A voiding cystourethrogram (VCUG), also known as micturating cystourethrogram (MCU) is a radiological investigation for examination of urinary tract system. The study is used to visualize the urethra, urinary bladder and about the possibility of vesicoureteral reflux (VUR).
The study is conducted under antibiotic cover and in fluoroscopic machine.
VCUG gives an idea about any abnormality related to bladder size and shape (neurogenic bladder, bladder diverticula, bladder mass etc.). It also identifies urethral problems, such as a blockage along the path of the urine (posterior urethral valve, urethral stricture etc.). VCUG helps in making a diagnosis of vesicoureteral reflux (VUR) in which the urine goes back(reflux) towards kidney. VCUG is the only confirmatory imaging for the diagnosis of vesicoureteral reflux.
There is a mild risk of urinary tract infections so it should always be done under antibiotic cover and after treating any preexisting urinary tract infections.
There is some risk due to exposure to radiation, however the amount of radiation used in VCUG is small and is not considered dangerous.