- What is a Nuclear Medicine Scan?
A Nuclear Medicine Scan is a procedure that uses small amounts of radioactive material to diagnose or treat a disease. The radioactive tracer is injected intravenously into the patient and a special device called a gamma camera detects the radiation emitted by the patient's body. The information is then used to form an image.
- What does it show?
It shows the function of the organ being studied. Many abnormalities can be detected in the early stages before it has had a chance to progress to a level that can be imaged by other areas.
- Does the procedure hurt?
The scan is not painful although the injection of the radioactive isotope may be uncomfortable.
- What is a radioisotope?
Radioisotope is radioactive material that is injected. It consists of tiny particles with a tracer that is specific to the body part being studied. The radioactive dose received by the patient is very small and comparable to many X-ray procedures. The tracer material is eliminated from the body in a day or two.
- What can I expect?
The nuclear medicine technologist will position you on the imaging table. The radioisotope will then be injected or taken orally. Most scans require several images and you may be asked to move into different positions during the scan. The machine will come very close to you but it is very important not to move. The machine resembles a large donut with the scanning table in the middle.
- Why are some scans longer than others?
Depending on the organ that is studied, the tracer is absorbed more slowly into some body parts. Some exams require a wait between the time of the injection and the time of the scan.
- Where do you give the injection, and will I have any side effects?
The injection is given into a vein in the arm, much like having your blood drawn. You will not feel the injection of the isotope. Side effects are very rare.
How do I prepare for my exam?
Exam preps are as follows.
- MUGA (ventriculography, gated blood pool scans): no preparation, exam takes about one hour.
- Bone scan: Normal diet, but drink 32-48 ounces of water between injection time and scan time. Exam length is approximately 30 minutes.
- Spect: No preparation, exam length 20 minutes.
- Thyroid: Nothing to eat or drink four hours prior to exam. X-ray procedures containing iodine are prohibited for eight weeks and thyroid medications aren’t allowed for six weeks. It takes two days to complete this scan. Day 1 - 15 minutes in the morning, one hour in the afternoon. Day 2 - 15 minutes in the morning. Patient may eat at noon and after on the first day.
- Lung: No preparation, exam length 30-45 minutes.
- Liver/sleen: No preparation, exam length 30 minutes.
- Liver hemangioma: No preparation, scan is completed about four hours after the time of injection. Exam time is one hour.
- Gallium: May have to take laxatives the night before exam to clean the colon. (Technologist will instruct). This exam takes 1-4 days to complete. Day 1 - Injection of isotope. Day 2 - scan length one hour. Day 3 - scan length one hour. Day 4 - not likely to happen, but could be one hour.
- White blood cell localization: no preparation. You should plan to spend most of the day in the department. Blood will be drawn early that morning and you will be ready for another injection and scan about six hours later. The scan will take about two hours.
- Captopril renal scan: Patient needs to be well hydrated. Do not take any blood pressure medications the night before the exam, no diuretics (Lasix) the morning of the exam. No ACE inhibitors for 24 hours prior to the exam. List of ACE inhibitors: Lotensin, Capoten, Vasotec, Monopril, Prinivil, Univasc, Accupril, Altace. Scan time is two hours for Captopril scan. Scan time is one hour for baseline renal scan.
- Venogram: No preparation. Exam length approximately two hours.
- DMSA renal scan: No preparation. Two hour wait for injection. Scan length is one hour.
- Bile Duct: Nothing to eat or drink 6-8 hours before scan. No gum chewing or smoking. Exam length is approximately 1-2 hours.
- Iodine Therapy 131: Nothing to eat or drink four hours prior to the exam. Exam time is 15 minutes.
- Thallium or Sestamibi (Mibi) Scan: Nothing to eat or drink four hours prior to scan. See section under Cardiac Studies. Preparation for this exam can be extensive. Some medications may need to be withheld before the exam. Plan to spend most of the day for your test. The test is administered in two parts. Part one takes about 1.5 hours, and Part 2 will be about 3-4 hours later and will take approximately 30 minutes.
- GI bleeding scan: No preparation.
What can I expect from my exam?
A complete list of exam descriptions follows.
- MUGA (Ventriculography, gated blood pool) - Used to measure the heart's function by determining the ejection fraction. This is the percentage of blood that is ejected from the heart with each beat. Blood will be drawn from the patient and a small amount of radioactive material will be mixed with it. It will then be reinjected into the bloodstream. You will have EKG patches put on your chest and small wires will be connected that measure your heartbeats. You will be placed on the imaging table for about one hour while the area is scanned.
- Bone scan - Used to determine bone cancer, fractures, sport injuries, arthritis, and osteomyelitis (bone infection). You will be given an injection of a small amount of radioactive isotope. The scan will follow three hours later. You will need to lie very still on the imaging table for about 20 minutes while pictures are taken.
- Spect scan - This test is usually done in combination with another scan to obtain cross sectional images that are similar to a CAT scan. It does not require any additional injections, but may add another 20 minutes to your scan time.
