Verified answer

voiding cystourethrogram (VCUG)

It is a urodynamic test.

Video Urodynamics

Urodynamic tests may be performed with or without equipment to take pictures of the bladder during filling and emptying. The imaging equipment may use x rays or sound waves. If x-ray equipment is used, the bladder will be filled with a contrast medium that will show up on the x ray instead of the warm water. The pictures and videos show the size and shape of the urinary tract and help your doctor or nurse understand your problem.

http://kidney.niddk.nih.gov/kudiseases/pubs/urodyn...