Your kidneys have to be able to filter the dye. Therefore, it is seldom performed if you have kidney failure. Before the procedure you may need a blood test to check that you do not have kidney failure.
Tell your doctor if you have any allergies, especially allergy to contrast dyes such as iodine.
You may be asked not to eat for several hours before the procedure. This ensures that your gut (intestines) is empty of food, which makes the X-ray pictures clearer.
You may be given some laxatives to take for a day or so before the procedure. The aim of this is to clear the intestines, which will make the X-ray pictures clearer.
You may be asked to sign a consent form to confirm that you understand the procedure.
If you have diabetes and take a medicine called metformin you may need to stop the metformin for two days prior to the procedure. This is because the combination of metformin and contrast dye may affect the kidneys. (You should discuss this, and how to manage your diabetes over this period, in more detail with your doctor.)
You will be asked to wear a gown and to lie on a couch. Contrast dye is then injected into a vein in your hand or arm. This may sting a little. The dye then starts to filter through the kidneys into the tubes which go from each kidney to the bladder (the ureters).
A series of X-ray pictures is then taken over your tummy (abdomen), usually every 5-10 minutes. You stay on the couch between each X-ray picture; however, you may be asked to get up to empty your bladder before the final X-ray picture is taken. The procedure usually takes about 30-60 minutes. Some pictures, however, may be taken hours later in certain circumstances.
You should be able to go home as soon as the procedure is finished. You can eat normally straight afterwards.
Contraindications: pregnancy (x-rays can negatively affect fetus development), x-ray examination with a barium suspension in the last four days, the inability of the patient to be stationary for even a short period of time, obesity (pictures can be fuzzy and uninformative).
Renal cell carcinoma (RCC)
Transitional cell carcinoma (TCC)
Anatomical variations, i.e. horseshoe kidney or a duplex collecting system
Obstruction (commonly at the pelvic-ureteric junction or PUJ and the vesicoureteric junction or VUJ)