Which investigation is known as the gold standard for diagnosing vesicoureteral reflux?

The micturating cystourethrogram (MCUG) is recognized as the gold standard for diagnosing vesicoureteral reflux (VUR). This radiological procedure involves filling the bladder with a contrast agent and taking X-ray images while the patient voids. It directly visualizes the urinary tract, allowing for the assessment of how well urine flows from the bladder into the ureters and kidneys.

The primary advantage of MCUG lies in its ability to provide clear, real-time images of the urinary tract during micturition. This allows for the precise identification of any reflux of urine back into the ureters, which is essential for making a definitive diagnosis of VUR. Identifying the severity of the reflux is critical for determining subsequent management and treatment options for the child.

Other methods like ultrasound, while useful for assessing kidney structures and detecting hydronephrosis associated with VUR, do not provide the dynamic evaluation necessary for a definitive diagnosis. CT urography, although it offers exceptional anatomical detail, carries additional radiation exposure and is not typically used as the initial diagnostic tool for VUR in children. A bladder diary primarily aids in recording patterns of voiding and is helpful in assessing urinary habits but does not visualize the anatomical or functional aspects