What is Nuclear Medicine?
Nuclear medicine uses a small quantity of radioactive material combined with pharmaceuticals to look at the function of the body part rather than the anatomy, as with traditional x-ray. The nuclear medicine gets injected into the body part being scanned and is measured as it moves through that body part.
There are many different nuclear medicines available to study different organs of the body, depending on the part of the body and condition to be diagnosed or treated. Nuclear medicines are mainly introduced into the patient's body by injection but can also be introduced by swallowing or inhaling. Nuclear medicines are designed to go to a specific place in the body where there could be disease or an abnormality.
One of the more common tests performed is a nuclear stress test but a complete list of procedures can be viewed below.
What to Expect During Your Nuclear Medicine Exam
Your exam will be completed by a technologist who is board certified and has been specifically trained and educated in nuclear medicine technology. The technologist's responsibilities include the administration of the nuclear medicine and operation of the special imaging equipment. During this imaging procedure, you will lie down and a gamma camera will be placed close to your body. This procedure can take anywhere from fifteen minutes to a couple of hours to complete. The images allow the radiologist to interpret the nuclear medicine study. Depending on the kind of images that need to be taken, the gamma cameras will be stationary or rotate around the body. Gamma cameras do not hurt and are very quiet in their operation. Nuclear medicine gamma cameras also do not emit radiation.
Nuclear Stress Test
In certain tests, like those being performed on the heart, a physician will want to see how the part of the body looks in action and not just a still image. In those cases a nuclear stress test is performed to see the heart at a normal resting rate as well as a more vigorous rate. In these nuclear stress tests nuclear medicine is injected and you will be asked to walk on a treadmill. In certain cases where walking on a treadmill is not possible for the patient, a chemical stress test can be administered where another medicine can be injected to increase the heart rate.
Preparing for Your Exam
Please check the list of common procedures below for any prep as they vary by part of the body being scanned. Please inform the nuclear medicine technologist if you may be pregnant. If there is any possibility of pregnancy, a pregnancy test may be ordered before the exam. All therapeutic treatments require a blood pregnancy test before the treatment. It takes at least 75 minutes to receive the results from the pregnancy test.
Thyroid uptake and scans are used to examine the overall function and visual appearance of the thyroid gland. Generally it is a two-day procedure with day one imaging consisting of one hour. The Iodine 123 capsule is taken orally.
Lung scans (V/Q) are used to show both blood flow and the movement of air in and out of the lungs to help detect the presence of blood clots. Imaging time is usually 45 minutes to one hour. The two-part test consists of first breathing through a mask so an image of airflow can be captured and then using an IV injection so an image of the lung's blood perfusion (blood delivery) can be captured. A chest X-ray is required along with this scan.
Liver/spleen scans are used to help diagnose disorders such as cirrhosis, hepatitis and cysts. Exam time is usually one hour following an IV injection.
Gastric emptying scans are used to help diagnose the specific emptying time of food being processed by the stomach. The exam takes at least 90 minutes with patients lying on their backs after they have finished a meal of oatmeal or eggs containing a small amount of a nuclear medicine.
Hepatobiliary/gallbladder (HIDA) scans are used to identify potential obstructions in the gallbladder and specific ducts leading to the small intestine from the liver. HIDA scans can also determine if a gallbladder is diseased or not functioning properly, with an additional medication. This medication can cause the gallbladder to contract (which may temporarily reproduce suspected gallbladder symptoms) and allows the technologist to measure the function of the gallbladder. Morphine is sometimes administered during a HIDA scan to help visualize the gallbladder, not for pain relief. Please bring a driver, in case of morphine administration, or have someone pick you up if you drive yourself. Your ordering physician will give you further specific instructions before your study. Exam time is usually one to two hours, and all nuclear medicine is administered by IV.
Bone scans are used to detect bone growth, metastatic tumors, fractures, infections and other conditions. All bone scans require an IV injection, and delayed imaging will occur from three to four hours after injection. Scan times range from 30 minutes to one hour. Specific bone scans include:
- Total body bone scan - Whole body images are taken from the top of the head to the feet. Routine additional images may also be acquired.
- Three phase bone scan - When infection is suspected images are taken of the affected area, upon IV injection of the nuclear medicine, along with delay images.
- Limited bone scan - When a specific area of the body is of concern, a limited bone scan to that area is obtained. Imaging usually begins three to four hours after injection.
- Bone SPECT - A limited bone scan is performed prior to SPECT imaging. The SPECT acquisition allows a more detailed and focused set of images to a specific area of interest, especially if micro fractures or other abnormalities are suspected.
Renal scans are used to detect disease, damage and malformations of the kidneys and urinary tract. Nuclear medicine renal scans may also detect if there are structures in the vessels leading to the kidneys (renal arterial stenosis) and blockages from kidney stones in the renal pelvis (UPJ obstructions.) Exam times are 30 minutes or one hour, depending on the diagnoses. Medications may be ordered along with the nuclear medicine renal scans, and your physician will give you the specific instructions for those exams. This exam requires an IV.
Iodine 131 therapy is used to treat specific thyroid-related disorders such as hyperthyroidism (Grave's Disease) or thyroid cancer. Our nuclear medicine department covers all aspects of I-131 therapy including the mechanism of treatment, side effects and radiation safety.
Brain scans are used to detect dementia and other cerebral vascular disorders by giving the physician a view of the general perfusion (blood delivery) to the brain. These exams generally take two hours, and all nuclear medicine are administered by IV.
What to Expect After Your Nuclear Medicine Exam
The images are reviewed and interpreted by a radiologist and a written report will be sent to the physician who ordered the exam. Your doctor will discuss the results of your scan with you at your next appointment.