What is it?
A Nuclear Medicine Renogram is performed using a special radioactive material that, when injected into the blood stream shows the kidney blood supply and filtering action of the kidneys.
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 "radionuclides". The radionuclides emit energy called "photons". Radionuclides 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. The photon energy is emitted from the radionuclide injection and passes out of 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 by the kidneys. To start the scan, the technologist will position you on a flat table close to the gamma camera. The gamma camera will be very close to you to obtain the best picture. After you are in position, the technologist will inject the radionuclide in your vein and immediately begin taking rapid pictures.
How long will this test take?
It will take about 15 minutes to prepare you for the exam once you arrive in the Nuclear Medicine Department. Once the actual scan is started, it takes 60 minutes to complete. (Captopril Exams are done in two parts, one in two parts, one in the morning and one in the afternoon.)
What will 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 the injected radionuclide. 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. The radiation from the radionuclide will totally disappear from your body in about 24 hours. The radiation exposure you receive for the renogram is no more than from a routine x-ray procedure.
What will the test show?
The renogram shows the blood supply (arteries) to the kidneys as well as the size and location of the kidneys. As the kidneys filter the radionuclide out of the blood, the kidney filtering function is seen also.
How do I get ready?
You may be instructed by your doctor to stop taking diuretics and/or high blood pressure medications for two days before the exam. You can eat as you normally do. 90 minutes before your exam, you will need to drink 16 - 32 oz of water. Just before the start of your exam, you will need to empty your bladder as much as possible. You should remove any metal such as belt buckle, and keys, etc. since these will interfere with the pictures.
Reviewed: November 2005