Imaging strategies in pediatric urinary tract infection

Abstract

This article is focused on the controversial topic of imaging strategies in pediatric urinary tract infection. A review of the recent literature illustrates the complementary roles of ultrasound, diagnostic radiology and nuclear medicine. The authors stress the key role of ultrasound which has recently been debated. The commonly associated vesicoureteric reflux has to be classified as congenital or secondary due to voiding dysfunction. A series of frequently asked questions are addressed in a second section. The proposed answers are not the product of a consensus but should rather be considered as proposals to enrich the ongoing debate concerning the evaluation of urinary tract infection in children.

Diagnostic role of initial renal cortical scintigraphy in children with the first episode of acute pyelonephritis

“…Abnormal initial DMSA scan in our study could help to detect infected kidneys at risk of subsequent scarring and those children who are at risk of future complications [20,24]. The early definition of such a high-risk group may be of interest, particularly in distant geographical areas in our country, where compliance with treatment and follow-up may be low.…”

“…During our participation in the consensus on renal cortical scintigraphy in children with UTI, we referred to the absence of any strategy in our country on the use of initial cortical scintigraphy [13]. Although the role of DMSA scintigraphy in the diagnosis of APN has been a subject of debate and controversy for many years [18], presently it has become important and challenging given the increasing number of children with their first febrile UTI [19,20].…”

Value of comprehensive renal ultrasound in children with acute urinary tract infection for assessment of renal involvement: comparison with DMSA scintigraphy and final diagnosis

“…Beside the restrictions of DMSA in small kidneys, this phenomenon may also be due to the better US conditions in these very young patients (e.g., higher resolution transducers applicable, less disturbing fat and gas, etc.). Multi-detector CT (MDCT) and MRI have also been shown to be sensitive methods for the depiction of upper UTI in experimental and in clinical studies [4,21,22,31,32]. Their sensitivity and specificity were reported to be 86.8% and 87.5% for CT and 89.5% and 87.5% for MRI, compared to histopathology [4].…”

“…We acknowledge that-in a child with known normal urinary tract anatomy and a clinically evident diagnosis-early imaging may be unnecessary. But initial US is helpful in all other cases for demonstration of urinary tract anatomy, detection of renal involvement, or early recognition of a complicated course such as abscess formation or pyonephrosis [39]. Children with equivocal or unreliable US examinations (e.g., due to complicated conditions or insufficient cooperation) or mismatch between clinical, laboratory, and US results will need additional imaging by DMSA or-particularly in patients with suspected complications-MDCT/MR.…”

“…UTI is the second most common bacterial infection in children and occurs in as many as 5% of girls and approximately 0.5% of boys, with a maximum prevalence in male infants and school age girls [22]. VUR and renal scarring are major concerns, especially during the first years of life [23].…”