Urinary tract infection: is there a need for routine renal ultrasonography?

Abstract

Aims: To assess the yield of routine renal ultrasound (RUS) in the management of young children hospitalised with first uncomplicated febrile urinary tract infection (UTI).

Methods: All children aged 0-5 years who had been hospitalised over a two year period with first uncomplicated febrile UTI in a medium size institutional regional medical centre were included. Children with known urinary abnormalities and/or who had been treated with antibacterial agents within seven days before admission were excluded. All included children underwent renal ultrasonography during hospitalisation and voiding cystouretrography (VCUG) within 2-6 months. The yield of RUS was measured by its ability to detect renal abnormalities, its sensitivity, specificity, and positive and negative predictive values for detecting vesicoureteral reflux (VUR), and by its impact on UTI management.

Results: Of 255 children that were included in the study, 33 children had mild to moderate renal pelvis dilatation on RUS suggesting VUR, of whom only nine had VUR on VCUG. On the other hand, in 36 children with VUR on VCUG the RUS was normal. The sensitivity, specificity, positive predictive value, and negative predictive value of abnormal RUS for detecting VUR were 17.7%, 87.6%, 23.5%, and 83.2% respectively. In none of the patients with abnormal RUS was a change in the management at or following hospitalisation needed.

Conclusion: Results show that the yield of RUS to the management of children with first uncomplicated UTI is questionable.

Figure 1

Results of imaging studies. *Also found to have double collecting system and severe hydronephrosis on RUS.