How does a renal scan work?

One of the kidney’s main functions is to filter the bloodstream of waste toxins that are produced each day by the body’s metabolism. Certain small molecules are rapidly filtered by the kidney and pass out of the body in the urine. When having a renal scan, you are injected with a very small quantity of one of these small molecules that has had a radiotracer placed on it. A radiotracer is a substance that emits a small amount of energy similar to an X-ray which can be detected with a special camera. This radiotracer does not affect the biological properties of the small molecule. Using this technique, information concerning the blood flow to both kidneys and the function of both kidneys in producing urine can be measured.

Why am I having a renal scan?                                                                            

 The most common reason is to investigate kidneys that are not functioning properly. Another common reason is to investigate high blood pressure. There are many other reasons for having a renal scan and if you are unsure of why you are having the study staff or specialist will answer your questions.

What happens when I have a renal scan?

 You will be taken into a scanning room and you will lie on a bed with the gamma camera underneath the table. A small amount of radiotracer will be injected into your vein through a cannula. Scanning will commence immediately after the injection of tracer and will continue for about 30 minutes. You will then be asked to go to the toilet. The images are then processed and reviewed by the Doctor in Nuclear Medicine. Sometimes additional images are necessary

Are there any side effects?

No. You will not notice any side effects from the radiotracer injection.

How long will this test take?

The scan itself takes about 30 minutes to perform. With the possibility of additional imaging allow between 60 and 90 minutes from when you first arrive.

What are the preparations that I need to take?

3 cups of water must be taken a half hour prior to the scan. You may eat or drink whatever you feel like. No medications will interfere with the renal scan.

Are there any restrictions during or after the scan?

Yes. You should not nurse a small child from the time that you receive the first injection until 12 hours after you have completed the study.

If you are breast feeding, pregnant or think that you might be pregnant, please tell the staff BEFORE the first injection.

What should I do following the test?

We ask that you:

  1. Keep yourself well hydrated for the next 24 hours. A substantial amount of the Tc99m injection will pass out through your urine.
  2. Keep your distance from pregnant woman or children.
  3. If you are seeing your doctor or any other health professional immediately after your scan please notify them that you are still a source of radiation.
  4. We ask that you do not schedule any other appointments for yourself for the rest of the day.



9716 3600


 8042 3000


9911 6800

Five Dock

8705 8300


9598 0100


8228 9000

North Strathfield

8282 8100

North Sydney (Mater Imaging)

9955 4466
Go to top