As knowledge on vesicoureteral reflux (VUR) and the limited effectiveness of its treatment has increased, several guidelines have been updated, and no longer recommend extensive routine imaging of all children with urinary tract infection (UTI). 

We determined the possible consequences of following the most widely used guidelines for imaging children with UTI, in a retrospective cohort of children treated for UTI in Turku University Hospital in the years 2000-2009. Using the same cohort, we identified factors associated with abnormal imaging and UTI recurrence after a first febrile UTI. We also performed a meta-analysis aiming to determine the value of ultrasonography in identifying patients with VUR after UTI. 

We found that following the guidelines issued by the National Institute for Health and Care Excellence may lead to missing a substantial number of patients with significant urological anomalies, whereas following the guidelines issued by the American Academy of Pediatrics may lead to fewer patients being missed. Both strategies may lead to avoiding a significant number of unnecessary imaging studies. We identified several factors associated with abnormal imaging and UTI recurrence, and determined a risk score system for predicting the risk for VUR and high-grade VUR. This system had high sensitivity in detecting high-grade VUR in our population. In a meta-analysis of 14 studies, we found that ultrasonography is not sufficiently accurate in predicting the presence or absence of VUR. 

The optimal imaging strategy for imaging children with UTI is controversial, and depends ultimately on the significance of VUR and the effectiveness of its treatment.