Investigating febrile UTI in infants: is a cystogram necessary?

Area of Science:

• Pediatric Nephrology
• Diagnostic Imaging
• Urology

Background:

• Current guidelines recommend ultrasound (US), micturating cystourethrogram (MCUG), and dimercaptosuccinic acid (DMSA) scans for infantile febrile urinary tract infections (UTIs).
• The utility and necessity of MCUG in the diagnostic workup of a first febrile UTI in infants are debated.

Purpose of the Study:

• To evaluate the indications and benefits of performing MCUG in infants presenting with their first febrile UTI.
• To determine if MCUG is essential in all cases or if its use can be more selectively applied based on other imaging findings.

Main Methods:

• A retrospective cohort study involving 427 infants with a first febrile UTI.
• Infants were categorized into two groups based on renal US findings: normal (Group A, n=354) and abnormal (Group B, n=73).
• DMSA scan findings were correlated with MCUG results to assess for vesicoureteric reflux (VUR) and renal scarring.

Main Results:

• In infants with normal US (Group A), only 6% showed DMSA scarring and low-grade VUR.
• In infants with abnormal US (Group B), 32% had DMSA scarring and predominantly high-grade VUR.
• Among infants with non-scarred kidneys, 73% exhibited dilating reflux; 4 infants required surgery, while 423 were managed conservatively.

Conclusions:

• Recommend US and DMSA for all infantile febrile UTI cases.
• Reserve MCUG for infants with normal US but abnormal DMSA findings.
• Perform MCUG in all cases with an abnormal US, regardless of DMSA scan results; further randomized prospective studies are warranted.