Final answer:
IVP requires a contrast medium to better visualize the bladder and is used to examine the urinary tract structure and function through enhanced radiographic contrast.
Step-by-step explanation:
IVP, or intravenous pyelogram, requires a contrast medium so they can visualize the bladder better. This diagnostic imaging technique allows healthcare professionals to view the structure and function of the urinary tract, including the kidneys, ureters, and bladder. A contrast medium, usually containing iodine, is injected into the patient's veins, which then travels through the bloodstream to the kidneys and is excreted into the urine. This enhances the radiographic contrast in the images taken during the procedure, making it easier to identify abnormalities or issues within the urinary tract.