Imaging investigation after urinary tract infection in childhood: narrative review of current recommendations

Background and Objective: Urinary tract infections (UTIs) are one of the most common bacterial infections in children. The imaging exams that take place after the occurrence of UTI have the main goal of detecting congenital anomalies of the kidney and urinary tract (CAKUT). The value of imaging investigation relies on guiding the management of the patient and directing measures to prevent recurrent infections and to avoid possible kidney scars. Currently, there has been a general trend to restrict the number of imaging tests performed in clinical practice as can be seen in the most important guidelines regarding the management of patients with febrile UTI. The guidelines from the American Association of Pediatrics (AAP), the National Institute for Health and Care Excellence (NICE), and the European Association of Urology (EAU)/European Society for All Pediatric Urology (ESPU) made recommendations in this regard. We believe that the critical discussion about the advantages and disadvantages of the different guidelines and protocols proposed is important for pediatricians and nephrologists and helps to define the best approach for patients. In this matter, this review aimed to provide a critical view of imaging investigation methods and guidelines after UTIs in pediatric patients. Methods: The authors performed a non-systematic search in PubMed, Cochrane, Scopus, SciELO and in renowned books from the subjects of pediatric nephrology and pediatric urology published up to August 5th, 2021, and critically selected and independently reviewed articles written mainly in English or Portuguese to produce this narrative review. Key Content and Findings: In this narrative review, shortcomings of different imaging guidelines and examinations after urinary tract infections in children are explored, while the principles and advantages of distinct imaging methods are highlighted. We find that, while an initial renal and bladder ultrasonography is of great value, more invasive exams need to be carefully selected to identify patients at risk for further complications whilst minimizing distress and other consequences to the child. Conclusions: A renal ultrasonography with good quality of images and examined by an expert is generally recommended as initial screening after UTI. Additional imaging exams depend on findings provided by renal ultrasonography. but the exam is of low