This exam may be done in a hospital or in a doctor’s office by a radiologist or x-ray technician. To begin, dye is injected right into the kidneys. This allows them to be seen more clearly on x-ray.
- An ultrasound probe or a CT scan will be used to first find the kidneys. Then, the skin over the kidney will be numbed and a needle is passed to the kidney. Dye is inserted to outline the renal collection system. (This is the part of the urinary tract that drains urine between the kidney and bladder.) After this, x-ray images are taken to look for problems.
- More often, a patient has a tube that drains urine from the kidney (nephrostomy tube). Dye is injected through this tube into the urine collecting system. Then x-rays are taken and reviewed.
While pyelography is mostly safe, some people have a reaction to iodine in the dye. Minor reactions may be hot flashes, nausea and vomiting. These are usually treated with antihistamines. (Drugs that reduce the body's allergic response.) Very rarely, an allergic reaction could be serious. For example, breathing trouble, low blood pressure, mouth or throat swelling and even cardiac arrest can occur.
It helps to talk with your provider about your allergy history before you begin.
Exposure to radiation is low during this test. Still, a patient who is or may be pregnant should tell their doctor. A fetus should be protected from exposure when possible.