Nuclear Medicine is a subspecialty within the field of radiology. It includes diagnostic imaging studies that demonstrate body anatomy and function. The images are based on the distribution of a radioactive substance given to the patient, either intravenously, by mouth or inhaled into the lungs. Generally, radiation to the patient is similar to that resulting from standard x-ray examinations. Nuclear medicine images can assist the physician in diagnosing diseases. Tumors, infections and other disorders can be diagnosed by evaluation organ function.
A radiopharmaceutical agent, or tracer, is usually administered into a vein. Depending on the type of exam that is being performed, the imaging will be done either immediately, a few hours later, or even several days after the injection.
Imaging time varies, generally ranging from 20-45 minutes. During this time, you will be asked to lie under a gamma camera that is placed close to your body. The camera does not emit radiation but simply records the radiation emitted from the tracer that was administered. While the images are being obtained, you must remain as still as possible and refrain from talking in an effort to avoid blurry images. Some procedures require multiple images taken over a period of time. The radioactive tracer decays over time and is eliminated through normal body functions.
An NHRA physician with expertise in nuclear medicine interprets these images and sends a report of findings to your doctor. Although nuclear medicine studies are used primarily for diagnosis, tracers also can be used to treat some disease, including hyperthyroidism and certain cancers.
Your physician will receive the results of the exam, discuss the findings with you and prescribe treatment as necessary.
A nuclear medicine bone scan is a diagnostic test used to evaluate abnormalities involving bones and joints and to detect infection, bone lesions, degenerative bone disorders or fractures.
A gallium scan is a nuclear medicine test that is conducted with a camera that detects gallium, which is a radionuclide—a radioactive chemical substance.
Gallium is known to accumulate in inflamed, infected or cancerous tissues. The scans are used to determine if a patient with an unexplained fever has an infection, and to identify the site of any infection. Gallium scans also may be used to evaluate cancer following chemotherapy or radiation therapy.
What To Expect
Gallium scans usually require two visits to the nuclear medicine department.
During the first appointment, which will last about 15 minutes, you will be given an injection of gallium into a vein in your arm. The injection will cause no more discomfort than having blood drawn.
You will be scheduled to return for imaging 72 hours later. Imaging may involve several close-up views, whole body scanning or tomography.
During the imaging process, you must lie very still on an imaging table for about 30 to 60 minutes. A camera will be moved across your body to detect and capture images of concentrations of the gallium. Back (posterior) and front (anterior) views usually are taken, and sometimes a side (lateral) view is used.
The camera may occasionally touch your skin, but will not cause any discomfort.
The camera will detect signals from any areas in which the radionuclide has accumulated.
A gastric emptying scan (GES) is a nuclear medicine exam that enables doctors to identify stomach abnormalities. Radioactive material embedded in a meal emits gamma rays, which are detected by a gamma camera that produces electronic images of the stomach. This test offers the best means of detecting diseases that affect stomach contractions, an important function of the digestive process.
What To Expect
You will begin by drinking a liquid or eating a meal in which a nuclear medicine technologist has mixed a trace amount of radioactive material. You will not taste the radioactive tracer, nor will it have any affect on your bodily functions.
After you finish the meal, you will be asked to stand in front of a gamma camera for 1 minute. Additional images will be taken every hour up to 4 hours. You may bring a book or other materials with you to occupy your time in between images. When patients are children, their parents or guardians stay with them throughout the entire procedure.
A gallbladder nuclear medicine scan can assess gallbladder function. It is used to detect abnormalities of the gallbladder and to diagnose blockages of the duct that leads from the gallbladder to the small intestine or to assess inflammation (cholecystitis). Common reasons for having a gallbladder scan include pain in the right upper abdomen, loss of appetite, or nausea and vomiting.
What To Expect
You will be asked to lie on a table while a small amount of radiotracer is injected into a vein in the arm. After the radiotracer is injected, a special camera, called a detector, will be positioned close to your abdomen. The detector will take pictures continuously for 60 minutes as the tracer passes through your liver and into your gallbladder and small intestine. You will need to lie very still during this time to avoid blurring the pictures. If your physician needs additional information about how your gallbladder is functioning, you will be given a second intravenous injection of a medication to make your gallbladder contract. Images will be acquired for an additional 20-30 minutes.
The images will be interpreted by a radiologist who specializes in nuclear medicine imaging and a report will be sent to your doctor.
A renal imaging scan is a simple outpatient test that involves injecting small amounts of radioactive substances called “tracers” into the body, and then recording images of the kidneys and bladder using a special camera that is sensitive to the tracers. The images obtained can help in the diagnosis and treatment of certain kidney diseases.
Renal exams show various structures that make up the kidney, and also indicate how well the kidneys are functioning.
What To Expect
You will be asked to lie comfortably on an exam table. A nuclear medicine technologist will position the camera as close as possible to your kidney to obtain the best images.
The technologist will administer the radiopharmaceutical tracer material either with one injection or through an intravenous (IV) line. Imaging will begin immediately after the tracer is injected.
You must lie still during imaging to prevent blurring. Renal imaging exams take from 45 minutes to two hours to complete, but most typically require about 45 to 60 minutes. Once satisfactory images have been obtained, a nuclear medicine radiologist will interpret them and will send a report to your physician.
A thyroid scan is used to study the structure and function of the thyroid gland, including size, shape and location. A radioactive tracer material allows the nuclear medicine physician to examine the thyroid function.
What To Expect
This is a two-day procedure. On the first day, you will be asked questions regarding any prior tests, medication, symptoms or family history of thyroid problems. You will then be given one to three capsules containing radioactive iodine that will accumulate in your thyroid. The process takes 30 minutes. After consuming the pills, you may continue to eat and drink anything you please. Patients sometimes are asked to return in four to six hours and at 24 hours for thyroid assessment.
The scan will be performed on the second day, for which no special preparation is required. You will lie comfortably on a scanning table while images of your thyroid are produced during a 30-minutes session. After the exam, the technologist will process your images using a computer. A radiologist will evaluate the images and dictate a report, which will be sent to your physician. You will receive the results of the exam from your doctor.