^99Tc^m-DMSA肾皮质显像预测急性肾盂肾炎患儿肾瘢痕危险性的价值

The valuation of ^99Tc^m-DMSA renal cortical scintigraphy for prediction of renal scarring in children with acute pyelonephritis

目的应用^99Tc^m-二巯基丁二酸（DMSA）肾皮质显像预测急性肾盂肾炎（APN）患儿肾瘢痕危险性及分析相关危险因素。方法研究对象为118例临床首次诊断为APN的患儿，男44例，女74例，年龄1个月至14岁。所有患儿急性期行^99Tc^m-DMSA肾皮质显像，根据肾受累范围将肾损害程度分为5级，0级为肾功能正常，肾损害自轻度到重度依次分为Ⅰ至Ⅳ级，治疗至少6个月再次显像判断是否形成肾瘢痕。72例患儿进行直接法核素膀胱显像（DRC）评价膀胱输尿管反流（VUR），反流程度分为轻、中、重度。应用SPSS 11．5软件，分别对相应数据进行Spearman等级相关分析。结果118例患儿以单肾为单位共236个肾，急性期（发病2周内）肾显像结果，正常肾组79个，Ⅰ级肾损害组64个，Ⅱ级肾损害组51个，Ⅲ级肾损害组19个，Ⅳ级肾损害组23个。6个月后再次显像显示肾功能正常组无一个肾形成肾瘢痕；肾损害形成肾瘢痕的发生率分别为Ⅰ级7．81％（5／64），Ⅱ级49．02％（25／51），Ⅲ级68．42％（13／19），Ⅳ级100．00％（23／23）。肾瘢痕发生率与首次肾显像肾损害程度呈明显正相关（r=0．877，P〈0．01）。另外，72例进行DRC患儿中，以单肾为单位共144个肾，VUR发生率54．17％（78／144），其中轻、中、重度反流。肾分别为4，43和31个。66个无VUR肾瘢痕发生率仅为4．55％（3／66），肾瘢痕发生率在轻度VUR为1／4，在中度VUR为46．51％（20／43），在重度VUR为87．10％（27／31）。VUR与肾瘢痕形成呈明显正相关（r=0．624，P〈0．01）。结论APN患儿急性期^99Tc^m-DMSA。肾皮质显像肾损害程度分级对预测肾瘢痕危险性有重要价值，肾损害程度越重，VUR程度越重，肾瘢痕形成危险性越大。对于急性期有肾损害，尤其是Ⅱ级以上肾损害、伴有输尿管反流的APN患儿应重视，积极治疗，以预防或减少永久性肾损害发生。

Objective Acute pyelonephritis （APN） is a common infectious disease in childhood. APN may resuh in irreversible renal scarring. ^99Tc^m-dimereaptsuecinie （DMSA） renal cortical scintigraphy was reported to be highly sensitive and specific for detection APN and renal scarfing. The aim of this study was to determine the incidence of renal scarring in a group of children with APN and to evaluate the relative factors at risk of scarring using ^99Tc^m-DMSA renal cortical scintigraphy. Methods One hundred and eighteen patients （44 males, 74 females, age range： 1 month to 14 years） with APN underwent DMSA renal cortical scan before treatment and six month after treatment to identify renal damage and renal scarring. The degree of renal damage was divided to grade I to IV. A directed radionuelide cystography （DRC） was performed in 72 cases to evaluate vesicoureteric reflux （VUR）. Statistical analysis between all those relative factors was performed using Spearman grading relational analysis. The software was SPSS 11.5. Results The follow-up renal cortical scan revealed that 79 normal kidneys on first scan remained normal ; of 64 kidneys with grade I damage, 7.81% （5/64） developed renal scar; of 51 kidneys with grade Ⅱ, 49.02% （25/51） developed renal scar; of 19 with grade m, 68.42% （13/19） developed renal scar; of 23 with grade Ⅳ, 100.00% （23/23） developed renal sear. There was a significant relationship between the incidence of renal scar on follow-up and the grade of renal damage on first scan （r = 0. 877, P 〈 0.01 ）. VUR was found in 54.17% （78/144） per renal unit. Only 4.55% （3/66） of those with non-refluxing ureters de- veloped renal scars on follow-up. One of four patients with mild-refluxing ureters developed renal scars. 46. 51% （20/43） of those with moderate-refluxing ureters developed renal scars. 87.10% （27/31 ） of those with severe-refluxing ureters developed renal scars. There was a significant relationship between the incidence of renal scarfing in follow-up and the grade of VUR （ r = 0. 624, P 〈 0. 01 ）. Conclusions There are important clinical progllostic values on the risk prediction of renal scarring by using DMSA renal cortical scan in children with APN. Higher grade of renal damage on first DMSA cortical scan and higher grade of VUR predicted greater chance of future development of renal scan＇ing. The results of this study prompted the importance of early treatment and regular follow-up of APN to avoid irreversible renal damage in children.