Study finds early imaging after pediatric UTIs may do more harm than good: Study

The research, led by Melanie Marsh, M.D., assistant professor at Wake Forest University School of Medicine in North Carolina and clinician at Advocate Children’s Hospital in Illinois, found that the routine step of performing renal and bladder ultrasounds too soon, while a child still has a fever or shortly after fever resolves, could lead to “false positives” of abnormal findings. These early findings could then prompt additional invasive testing that may not be necessary, along with additional follow-up appointments, adding angst and costs for the children and their families.

“We’re due for updated guidance for physicians surrounding imaging following a UTI diagnosis. In the meantime, we wanted to figure out the best time for a renal and bladder ultrasound,” Marsh said, adding that the recommendation from the American Academy of Pediatrics is to ensure patients ages 2 months to 2 years old receive an ultrasound to check for any anatomic abnormalities in the kidneys, bladder or urinary tract.

“It’s common for patients to receive this ultrasound while they’re in the hospital, but we wanted to understand if there’s a difference between getting it the day of diagnosis or closer to discharge,” Marsh said.

Researchers examined medical record data of about 300 children hospitalized between 2018 and 2022 at Advocate Children’s Hospital in Illinois, Atrium Health’s Levine Children’s and Wake Forest Brenner Children’s hospitals in North Carolina, Aurora Children's Health in Wisconsin and Nationwide Children’s Hospital in Ohio.

They found that ultrasounds performed within the first 24 hours of a child’s last fever were significantly more likely to show abnormal results, many of which then resolved and were likely related to the temporary fever.

“Ultrasounds performed later in the hospital stay had less risk of false positives,” Marsh said. “And that means less chance of additional and invasive tests.”

If an initial ultrasound indicates abnormal results, the next step is a voiding cystourethrograms (VCUGs), which involve catheterization and radiation exposure.

“Families are already under tremendous stress when their child is hospitalized,” Marsh said. “Our findings suggest that a short delay in imaging may help avoid unnecessary testing while still ensuring children receive safe, appropriate care.”

The results also showed waiting until a fever resolved and closer to hospital discharge did not ultimately prolong the hospital stay.

“This study helps clinicians strike the right balance between avoiding unnecessary procedures and ensuring serious conditions are not missed,” said Marsh. “It gives pediatricians practical, evidence‑based guidance they can use in real‑world hospital settings.”

Reference:

Melanie C. Marsh, Lauren Abbas, Timing of Renal and Bladder Ultrasound After First Febrile Urinary Tract Infection: A Hospitalist Dilemma, Hospital Pediatrics, https://doi.org/10.1542/hpeds.2025-008534