Medical Content Created by the Faculty of the
Harvard Medical School
You wear a hospital gown and lie on a table in the x-ray department. A part of your genital area is cleaned with soap on a cotton swab. Then a soft, bendable rubber tube called a urinary catheter is inserted into your bladder, usually by a nurse. The tube is first coated with a slippery jelly and then pushed gently through the opening of the urethra (at the end of the penis for men and near the opening of the vagina for women).
You will feel some pressure while the tube slides into the urethra. Once it is in place, a tiny balloon on the end of the tube is filled with air to hold it in position. The other end (about 6 inches of tubing) hangs outside of your vagina or penis. The doctor uses this tube to fill your bladder with fluid containing a dye that shows up on x-rays. You will feel pressure in your bladder as it begins to expand.
To create a clear picture, your bladder needs to be filled with as much fluid as it can hold. You will probably feel a very strong urge to urinate. A few pictures are taken with the bladder completely full, and then the small catheter balloon is emptied and the tube is pulled out. You are given a urinal container or a bedpan and asked to urinate while you are still on the table under the x-ray camera. Several pictures are taken while your bladder is emptying. Many patients find this part of the test embarrassing, but you can be reassured that it is a routine part of this common test, something the technicians in this test lab see on a regular basis.