Nuclear medicine involves the use of low levels of radioactive materials (or tracers) to help diagnose and treat a variety of diseases including many types of cancer, heart disease, kidney and thyroid function, brain abnormalities and other issues.
Unlike others tests that examine the anatomy, nuclear medicine exams determine the cause of the medical problem based on the function or physiological processes of the organ, tissue or bone. The tracers accumulate most where there is a high level of chemical activity, forming hot spots, and giving information that often cannot be obtained in any other way, often saving the patient the necessity of exploratory surgery.
In a nuclear medicine test, the radioactive material is introduced into the body by injection or swallowing, and goes to the site being evaluated where it can detected by the scanner. The materials may take several hours or even days to reach the place where it needs to go, depending on the exam. The actual scanning time can be as little as 20 minutes or several hours and, depending on the exam, may take place over several days. In some cases, nuclear medicine images can be superimposed on images from other technology (such as PET and CT scans) to allow the two images to be “fused” and interpreted on one image for a more complete picture and more accurate diagnosis.
You might feel a slight cold sensation moving up your arm if you are injected with the tracer materials, but it does not lat long. If swallowed, it has almost no taste.
As with all testing that involves radiation, generally, nuclear medicine tests are not recommended for pregnant women, as unborn babies have a greater sensitivity to radiation than children or adults. If you are pregnant, think that you may be pregnant or are breastfeeding, your doctor may order a different type of diagnostic test. If you are planning to become pregnant, ask your doctor how long you should wait after the treatment.
Be sure to leave all jewelry at home.
The radiotracer will be flushed out of your system over time, and you should drink plenty of water to help speed this process. You may be given other instructions by the technologist.
Below are nuclear medicine studies in which specific preparation information is provided:
A brain scan may be necessary to investigate problems within the brain itself or in blood circulation to and from the brain (perfusion imaging). Generally, no special preparation is needed. However, if special preparation is required, your doctor will let you know.
Our nuclear medicine technologist will instruct you on the special preparations for this exam at the first visit.
After you arrive in the nuclear medicine department, an IV tube is placed into a vein in your arm. A special “tracer” drug that shows up on scans of the gallbladder is injected through the IV. Images of your abdomen are taken over a period of 45 to 60 minutes. A HIDA scan requires an average of about 2 hours to complete. It may take longer if your gallbladder is not functioning properly.
You will need to begin fasting at midnight the night prior to your exam. This exam should not follow any prior barium studies on the same day.
A tracer is injected in your arm. 10- 15 minutes after the injection you will lie on your back and images from different positions will be taken of your liver and spleen. Generally, no special preparation is needed. However, if special preparation is required, your doctor will let you know.
Meckel’s diverticulum is an abnormality in the small intestine that is present at birth. A Meckel’s diverticulum scan is a nuclear medicine test that detects the abnormally-located gastric mucosa. Gastric mucosa is the mucous membrane layer of the stomach.
Images are taken for a period of 45 minutes, immediately following an injection containing a radioactive substance. The radioactive material will safely leave your body through the urine.
You will need to begin fasting at midnight the night prior to your exam. This exam should not follow any other barium studies for three days prior to this exam.
Renal Scan with Captopril
You will need to begin fasting 4 hours prior to your exam, except for water. It is important to be hydrated for this exam; drink 8 – 12 oz. fluid prior to the test.
It is preferred to discontinue any ACE inhibitor medications 48 hours prior to the examination. (Consult your physician first.)
Thyroid Metastases Study (Whole Body 1-131 Study)
You should not have an exam that required contrast for 30 days prior to this exam.
The exam begins with approximately 20 minutes for the injection of the tracer materials, but pictures are not taken until about 48 hours later. The imaging itself lasts about ninety minutes.
You must not be taking the following thyroid hormones:
- Propylthiouracil (PTU) and Tapazole for at least 1 week.
- Synthroid for 3-4 weeks.
Additionally, you must not be taking the following medications:
- Adrenocorticisteroids, Perchlorate, Amiodarone, Bromides Salicylcastes (lrg doeses) for 3 weeks.
You must not have had tests that use iodinated contrast material (IVP, CT with contrast, myelogram, angiogram) for at least 3 weeks.
This exam should not follow any barium studies for three days prior to the exam.
It is important to be hydrated for this exam; drink 24 oz. of fluid prior to test. However, it is not necessary to have a full bladder for the exam.