Renal Scan

There are many tests that can show the anatomy of the kidneys, but the nuclear medicine renal scan is unique because it also shows how the kidneys are functioning. This is valuable information that helps your physician make a proper diagnosis.

What To Expect

You will need to be at our imaging center about 1-1/2 hours for a regular renal scan, and 3 hours for a Captopril renal scan (Captopril is a blood pressure medication). During a Captopril renal scan, your kidneys will be scanned twice — once with no blood pressure medication and again after taking oral medication.

  • For a regular renal scan, you will be made as comfortable as possible on an imaging table. You will first be injected with a tracer material, and then a 1-hour scan of your kidneys will be taken immediately. Intravenous Lasix will be given 30 minutes into the scan.
  • For a Captopril renal scan, an initial blood pressure reading will be taken, and then a 30-minute scan of your kidneys will be taken immediately following a tracer injection. Intravenous Lasix will be given five minutes into the scan. After the first scan, 25mg of Captopril will be given orally. You will wait for about one hour for the Captopril to take effect, and then a second 30-minute scan of your kidneys will be taken. During this exam, your blood pressure will be monitored several times. When the exam is completed, the two scans will be compared to look for any change in kidney function after taking the Captopril. This can help your physician determine the best treatment for your hypertension.

After your renal scan, a Radiologist will review your images, prepare a written report, and discuss the results with your doctor. Your doctor will then explain the test results to you and discuss what further procedures, if any, may be needed.

A few things you need to know:

  • It is very important to remain still while you are being imaged, as movement may blur or distort your images.
  • There is no need to worry about the amount of radiation you will receive during the test. It is no more than what you would receive from similar x-ray procedures.
  • Be sure to tell your doctor if you are pregnant, think that you may be pregnant, or are a nursing mother.
  • Although adverse side effects are rare, you should tell the technologist if you feel lightheaded, nauseated, or if you have other symptoms during the exam.
  • The radioactive tracer will remain in your body for a short time and is cleared out through natural bodily functions. Drinking plenty of fluids before the exam and after the tracer injection helps eliminate the material more quickly.

After the test, you should be able to resume your normal daily activities immediately.

Patient Preparation

Nuclear Renal Scan

  • Do not take any diuretics (water pills) the day of your exam.
  • Drink at least 20 oz. of fluids up to 90 minutes before you arrive. No food 2 hours before test.

Captoprit Renal Scan

  • Do not take any blood pressure medications the day of your exam. If you are taking a blood pressure medication known as an ACE Inhibitor it will be necessary to speak to your physician regarding alternative blood pressure medications to be taken for 3 days prior to your exam.
  • Do not take any diuretics (water pills) the day of your exam.
  • Drink 20 oz. of fluids 90 minutes before you arrive.