You will feel a slight pin prick when the technologist inserts the needle into your vein for the intravenous line. You may feel a cold sensation moving up your arm during the radiotracer injection. Generally, there are no other side effects. With some procedures, the technologist may place a catheter into your bladder. This may cause temporary discomfort.
It is important to remain still during the exam. Nuclear imaging causes no pain. However, having to remain still or in one position for long periods may cause discomfort. Unless your doctor tells you otherwise, you may resume your normal activities after your exam. A technologist, nurse, or doctor will provide you with any necessary special instructions before you leave.
The small amount of radiotracer in your body will lose its radioactivity over time through the natural process of radioactive decay. It may also pass out of your body through your urine or stool during the first few hours or days after the test. Drink plenty of water to help flush the material out of your body. For more information on what you will experience during and after a CT scan, see Computed Tomography. A radiologist or other doctor specially trained in nuclear medicine will interpret the images and send a report to your referring physician.
If your doctor has ordered a diagnostic CT, a radiologist with specialized training in interpreting CT exams will send a report to your referring physician. Nuclear medicine procedures can be time consuming. It can take several hours to days for the radiotracer to accumulate in the area of interest. Plus, imaging may take up to several hours to perform. In some cases, newer equipment can substantially shorten the procedure time. However, nuclear medicine scans are more sensitive for a variety of indications.
The functional information they yield is often unobtainable using other imaging techniques. Altered blood sugar or blood insulin levels may adversely affect the test results of diabetic patients or patients who have eaten a few hours prior to the exam. The radiotracer decays quickly and is effective for only a short time.
Therefore, it is important for you to be on time for your appointment and to receive the radioactive material at the scheduled time.
Late arrival for an appointment may require you to reschedule the procedure. Please type your comment or suggestion into the text box below. Note: we are unable to answer specific questions or offer individual medical advice or opinions.
Please contact your physician with specific medical questions or for a referral to a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you can search the ACR-accredited facilities database.
This website does not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region. Web page review process: This Web page is reviewed regularly by a physician with expertise in the medical area presented and is further reviewed by committees from the Radiological Society of North America RSNA and the American College of Radiology ACR , comprising physicians with expertise in several radiologic areas.
Outside links: For the convenience of our users, RadiologyInfo. Toggle navigation. What are some common uses of the procedure? What does the equipment look like? How does the procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. Which test, procedure or treatment is best for me? You may wear a gown during the exam or be allowed to wear your own clothing.
A computer creates the images using the data from the gamma camera. PET scans only use radiotracer injections. Doctors perform nuclear medicine exams on outpatients and hospitalized patients.
Total scanning time is usually about 30 minutes. However, having to remain still or in one position for long periods may cause discomfort If you have a fear of closed spaces, you may feel anxious during the exam.
Benefits Nuclear medicine exams provide unique information that is often unattainable using other imaging procedures. This information may include details on the function and anatomy of body structures. Nuclear medicine supplies the most useful diagnostic or treatment information for many diseases. A nuclear medicine scan is less expensive and may yield more precise information than exploratory surgery.
By identifying changes in the body at the cellular level, PET imaging may detect the early onset of disease before it is evident on other imaging tests such as CT or MRI. Risks Because nuclear medicine exams use only a small dose of radiotracer, they have a relatively low radiation exposure. This is acceptable for diagnostic exams.
Thus, the potential benefits of an exam outweigh the very low radiation risk. Positron emission tomography During a positron emission tomography PET scan, you lie on a narrow table that slides into a doughnut-shaped hole. PET scan of the heart Open pop-up dialog box Close. PET scan of the heart This PET image shows an area of reduced blood flow from one of the arteries that feeds the heart.
Request an Appointment at Mayo Clinic. Share on: Facebook Twitter. Radiological Society of North America. Accessed April 6, What is PET?
Society of Nuclear Medicine and Molecular Imaging. Umterrainer M, et al. Recent advances of PET imaging in clinical radiation oncology. Radiation Oncology. Adam A, et al. Adrenal imaging. In: Grainger and Allison's Diagnostic Radiology. Elsevier; American College of Radiology. Cervical cancer. Accessed April 8, Morrow ES. Allscripts EPSi. Mayo Clinic. April 6, Collins DA expert opinion.
Used mostly in patients with brain or heart conditions and cancer, PET helps to visualize the biochemical changes taking place in the body, such as the metabolism the process by which cells change food into energy after food is digested and absorbed into the blood of the heart muscle. PET differs from other nuclear medicine examinations in that PET detects metabolism within body tissues, whereas other types of nuclear medicine examinations detect the amount of a radioactive substance collected in body tissue in a certain location to examine the tissue's function.
Since PET is a type of nuclear medicine procedure, this means that a tiny amount of a radioactive substance, called a radiopharmaceutical radionuclide or radioactive tracer , is used during the procedure to assist in the examination of the tissue under study.
Specifically, PET studies evaluate the metabolism of a particular organ or tissue, so that information about the physiology functionality and anatomy structure of the organ or tissue is evaluated, as well as its biochemical properties.
Thus, PET may detect biochemical changes in an organ or tissue that can identify the onset of a disease process before anatomical changes related to the disease can be seen with other imaging processes such as computed tomography CT or magnetic resonance imaging MRI. PET is most often used by oncologists doctors specializing in cancer treatment , neurologists and neurosurgeons doctors specializing in treatment and surgery of the brain and nervous system , and cardiologists doctors specializing in the treatment of the heart.
However, as advances in PET technologies continue, this procedure is beginning to be used more widely in other areas. PET may also be used in conjunction with other diagnostic tests, such as computed tomography CT or magnetic resonance imaging MRI to provide more definitive information about malignant cancerous tumors and other lesions.
Originally, PET procedures were performed in dedicated PET centers, because the equipment to make the radiopharmaceuticals, including a cyclotron and a radiochemistry lab, had to be available, in addition to the PET scanner. Now, the radiopharmaceuticals are produced in many areas and are sent to PET centers, so that only the scanner is required to perform a PET scan. Further increasing the availability of PET imaging is a technology called gamma camera systems devices used to scan patients who have been injected with small amounts of radionuclides and currently in use with other nuclear medicine procedures.
These systems have been adapted for use in PET scan procedures. The gamma camera system can complete a scan more quickly, and at less cost, than a traditional PET scan. PET works by using a scanning device a machine with a large hole at its center to detect photons subatomic particles emitted by a radionuclide in the organ or tissue being examined. The radionuclides used in PET scans are made by attaching a radioactive atom to chemical substances that are used naturally by the particular organ or tissue during its metabolic process.
For example, in PET scans of the brain, a radioactive atom is applied to glucose blood sugar to create a radionuclide called fluorodeoxyglucose FDG , because the brain uses glucose for its metabolism. Other substances may be used for PET scanning, depending on the purpose of the scan.
If blood flow and perfusion of an organ or tissue is of interest, the radionuclide may be a type of radioactive oxygen, carbon, nitrogen, or gallium. The radionuclide is administered into a vein through an intravenous IV line. Next, the PET scanner slowly moves over the part of the body being examined. Positrons are emitted by the breakdown of the radionuclide.
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