Renal Scan

What is it?

A Nuclear Medicine Renal Scan is performed using a special radioactive material that, when injected into the blood stream is filtered out by the kidneys. Once collected in the kidneys, pictures of the kidneys can be made.

Nuclear Medicine scans are performed using very small amounts of radioactive material. The radioactive material is usually bound to other non-radioactive elements. These combined elements are called "radionuclide". The radionuclide emit energy called "photons". Radionuclide can be directed to many organs and systems in the body. Once a radionuclide is distributed in an organ or system, the photon energy is collected by a "Gamma Camera". The Gamma Camera detects the pattern of distribution of the radionuclide in the body and sends this information to a computer. The computer processes the information and displays the information in the form of a picture.

Nuclear Medicine exams differ from other x-ray procedures because the energy (x-rays and photons) come from different sources. X-ray energy is created by the x-ray tube and pass through the body. Another major difference is that Nuclear Medicine exams best demonstrate body physiology (system function), whereas x-rays show anatomical detail.

What will happen to me?

The Nuclear Medicine Technologist will inject a special radionuclide into your vein, usually in your arm. The blood will distribute the radionuclide throughout your body and will be filtered out slowly by the kidneys. After the injection, it takes 3 - 4 hours before the radionuclide is adequately distributed in the kidneys and a picture can be taken. To start the scan, the technologist will position you on a flat table and will place you under the Gamma Camera. The Gamma Camera will be very close to you to obtain the best picture.

How long will it take?

The visit for the injection of the radionuclide takes 10 - 15 minutes. After the injection, you will need to return to the Nuclear Medicine Department after 3 - 4 hours for the first picture. Once the actual scan is started it takes 30 - 45 minutes to complete.

What will I feel, will it hurt?

You may feel a slight pinprick in the vein of your arm when the radionuclide is injected. You will not feel any effects from the radionuclide injection. When your scan is begun, you will need to lay flat on a table. You will need to lay very still while the scan is being performed so that the best picture can be made. You will not feel any effects from the Gamma Camera. It does not create radiation, it only detects the radiation coming from your body. The Gamma Camera is a large machine that collects the emitted photons from the radionuclide but produces very little sound. The Gamma Camera must be very close to you and will be moved over your body to obtain the pictures. The radiation will totally disappear from your body in about 48 hours. The radiation exposure you receive for the scan is no more than from a routine x-ray procedure.

What will the test show?

The radionuclide is distributed throughout your kidneys. If any areas in the kidneys collect more or less of the radionuclide this will be seen on the pictures. The renal scan can also show the size, shape and location of the kidneys.

How do I get ready?

You can eat as you normally do. After the injection, you should drink several glasses of fluid over the next two (2) hours and empty your bladder frequently. You should remove any metal such as belt buckle, earrings, necklaces, keys, etc., since these will interfere with the pictures.

Reviewed: May 2005