New Criteria for Renal Scintigraphy After Urinary Tract Infection: Are those Adequate?

Resumo

Introduction: Criteria for imagiological studies following urinary tract infections (UTI) are frequently updated, including for renal scintigraphy with dimercaptosuccinic acid (DMSA), the gold standard method for renal scars detection. Until 2020, in the authors’ hospital, every patient with febrile UTI underwent follow‐up scintigraphy. This study aims to analyze the results of post‐UTI DMSA scintigraphy based on current performance criteria, which are atypical UTI below three years old, recurrent UTI and altered renal and bladder ultrasound (RBUS).
Methods: Retrospective analysis of patients under 16 years of age who underwent post‐UTI DMSA scintigraphy between 2011 and 2020. Demographical, clinical, analytical and imagiological data were collected.
Results: Of the 231 patients considered, 60% were female, and the median age was 14 months. Escherichia coli was the most commonly identified bacteria. Atypical UTI under three years old occurred in 28 patients (12%), recurrent UTI in 50 (22%) and RBUS abnormalities in 18 (7%). Altered DMSA scintigraphy was identified in 39 patients (17%), with these alterations correlating with the new criteria (odds ratio 2.7 (1.3‐5.4)). Altered DMSA scintigraphy was more frequent in patients with recurrent UTI or altered RBUS, but not with atypical UTI under three years old. Alterations in DMSA scintigraphy were found in 18 patients who did not meet new criteria (12%).
Conclusion: The new criteria are associated with a higher incidence of altered DMSA scintigraphy but also lead to unidentified alterations. Follow‐up studies are necessary to understand the clinical consequences for patients who, under the new criteria, would not undergo DMSA scintigraphy.