicting vesicoureteral reflux among young children with febrile urinary tract infection

目的 评价^99m Tc放射性核素肾静态扫描（DMSA）在婴幼儿发热性尿路感染急性期预测膀胱输尿管反流（VUR）的作用,探讨DMSA和排泄性膀胱尿路造影（MCU）在发热性尿路感染中应用的优先次序.方法 回顾性分析总结2000年1月到2009年12月间因发热性尿路感染就诊的年龄≤2岁婴幼儿的医疗记录和影像学资料.入组患儿均在就诊后1周内接受DMSA肾扫描、在感染控制后1周内行MCU检查.根据MCU检查结果分为无反流组、低级别VUR组和高级别VUR组.结果 共有370例患儿（男233例,女137例）纳入本研究,其中263例（71.1%）DMSA结果提示异常;126例经MCU证实患VUR（34.1%）,其中高级别VUB（Ⅲ～Ⅴ级）为103例（占到所有VUR的81.7%）.高级别VUR组DMSA结果异常率明显高于无反流组和低级别VUR组,其差异有统计学意义（P〈0.01）.DMSA检出高级别VUR（经MCU确诊）的敏感性为99.0%,阴性预测值为99.1%,阴性似然比（LR-）为0.03.结论 高级别VUR是婴幼儿发生肾损害的一个重要危险因素,DMSA检查为阴性的尿路感染患儿中高级别VUR的可能性较小.在婴幼儿发热性尿路感染急性期,DMSA在检出肾损害的同时对高级别VUR也有较好的预测能力,其应用次序可考虑优先于MCU.

Objective To evaluate the efficacy of ^（99m）Tc-dimercaptosuccinic acid （DMSA） scanning in predicting vesicoureteral reflux （VUR） among young children with febrile urinary tract infection （UTI） and to investigate the priority in applying either micturating eystourethrngraphy （MCU） or DMSA. Methods The medical records of children （age≤2 years）, presenting with febrile UTI between January 2000 and December 2009, were retrospectively reviewed. All cases underwent DMSA renal scan within 1 week after diagnosis and MCU within 1 week after infection. According to the results of MCU, children were divided into groups of non-VUR, low-grade and high-grade VUR. Results A total of 370 children （233 boys, 137 girls） were included, of whom 263 （71.1%） had abnormal DMSA results and 126 （34.1%） were identified as VUR on MCU. Among children with VUR, the number of high-grade was 103 （81.7%）. The rate of abnormal results on DMSA of high-grade VUR group was significantly higher than the rates of the other two groups （P 〈 0.01）. The sensitivity of DMSA for detecting high grade VUR was 99.0%. The negative predictive value was 99.1% and negative likelihood ratio was 0.03, respoctively. Conclusion High-grade VUR remains an important risk factor of renal damage for young children with febrile UTI. The possibility to detect high-grade VUR on MCU is rather low when the result of DMSA is negative. It is recommended that DMSA be used before MCU to investigate the febrile UTI children at acute phase, because it would predict the majority of children with high-grade VUR while detecting renal lesions.