Breast magnetic resonance (MR) imaging can help physicians screen high-risk patients, evaluate the extent of a known breast cancer, and further evaluate areas of concern found on mammograms and ultrasounds or during physical examinations.
The American Cancer Society recommends breast magnetic resonance imaging screens for women at high risk for breast cancer. A high risk for breast cancer is typically because of a strong family history. A strong family history is usually a mother or sister who has had breast cancer before age 50. It can also be aunts or cousins, including those on your father’s side. Relatives who have had ovarian cancer also increase your risk. Your radiologist or primary care doctor can look at your family history and determine if MRI screening may be appropriate for you.
Breast MRI may be performed to:
- Check for more cancer in the same breast or the other breast after breast cancer has been diagnosed
- Distinguish between scar tissue and tumors in the breast
- Evaluate a breast lump (usually after biopsy)
- Evaluate an abnormal result on a mammogram or breast ultrasound
- Evaluate for possible rupture of breast implants
- Find any cancer that remains after surgery or chemotherapy
- Screen for cancer in women at high risk for breast cancer (such as those with a strong family history)
- Screen for cancer in women with very dense breast tissue
An MRI of the breast can also show:
- Blood flow through the breast area
- Blood vessels in the breast area
- Breast MRI is more sensitive than mammogram, especially when it is performed using contrast dye. However, breast MRI may not always be able to distinguish breast cancer from noncancerous breast growths. This can lead to a false positive result.
- MRI also cannot pick up tiny pieces of calcium (microcalcifications), which mammogram can detect.
- A biopsy is needed to confirm the results of a breast MRI.
Before the Test
- If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician for a prescription for a mild sedative prior to the scheduled examination. If sedation is used, it is required that you arrange for a relative or friend to drive you home after the exam.
- Report any allergies to the technologist.
- Women should always inform the technologist if there is any possibility that they are pregnant.
- If IV contrast will be used, patients over the age of 50 years old require a blood test within the past 30 days to measure their Creatinine level.
- Jewelry and other accessories should be left at home, or removed prior to the MRI scan. Because they can interfere with the magnetic field of the MRI unit, metal and electronic objects are not allowed in the exam room.
- Let your technologist know if you have:
- a pacemaker, aneurysm clips, vascular coils, or filters
- inner ear implants or hearing aids
- unremoved shrapnel or bullet fragments
- insulin or other infusion pumps
- permanent dentures
- worked around metal and/or have had fragments in your eye(s)
- surgical shunts
- heart valves
- metal plates, rods, pins or screws
- joint replacements
- surgical staples or wires
- No food or drink for 2 hours prior to exam
During the Test
- If an intravenous contrast material is used, you will feel a pin prick when the needle is inserted into your vein. Some patients may sense a temporary metallic taste in their mouth after the contrast injection.
- You will lie face down on a platform specially designed for the procedure. The platform has openings to accommodate your breasts and allow them to be imaged without compression.
- Be sure to let the technologist know if something is uncomfortable, since discomfort increases the chance that you will feel the need to move during the exam.
- You will be moved into the magnet of the MRI unit and the technologist will perform the examination while working at a computer outside of the room.
- It is important that you remain perfectly still while the images are being obtained. You will know when images are being recorded because you will hear and feel loud tapping or thumping sounds. Earplugs or headphones are provided to reduce the intensity of the sounds made by the MRI machine.
- The entire examination is usually completed within 45-60 minutes.
After the Test
- There are no restrictions after a MRI scan. You should be able to resume your normal activities immediately.
- A report from today’s exam will be sent to your doctor within 3 days.