Investigation

The initial evaluation starts with a urinalysis (dipstick and microscopic), including an evaluation for proteinuria and bacteriuria and a urine culture and sensitivity, if indicated. In addition, obtaining a baseline creatinine level is advisable to establish baseline renal function, particularly in severe cases.

Renal ultrasonography is recommended for both initial and follow-up examinations to evaluate renal anatomy, cortical thickness, the presence of hydronephrosis, and any structural abnormalities. Unfortunately, ultrasound lacks high sensitivity or specificity for detecting high-grade VUR.

The gold standard for evaluating VUR is direct cystography with voiding cystourethrogram (VCUG) as this provides detailed anatomical visualization, detects bladder diverticula, identifies ureteral duplications, demonstrates the extent of bladder wall trabeculation, and facilitates VUR grading.

In practice, the initial imaging method for a child experiencing their first febrile UTI typically involves renal ultrasound, with VCUG being recommended if sonography reveals abnormalities, a second UTI occurs, or if the patient presents with other high-risk factors such as bowel or bladder dysfunction.

Reference

1. Straus Takahashi M et al. Vesicoureteral reflux by contrast ultrasound, comparison with voiding and retrograde urethrocystography: A prospective accuracy study. J Pediatr Urol. 2024 Feb;20(1):133.e1-133.e9.