Early Imaging for First Febrile Urinary Tract Infection Tied to False Positives

TUESDAY, Feb. 24, 2026 (HealthDay News) — Ultrasounds performed too early during hospitalization for first febrile urinary tract infection (fUTI) are more likely to produce false positives in young children, according to a study published online Feb. 17 in Hospital Pediatrics.

Melanie C. Marsh, M.D., from Advocate Children”s Hospital in Park Ridge, Illinois, and colleagues examined practice patterns of timing of renal/bladder ultrasonography and assessed the significance of abnormal findings relative to fever. The analysis included 294 children aged 2 to 24 months when hospitalized for first fUTI (2018 through 2022).

The researchers found that 95.9 percent of children had an ultrasonography (90.8 percent during hospitalization), with 62.8 percent performed early (<24 hours) and 28.7 percent performed late (>24 hours). Abnormalities were more often seen in early (64.4 percent) versus late (40.7 percent) ultrasonography. Uroepithelial thickening was more frequent among early (18.6 percent) than late (4.9 percent) ultrasonography. In 72 children, ultrasonography results prompted a voiding cystourethrogram (VCUG). In the early ultrasonography group, 54.7 percent of VCUG findings were normal versus 46.2 percent in the late group. 

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

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