A breast scan is an imaging test to look at your breasts. It may also be called a scintimammography or nuclear medicine breast imaging. It's used when a mammogram hasn't given your doctor enough information. It's not considered a primary test for screening and doesn't replace the need for a mammogram.

A breast scan is a type of nuclear imaging test. This means that a tiny amount of radioactive matter is used during the scan. The radioactive matter, called tracer, sends out gamma rays. These are picked up by the scanner to make a picture of your breasts.

The areas of the breast where the radioactive tracer collects in greater amounts are called hot spots. The areas that don't absorb the tracer and appear less bright on the scan image are referred to as cold spots. Cancer cells are usually found by hot spots in a breast scan.

A breast scan can be helpful in diagnosing breast cancer in younger adults. Younger adults usually have denser breasts than older adults. Denser breast tissue can also happen because of:

• Fibrocystic disease
• Past breast surgery
• Radiation therapy
• Chemotherapy
• Biopsy
• Breast implants

You may need a breast scan if the results of a mammogram or other imaging exams, such as ultrasound or MRI, are not definite. Or your doctor may use a breast scan along with mammography or as a follow-up to breast exams or ultrasounds.

Your doctor may order a breast scan to:

• Look for a tumor.
• See how well blood is flowing through your breast tissue.
• Follow up after surgery, chemotherapy, or other breast cancer treatment.

Your doctor may have other reasons to recommend a breast scan. Talk with your doctor about the reason for your scan.

The risk from the radioactive tracer is very low. The amount used in the test is very small. You may feel some slight discomfort when the tracer is injected. Allergic reactions to the tracer are rare, but they may happen.

Lying on the scanning table during the procedure may cause some discomfort or pain for certain people.

Tell your doctor if you are:

• Allergic to or sensitive to medicines, contrast dyes, or latex.
• Pregnant or think that you might be pregnant. The scan may not be safe for the fetus.
• Breastfeeding. The tracer may contaminate your breastmilk.
• Are about to start your period. A scan done at this point may not be accurate.
• Have any other health conditions.

You may have other risks. Discuss any concerns with your doctor before the procedure.

• Your doctor will explain the procedure to you. Ask your doctor any questions that you may have.
• Make a list of questions you have about the procedure. Discuss these questions and any concerns with your doctor before the procedure. Consider bringing a family member or trusted friend to the medical appointment to help you remember your questions and concerns.
• You may be asked to sign a consent form that gives permission to do the procedure. Read the form carefully and ask questions if anything isn't clear.
• You don't need to stop eating or drinking before the test. You also won't need medicine to help you relax (sedation).
• Tell your doctor:
  • If you're allergic to or sensitive to latex, medicines, contrast dyes, or iodine.
  • If you're pregnant or think you may be pregnant.
  • About all the prescriptions and over-the-counter medicines and supplements you're taking.
• Tell the technologist if you have breast implants.
• Follow any other instructions your doctor gives you on how to get ready.

You may have a breast scan as an outpatient or as part of your stay in a hospital. The way the test is done may vary depending on your condition and your doctor's practices.

Generally, a breast scan follows this process:

1. You'll be asked to remove all jewelry and clothing above the waist. You'll be given a gown to wear.
2. An I.V. (intravenous) line will be started in your arm or hand opposite the breast to be looked at. If both breasts are being looked at, the I.V. line may be started in a vein in your foot.
3. The tracer will be injected into the I.V. line. You may have a slight metallic taste after the injection. This should last only a few moments.
4. You may be placed in different positions, depending on the type of machine being used. You may lie face down on a special table made for breast scans. The breast to be scanned will be placed through an opening in the table. Or you may have one of your breasts placed next to the camera of the scanner and compressed with a flat plate, just as with a mammogram. One breast is scanned and then the other breast is scanned. Some machines have cameras on each side of the breast.
5. The technologist will start taking images a few minutes after the injection. They'll place the scanner over the breast. Or the technologist may use a different kind of scan called SPECT.
6. You may be asked to change positions during the scan. For example, you may lie on your back or sit up. You may be asked to sit with your arms straight out or above your head.
7. When the scan is done, the I.V. line will be removed.

The breast scan is not painful. But you may have some discomfort or pain from lying still during the test. This may be because of recent surgery or a joint injury. The technologist will use all possible comfort measures and do the scan 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.

You may be told to drink plenty of fluids and empty your bladder often for 1 to 2 days after the scan. This will help flush the radioactive tracer from your body.

The medical staff will check the I.V. site for any signs of redness or swelling. Tell your doctor if you see any pain, redness, or swelling at the I.V. site after you go home. These may be signs of infection or another type of reaction.

You may go back to your usual diet and activities as directed by your doctor.

Your doctor may give you other instructions, depending on your situation.

Before you agree to the test or procedure, make sure you know:

• The name of the test or procedure
• The reason you are having the test or procedure
• What results to expect and what they mean
• The risks and benefits of the test or procedure
• What the possible side effects or complications are
• When and where you are to have the test or procedure
• Who will do the test or procedure and what that person's qualifications are
• What would happen if you did not have the test or procedure
• Any alternative tests or procedures to think about
• When and how you will get the results
• Who to call after the test or procedure if you have questions or problems
• How much you will have to pay for the test or procedure