Retrograde Pyelogram for Kidney Stones
The retrograde pyelogram uses a dye to find out whether a kidney stone or something else is blocking your urinary tract. During the test, your doctor will insert a thin, lighted tube (cystoscope) into the urethra, which carries urine out of the body from the bladder. He or she will then put a catheter through the cystoscope and into a ureter, which carries urine from the kidney to the bladder. Dye is injected through the catheter, and X-rays are taken.
You will probably need a local or regional anesthetic with this procedure.
Your doctor may do this test if an intravenous pyelogram (IVP) does not help with the diagnosis. In an IVP, the dye is injected through a vein in your arm.
Why It Is Done
You may have a retrograde pyelogram if:
- The IVP does not show a reason for your urinary symptoms.
- The IVP cannot be done because of kidney problems such as chronic kidney disease.
- You are allergic to the iodine-based dye (contrast material) used in the IVP.
Pregnant women normally do not have this test, because the X-rays may harm the unborn baby.
Findings of the retrograde pyelogram may include the following.
The kidneys, ureters, and bladder appear normal.
The flow of the dye (contrast material) is blocked, either by a stone or another urinary problem.
What To Think About
The retrograde pyelogram provides the same information as an intravenous pyelogram (IVP). But the retrograde pyelogram can be used even if you are allergic to the dye. This test does not risk making existing kidney damage worse.
Unlike the IVP, the retrograde pyelogram requires an anesthetic and uses a catheter inserted into the urinary tract.