- Thyroid Scan and Uptake - This test measures thyroid function. It also may be used to diagnose causes of thyroid swelling or trouble swallowing. You will be given a radioactive iodine pill in the morning. You will return about six hours later for a scan and uptake measurement. This takes a little more than one hour. You will return the next morning for the uptake only. The uptake measures how well your thyroid is working. This is accomplished by placing a metal probe close to your neck, which detects the radioactivity. This second part of the exam only takes about 15 minutes.
- Lung scan - Used to determine if there are blood clots (pulmonary emboli) in the lungs. The lung scan consists of two parts Part 1 - Ventilation - requires you to breathe radioactive gas through a tube for about 10 minutes. It reveals how air is moving through the lungs. You will be scanned afterward for about 15 minutes. Part 2 - perfusion - requires an injection. It determines if blood is flowing normally through the lungs. Scanning takes an additional 15 minutes.
- Liver/Spleen scan - Used to detect masses, abscesses, or cirrhosis of the liver. It measures liver and spleen size. You will receive an injection and 30 minutes later the scan will begin. You will lie very still on the scanning table. It takes about 30 minutes to perform the scan.
- Liver hemangioma scan - Used to determine if a liver tumor is benign (noncancerous). You will have blood drawn, which is added to a small amount of radioactive material. It is reinjected back into the bloodstream and a scan is performed immediately after the injection and again about 3-4 hours after injection. Total scan time is about one hour.
- Gallium scan - Used to detect tumors, infection or inflammation. This scan will take 3-4 hours to complete. Day 1 consists of an injection only. Day 2, 3 and 4 consists of a scan that lasts about one hour each. You will lie still on the image table each time.
- White blood cell localization - This scan is done to look for infection. White blood cells fight infection and this scan detects where large amounts of white blood cells are located within your body. You will have your blood drawn and it will be mixed with a small amount of radioactive material. It will be reinjected 4-6 hours later. A scan will follow 30 minutes and 2 hours after reinjection. Each scan takes about 30 minutes.
- Renal scan (Captopril or Baseline) - Used to diagnose kidney blockage or urine flow, abnormal kidney function, and causes of high blood pressure. If you are having a Captopril Renal scan you will be given a Capoten pill one hour before the procedure. Your blood pressure will be constantly monitored since this is a highly effective blood pressure medication. This type of scan is conducted to determine the cause of high blood pressure. You will then be given an injection of a radioactive material and scanned for 30 minutes. If you are having a baseline renal scan then you will be given an injection and scanned for 30 minutes. No Capoten pill will be given. Please be sure to follow proper preparation prior to the scan.
- DMSA renal scan - Used to diagnose causes of kidney infection. It is usually only performed on children. The radioactive material will be administered and the scan follows. The child may need a mild sedative during the procedure. Parents or family members can stay with the child during the procedure.
- Venogram - used to determine if a blood clot in the leg is new (acute) or old (chronic). A new clot needs instant attention and must be diagnosed properly. This scan will be performed with the patient on the scanning table. An injection will be given and pictures will be made of the legs. The patient must hold still during the procedure. The scan is done in two parts: one part takes approximately 10 minutes following the injection. One at 90 minutes after the injection.
- Bile Duct scan - This scan is performed to determine if the gallbladder and the associated bile ducts are working correctly. A normal (non-diseased) gallbladder should contract when prompted and empty the bile into the bowel. This helps to digest foods. The patient will receive an IV for this procedure because several injections will be given. After injection, pictures will be taken every 15 minutes for one hour. This injection allows physicians to clearly see the gallbladder. When it becomes full, another injection (Kinevac) will be administered. This causes the gallbladder to contract. Kinevac can sometimes cause abdominal pain and cramping, but it will be injected very slowly to avoid these side effects. If a gallbladder is sick, then it will not contract normally, but this function will be measured after the exam is completed. Not all bile duct scans require the use of Kinevac, but the scan time will still last between one and two hours. Occasionally some patients have to return several hours later for a follow up scan.
- I 131 Therapy - This radioactive pill is given to reduce the function of the thyroid gland in cases of over activity permanently. There is no scan involved for this test and you may leave soon after the pill is given.
- GI bleed - This test determines the cause of gastrointestinal bleeding. It requires an injection of radioactive material and the scan follows immediately. Several pictures will be taken during a one to two hour period and the patient may have to return several hours later for a follow up scan.
- Thallium or Sestamibi (Mibi) scan - This test is conducted to determine if there is chronic damage to the heart or if there is a blockage in a coronary artery resulting in decreased blood flow to the heart. This is called ischemia. This scan is performed in two parts: Part 1 - If you are able to walk on a treadmill - an IV will be started and an EKG (monitor of heart rhythm with patches that are stuck on your chest with wires connected to them) will be performed. You will be asked to start walking on the treadmill with a cardiologist (heart doctor) present. The radioactive material will be injected and you will be scanned soon afterwards. This images your heart in the stress or working phase. Part 1 if you are unable to walk on a treadmill -you will be given a medication as an alternative to walking. It will speed up your heart and make it work. You will have an IV and an EKG. Images will be recorded. You will return 3-4 hours later for an additional scan. Another injection will be given at that time. You will be asked to lie on the imaging table for about 20 minutes each time for the scan. You also will need to keep your arms above your head. The technologist will make you as comfortable as possible. For more cardiac information, please see the section on cardiac studies.
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