IVP, Intravenous Pyelography

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Indications for IVP Examination:
Flank Pain, blood in the urine, urinary frequency, pain on urination, suspected renal stone, or renal tumor.

Patient Preparation:
Bowel cleansing before exam is preferred because stool in bowel tends to obscure the kidneys.

Precautions for IVP Test:
The status of kidneys is evaluated (by obtaining serum BUN and creatinine) because the contrast material (dye) used in the IVP can cause further kidney damage. The IVP examination may be postponed if there is evidence of renal impairment.

Allergy to iodinated contrast (dye) may take the form of hives, skin rash, itching, running nose, sneezing, bronchospasm, wheezing, laryngeal edema, pulmonary edema, as well as more severe life threatening reactions. The incidence of allergic reaction has decreased considerably with the advent on the newer non-ionic contrast agents.

If there is a pre-existing allergy to contrast material (dye), the patient may be pre-treated with Benadryl and Prednisone and then given non-ionic IV contrast.

Please inform your doctor if you have had these reactions to contrast material in the past.

Glucophage precaution:
Diabetic patients taking Glucophage are advised to stop glucophage 24 hrs prior to and resume 48 hours after IVP to avoid risk of lactic acidosis related to contrast renal impairment. This precaution has been liberalized by some centers to merely holding (stopping) the glucophage at the time of the IVP and resuming the glucophage 48 hrs after the IVP.

Procedure:
Intravenous line is started in the antecubital (in front of the elbow) vein and 50 to 100 cc of iodinated contrast (dye) is injected into the vein. X-ray films of the abdomen are taken at various times after (for example, 1,2,3,5,10,20 minutes after injection). Some patients notice a "warm sensation" and a metallic taste from the iodinated contrast. This goes away after a few minutes.

Description of Xray Process:
X-rays are taken with the patient on a table and an X-ray machine above the patient. The X-ray film is placed under the patient in a special holder in the table. The X-ray beam travels from the X-ray tube through the patient and makes an image on the film under the patient.

Possible findings on the IVP:
Kidney Stones: The IVP shows if there is a stone in the kidney or ureter (tube connecting the kidney with the bladder) and if there is any blockage. Small stones usually pass through into the bladder spontaneously with time with IV hydration and painkillers. If the stone is large and fails to pass through into the urine, then retrograde pyelogram (performed by placing a tube into the bladder and the ureter) and retrieval of the stone may be necessary. The urologist performs this in the operating room under general anesthesia. In the event the retrograde pyelogram cannot be performed, the urologist may request an interventional radiologist to place a tube through the skin and into the kidney to drain the obstruction. This is done with IV sedation in the radiology department.

Renal Masses: The IVP may indicate the presence of a renal mass or cyst. A renal sonogram will be recommended by the radiologist to more clearly define the mass. The sonogram will show whether a mass is a benign renal cyst (which are very common) or whether the mass is a solid tumor in which case further evaluation with CAT scan, MRI, or angiogram.

Hypertension (high blood pressure): An IVP is not recommended for the evaluation of hypertension since MAG3 renogram with Captopril is a much better screening test. MRI of kidneys and renal arteries are also being increasingly used as well.

IVP showing large stone obstructing the right kidney (arrows)