(Breast Scintigraphy, Scintimammography, Radionuclide Breast Imaging, Molecular Breast Imaging)
What is a breast scan?
A breast scan is a specialized radiology procedure used to assess the breasts when other examinations have been inconclusive.
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A breast scan is a type of nuclear radiology procedure. This means that a tiny amount of a radioactive substance is used during the procedure to assist in the examination of the breasts. The radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is absorbed by certain types of body tissues.
The radionuclide used in breast scans is usually a form of technetium. Once absorbed into the breast tissue, the radionuclide emits a type of radiation, called gamma radiation. The gamma radiation is detected by a scanner, which processes the information into a picture of the breasts.
By measuring the behavior of the radionuclide in the body during a nuclear scan, the physician can assess and diagnose various conditions, such as tumors, abscesses, hematomas, organ enlargement, or cysts. A nuclear scan may also be used to assess organ function and blood circulation. Cancer cells take up more of the radionuclide than normal cells, and the cancer cells can be detected with a specialized camera.
A breast scan is used to identify breast cancer, especially in younger women, who usually have denser breasts than those of older women and for whom mammography may not be accurate. Other reasons for dense breast tissue can include fibrocystic disease, fatty tissue, previous breast surgery, radiation therapy, chemotherapy, biopsy, or breast implants.
Other related procedures that may be used to evaluate breast problems include mammography, breast ultrasound, and breast biopsy. Please see these procedures for more information.
Anatomy of the Breasts
Each breast has 15 to 20 sections, called lobes, which are arranged like the petals of a daisy. Each lobe has many smaller lobules, which end in dozens of tiny bulbs that can produce milk.
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The lobes, lobules, and bulbs are all linked by thin tubes called ducts. These ducts lead to the nipple in the center of a dark area of skin called the areola. Fat fills the spaces between lobules and ducts.
There are no muscles in the breast, but muscles lie under each breast and cover the ribs.
Each breast also contains blood vessels and vessels that carry lymph. The lymph vessels lead to small bean-shaped organs called lymph nodes, clusters of which are found under the arm, above the collarbone, and in the chest, as well as in many other parts of the body.
A mammography is generally used for routine screening, but a breast scan may be used when the results of mammography are uncertain or as an adjunct to mammography.
Other indications for a breast scan include follow-up after surgery, chemotherapy, or other breast cancer treatment. Staging of breast cancer may be determined with a breast scan. Another type of nuclear scan, called lymphoscintigraphy, may be used to determine whether the cancer has spread to the lymph nodes of the armpit.
There may be other reasons for your physician to recommend a breast scan.
The amount of the radionuclide injected into your vein for the procedure is small enough that there is no need for precautions against radioactive exposure. The injection of the radionuclide may cause some slight discomfort. Allergic reactions to the radionuclide are rare, but may occur.
For some patients, having to lie still on the scanning table for the length of the procedure may cause some discomfort or pain.
Patients who are allergic to or sensitive to medications, contrast dyes, shellfish, or latex should notify their physician.
If you are pregnant or suspect that you may be pregnant, you should notify your physician due to the risk of injury to the fetus from a breast scan. If you are lactating, or breastfeeding, you should notify your physician due to the risk of contaminating breast milk with the radionuclide.
Imaging immediately before your menstrual period is contraindicated, as the results may be inaccurate.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your physician prior to the procedure.
- Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
- You may be asked to sign a consent form that gives permission to do the procedure. Read the form carefully and ask questions if something is not clear.
- No fasting or sedation is required before the procedure.
- Notify the radiologist or technologist if you are allergic to or sensitive to medications, contrast dyes, or iodine.
- If you are pregnant or suspect that you may be pregnant, you should notify your physician.
- Notify your physician of all medications (prescribed and over-the-counter) and herbal supplements that you are taking.
- Notify the radiologist or technologist if you have breast implants.
- Based upon your medical condition, your physician may request other specific preparation.
A breast scan may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your physician's practices.
Generally, a breast scan follows this process:
- You will be asked to remove all jewelry and clothing above the waist, and you will be given a gown to wear.
- An intravenous (IV) line will be inserted in your arm or hand opposite the side of the breast to be examined. If both breasts are being evaluated, the IV may be inserted into a vein in the foot.
- You will be positioned lying face down on a table designed to provide access to the breasts. The breast to be imaged will be placed through an opening in the table.
- The radionuclide will be injected into the IV. You may experience a slight metallic taste after the injection.
- Imaging will begin a few minutes after the injection. A specialized type of camera, called a scanner, will be placed over the breast and will record the radiation emitted. Alternatively, an imaging method called SPECT (single-photon emission computed tomography) may be used to create an image of the breast for evaluation.
- You may be asked to assume different positions during the scan, such as lying flat on your back or sitting upright. You may be asked to sit with your arms straight out or above your head in order to expose the armpits.
- When the scan is completed, the IV will be removed.
While the breast scan itself causes no pain, having to remain still for the length of the procedure might cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure such as surgery. The technologist will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.
You should move slowly when getting up from the scanner table to avoid any dizziness or lightheadedness from lying flat for the length of the procedure.
You may be instructed to drink plenty of fluids and empty your bladder frequently for about 24 hours after the procedure to help flush the remaining radionuclide from your body.
The IV site will be checked for any signs of redness or swelling. If you notice any pain, redness, and/or swelling at the IV site after you return home following your procedure, you should notify your physician as this may indicate an infection or other type of reaction.
You may resume your usual diet and activities, unless your physician advises you differently.
Your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.