Wallace Sowdhamini S, Zhang Wei, Mahmood Nadia F, Williams Jennifer L, Cruz Andrea T, Macias Charles G, Quinonez Ricardo A, Orth Robert C
1 Section of Pediatric Hospital Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, TX.
2 Department of Pediatric Radiology, Texas Children's Hospital and Baylor College of Medicine, 6701 Fannin St, Ste 470.01, Houston, TX 77030-2399.
AJR Am J Roentgenol. 2015 Oct;205(4):894-8. doi: 10.2214/AJR.15.14424.
The purpose of this study is to determine the performance of renal ultrasound for detecting vesicoureteral reflux (VUR) and obstructive uropathies in infants younger than 2 months with a febrile urinary tract infection (UTI).
We performed a retrospective cohort study of infants younger than 2 months with fever and culture-proven UTI presenting from July 1, 2008, through December 31, 2011, with renal ultrasound and voiding cystourethrogram (VCUG) performed within 30 days of UTI diagnosis. Two pediatric radiologists independently reviewed the renal ultrasound and VCUG findings. Results of the renal ultrasound were deemed abnormal if collecting system dilation, renal size asymmetry, collecting system duplication, urothelial thickening, ureteral dilation, or bladder anomalies were present. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of renal ultrasound were calculated using VCUG as reference standard.
Of the 197 patients included (mean [SD] age, 33 [ 15 ] days; male-to-female ratio, 2:1), 25% (n = 49) had VUR grades I-V, with 16% (n = 31) having VUR grades III-V and 8% (n = 15) having VUR grades IV-V. For grades I-V VUR, sensitivity was 32.7% (95% CI, 20.0-47.5%), specificity was 69.6% (95% CI, 61.5-76.9%), PPV was 26.2% (95% CI, 15.8-39.1%), and NPV was 75.7% (95% CI, 67.6-82.7%). For grades III-V VUR, sensitivity was 51.6% (95% CI, 33.1-69.9%), specificity was 72.9% (95% CI, 65.5-79.5%), PPV was 26.2% (95% CI, 15.8-39.1%), and NPV was 89.0% (95% CI, 82.5-93.7%). For grades IV-V VUR, sensitivity was 86.7% (95% CI, 59.5-98.3%), specificity was 73.6% (95% CI, 66.6-79.9%), PPV was 21.3% (95% CI, 11.9-33.7%), and NPV was 98.5% (95% CI, 94.8-99.8%). No obstructive uropathies were diagnosed by VCUG in patients with normal renal ultrasound findings.
In infants younger than 2 months, a normal renal ultrasound makes the presence of grades IV and V VUR highly unlikely but does not rule out lower grades of VUR.
本研究旨在确定肾脏超声对2个月以下发热性尿路感染（UTI）婴儿膀胱输尿管反流（VUR）和梗阻性尿路病的诊断效能。
我们对2008年7月1日至2011年12月31日期间出现发热且经培养证实患有UTI的2个月以下婴儿进行了一项回顾性队列研究，在UTI诊断后30天内进行了肾脏超声和排尿性膀胱尿道造影（VCUG）检查。两名儿科放射科医生独立审查肾脏超声和VCUG检查结果。如果存在集合系统扩张、肾脏大小不对称、集合系统重复、尿路上皮增厚、输尿管扩张或膀胱异常，则认为肾脏超声结果异常。以VCUG作为参考标准，计算肾脏超声的敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）。
纳入的197例患者（平均[标准差]年龄为33 [15]天；男女比例为2:1）中，25%（n = 49）患有I-V级VUR，其中16%（n = 31）患有III-V级VUR，8%（n = 15）患有IV-V级VUR。对于I-V级VUR，敏感性为32.7%（95%CI，20.0 - 47.5%），特异性为69.6%（95%CI，61.5 - 76.9%），PPV为26.2%（95%CI，15.8 - 39.1%），NPV为75.7%（95%CI，67.6 - 82.7%）。对于III-V级VUR，敏感性为51.6%（95%CI，33.1 - 69.9%），特异性为72.9%（95%CI，65.5 - 79.5%），PPV为26.2%（95%CI，15.8 - 39.1%），NPV为89.0%（95%CI，82.5 - 93.7%）。对于IV-V级VUR，敏感性为86.7%（95%CI，59.5 - 98.3%），特异性为73.6%（95%CI，66.6 - 79.9%），PPV为21.3%（95%CI，11.9 - 33.7%），NPV为98.5%（95%CI，94.8 - 99.8%）。肾脏超声检查结果正常的患者中，VCUG未诊断出梗阻性尿路病。
在2个月以下的婴儿中，肾脏超声检查结果正常极不可能存在IV级和V级VUR，但不能排除较低级别的VUR。
