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Medical Imaging

Nuclear Medicine > Exams & Procedures > Renal Lasix® Scan

This scan tests the level of function of each kidney, looking specifically for any sources of blockage.

This test involves the injection of a radioactive tracer intravenously, which will flow through the bloodstream and be filtered out by the kidneys. Pictures are taken continuously from the time the tracer is injected for one hour. At the end of the hour you are asked to use the washroom and a one-minute picture is taken. During the pictures the nuclear medicine doctor will give an injection of Lasix® through the intravenous line. Lasix® will make your kidneys work harder, increasing urine flow for the pictures.


  • You should drink plenty of water prior to the test and use the washroom immediately before the test begins.
  • Inform the technologist if you have any allergies to sulfa drugs.
  • Bring a list of all medications and supplements you take. This includes vitamins, herbal remedies, and holistic medications.
  • Do not bring children or pregnant women with you to the department. We do not want to expose them to unnecessary radiation.
  • Any of these procedures is subject to change according to the nuclear medicine physician. The duration of the tests is a rough estimate. Please be aware that the time may be lengthened if a scan has to be repeated, if emergency cases are brought to the department or due to unforeseen circumstances.

About the Procedure

  • The procedure takes about one hour.
  • A technologist will briefly explain the test to you and try to answer any questions you may have about the procedure.
  • A technologist will ask you a few questions about your medical history and medications.
  • You will be asked to go to the washroom immediately before the test is started.
  • You will be asked to lie down on an imaging bed.
  • A camera will be positioned below you (above you if you have had a kidney transplant).
  • The technologist will set up an intravenous line and give you an injection of a radioactive tracer into a vein.
  • Pictures are taken as the tracer is injected and for the next 60 minutes. It is very important that you do not move during these pictures.
  • The doctor will inject Lasix® through the intravenous line, usually 15 minutes into the scan.
  • Pictures will be taken for 60 minutes or until you have to urgently use the washroom.
  • After you use the washroom you will be repositioned above the camera and a one-minute picture will be taken.

Risks & Warnings

Allergy to sulfa drugs.

Possible Adverse Effects

Potential for allergic reaction to Lasix®.

You will have the urge to urinate for about one hour after the Lasix® injection.