Understanding Nuclear Medicine
Nuclear medicine describes the branch of medical imaging that uses small doses of radioactive material to diagnose and treat disease. Nuclear medicine uses intravenous injections of radioisotopes or tracers. Each of these tagged molecules emits a tiny amount of radiation, which is detected over time to create a series of images.
Diagnostic nuclear medicine can assess both organ structure and function allowing for earlier detection and diagnosis of diseases. For each type of test, a specific chemical compound is tagged with a radiotracer, giving each type of exam sensitivity and specificity for particular diseases.
Such scans are useful in:
- Analyzing kidney function
- Visualizing heart blood flow and function
- Scanning lungs for respiratory and blood flow problems
- Identifying blockage, malfunction, or inflammation of the gallbladder
- Evaluating bones for fractures, infection, abnormal growth or arthritis
- Detecting, diagnosing and following certain types of cancer
- Investigating abnormalities in the brain
- Therapeutic procedures, such as thyroid therapy to treat cancer affecting the thyroid gland.
During a nuclear medicine procedure, radiologists target these radioisotopes toward specific organs, bones or tissues to gather crucial information about a particular type of cancer, disease or other abnormalities within the body. Depending on the type of nuclear medicine exam, the radioisotope may be injected into a vein, swallowed or inhaled as a gas. As it accumulates in the area of the body being examined, it gives off gamma rays. The radiologist employs a gamma camera, a positron emission tomography (PET) scanner or probe to measure the radiation and produce detail pictures of both the structure and function of your organs and tissues.
Images procured through nuclear imaging can be combined with those from computed tomography (CT) or magnetic resonance imaging (MRI) to superimpose functional information and anatomy. This branch of imaging also includes single photon emission computed tomography/computed tomography (SPECT-CT) and positron emission tomography/computed tomography (PET-CT) scanners that are able to perform multiple imaging methods at the same time.
Because nuclear medicine involves exposure to radiation, concerns arise about the risks. WellStar technologists and radiologists always use the smallest possible dose of radiation necessary. Experts including radiologists and other WellStar physicians believe that the information gathered through nuclear medicine tests outweigh the minimal risks of radiation exposure.
WellStar Resources and Support
WellStar uses state-of-the-art equipment and innovative digital systems integrated into all of its nuclear medicine technologies to ensure quality images at minimum dose levels.
Nuclear medicine is available at all WellStar hospitals as well as at WellStar Kennestone Imaging Center at 700 Building and WellStar Kennestone Imaging Center at 340 Building. PET/CT and SPECT are available at the WellStar Kennestone Imaging Center at 340 Building.
Nuclear Medicine Procedures
A number of imaging examinations fall under the category of nuclear medicine, and each has its own specific preparations, procedures and post-examination requirements. For each examination, you will be asked to provide your medical history and review it with a technologist. You may be required to remove clothing and any jewelry or other objects from the area of your body to be examined.
You should also inform your WellStar physician or radiologist if you believe you might be pregnant or if you are breastfeeding.
For many nuclear medicine exams, there is a wait for up to three or four hours between the time of injection or ingestion of the radioactive tracer and the time of your actual examination. You may be allowed to leave and resume your normal activities during this time.
As the test is performed, the scan camera will be positioned very close to your body, but it will not touch you. During the exam, you will need to be as still as possible since movement can blur images. You will be able to talk to the technologist during the test in case you need help or feel uncomfortable.
Bone scans require no special preparations, but you should drink plenty of water the day before your test. After the injection, you will have to wait four to six hours before your test begins for a single-phase exam. A three-phase exam includes an initial episode of imaging followed by delayed imaging. After your test, you may resume normal activities.
For these scans designed to search for tumors and abnormal growths in your body, you will need to take a mild laxative the night before your test and through the duration of the test. Due to the tracking of the radioactive tracer through your body, the exam may involve several imaging sessions over the course of four days. Because several medications can affect this test, you may be asked to refrain from taking them during the test.
Gallbladder/Gastric Emptying/Cardiac Stress Test
For this test, do not eat or drink anything six hours prior to your test. This includes taking medications. These exams typically take two to four hours. After the test, you may resume normal activities.
For this test, do not eat or drink anything six hours prior to your test. This includes taking medications. If you have had an iodinated contrast (X-ray or CT dye) or certain types of iodine containing oral contrast within the past six weeks, you will not be able to have this test due to trace amounts of iodine left behind. You should consult with your WellStar physician if you are on any thyroid medication as it is recommended that you not take it for at least four weeks before taking this type of exam.
A cisternogram studies the flow of cerebral spinal fluid within the brain and spinal canal and requires a lumbar puncture (spinal tap) for the radioactive tracer to be injected. After the injection, you will have to wait four to six hours before the test begins, and you may have to remain at the hospital for the duration. After your first series of scans, you may leave and resume normal activity. You will return several times over the next three days to complete the rest of the images.
H. Pylori Test
This test examines the body for the helicobacter pylori (h. pylori) virus, the bacteria most responsible for ulcers in your body. For this exam, do not eat or drink anything six hours prior to your test. You must not have had any antibiotics or over-the-counter medication containing bismuth (Mylanta®, Pepto Bismol® or Maalox®) within four weeks of taking the exam. If you have had an oral contrast (barium) within the past eight hours, you will not be able to take this test.
For this test, do not eat or drink anything six hours prior to your test. This includes taking medications. If you have had an iodinated contrast (X-ray or CT dye) or an oral contrast (barium) within the past six weeks, you will not be able to have this test due to trace amounts of iodine left behind. You should consult with your WellStar physician if you are on any thyroid medication as it is recommended that you not take it for at least four weeks before taking this type of exam.
Other restrictions and guidelines will be provided in advance of the exam.
To avoid the risk of contamination of radioactive materials after thyroid therapy, you should follow these steps for at least two days:
- Wash your hands thoroughly with soap and water after each toilet use.
- Flush the toilet two or three times after each use.
- Rinse the sink and bathtub thoroughly after each use.
- Drink plenty of fluids
- Use separate or disposable eating utensils and wash separately.
- Use separate towels and washcloths and launder separately.
- Avoid prolonged physical contact with others and minimize time spent with pregnant women and children.