Breast MRI Used to Detect Breast Cancer in Baltimore

Unlike mammography, which produces images using X-rays, breast MRI (magnetic resonance imaging) creates images using highly magnetic fields and radiofrequency waves to produce detailed cross sectional images of the breasts, underarm (axillary) regions and chest wall structures. 

A major difference of a breast MRI is that it detects cancers mainly by detecting physiologic differences in the tissue related to increased blood supply (neo-angiogenesis) which is typically present in cancerous tissue. This is accomplished by IV injection of a contrast agent (gadolinium) which is then detected as bright areas (enhancement) on the images, signaling regions of increased blood flow which might indicate cancerous tissue.

Breast is intended to be used in addition to mammography and breast ultrasound and not as a replacement. It is most commonly used for screening high-risk patients to detect cancer early and to evaluate the extent of disease in patients with known breast cancer to help develop the most appropriate treatment plan. 

There are very specific indications for the use of breast MRI and these can be divided into screening breast MRI and diagnostic (or problem-solving) types of exams.

Screening Breast MRI is indicated for patients who are considered “high-risk” for breast cancer:

• Women with a personal or family history of genetic predisposition to develop breast cancer (genetic mutation carriers such as BRCA1/BRCA2 or other disease-causing mutations)
• Women with a calculated estimated lifetime breast cancer risk of 20% or more (as determined by the Cancer Risk Assessment)
• Women with a personal history of high dose radiation treatment to the chest prior to age 30 (such as treatment for Hodgkin's lymphoma)

Screening Breast MRI could also be considered appropriate in these cases (insurance coverage may vary):

• Women with a personal history of breast cancer and very dense breast tissue
• Women diagnosed with breast cancer prior to age 50 and treated with breast-conserving surgery
• Women with a history of LCIS or atypia (ADH, ALH, atypical papilloma) on prior breast biopsy, especially if they also have other risk factors related to family history

Diagnostic Breast MRI is performed as a problem solving exam used for the following indications:

• Evaluation of patients newly diagnosed with breast cancer, to evaluate the extent of the disease and determine the most appropriate surgical treatment
• Evaluation of a breast cancer patient’s response to chemotherapy
• Post-operative evaluation after lumpectomy in patients with positive surgical margins
• Patients diagnosed with metastatic breast cancer at a site such as a lymph node or distant organ, with no visible cancer in the breast on mammography or ultrasound
• To help distinguish between scar tissue and recurrent cancer in patients with prior breast cancer
• Problem-solving exam in the setting of an inconclusive mammogram/ultrasound (MRI is very rarely recommended for this reason)
• Evaluation of breast implants for possible rupture

There are several considerations to take into account when scheduling a breast MRI exam:

• Schedule the exam at the appropriate time of your menstrual cycle. The first day of menstrual bleeding is considered day #1 of your cycle. If you are pre-menopausal, we request that the MRI exam be scheduled between days 7 and 14 of the cycle. This is to prevent excessive enhancement of the tissue due to hormonal changes which might limit the ability to detect cancer.
• Inform your doctor if you have any history of kidney problems. The dye used for the MRI may cause problems in patients with kidney disease. You may be required to have a blood test to check your kidney function prior to the exam to be sure that the dye is safe for you.
• Tell your doctor if you are or could be pregnant. MRI is generally not recommended in pregnancy.
• Tell your doctor if you have any allergies to help avoid any complications with the IV contrast agent.
• Tell your doctor about any implanted medical devices such as a pacemaker, defibrillator, etc., which might not allow the MRI to be performed.
• If you have a history of claustrophobia, you may want to request that your doctor prescribe a mild sedative to be taken just prior to the exam.
• If you are nursing, The American College of Radiology states that the risk to your baby from the contrast agent is extremely low. If you are still concerned, you may consider discarding your breast milk for 12-24 hours after the exam. In this case, you could pump and store milk before the procedure.

Prior to the MRI exam, an IV line will be placed in your arm to administer the contrast agent (gadolinium) which helps detect abnormalities in the tissue.

The MRI machine has a large central opening. For the exam, which typically lasts 20-30 minutes, you will be positioned face-down on a padded scanning table with your breasts suspended in a cushioned depression in the table. 

The table will then slide into the machine and you will be asked to lie still and breathe normally for the duration of the exam. This produces the best quality images with no motion blurring (artifact). 

The MRI machine creates a magnetic field around you and radio waves are directed at your body. You will not feel the magnetic or radio waves, but you will likely hear tapping and thumping sounds during different parts of the exam.

You will be offered ear plugs and headphones with music to help alleviate this noise. During the exam, the MRI technologist will be monitoring you from an outside room and you will be able to speak with the technologist via a microphone in the scanner.

A typical Breast MRI produces approximately 2500 images of the breasts, which are then interpreted by our breast imaging radiologists.

After your exam is reviewed by one of our breast imaging radiologists, a full report of the findings will be sent to your referring physician who will contact you to discuss the results and any recommendations.

MRI is a very sensitive test for detecting breast cancer, but it is not extremely specific. This means findings may be identified that, after further evaluation with ultrasound or biopsy, turn out to be benign (not cancer). If a finding is identified on MRI, we will work with your doctor to arrange any additional testing required in a timely manner.

Breast MRI is typically considered a very safe procedure that does not expose your body to radiation. As with any imaging test or medical procedure, there are some risks that exist and should be discussed with your physician to determine if this is an appropriate test for you:

• Risk of false positive result – An MRI may identify findings that require additional evaluation, including possible biopsy to determine if the area of concern is benign (non-cancerous) or malignant (cancerous).
• Risk of allergic reaction to the contrast dye (gadolinium) such as hives - In extremely rare instances, a severe allergic reaction could lead to breathing difficulties and/or shock. Our physicians and staff are trained to recognize and treat these reactions.
• Risk of side effects of contrast dye – These may include nausea, headache, change in sense of taste, feeling hot and burning at the injection site.
• Risk of Nephrogenic System Fibrosis (NSF) – This is a very rare condition which can develop from gadolinium injection and causes severe thickening of the skin, muscles and other body organs. This only occurs in patients with kidney problems and is why your provider will screen you to determine how well your kidneys are working prior to ordering breast MRI with contrast.
• Retention of gadolinium in the body – Small amounts of the metal gadolinium, which is part of the IV contrast solution, have been shown to stay in the body in the brain, bones, skin and other sites for several months to years. Although it is not completely known how retained gadolinium may affect you, studies so far have shown no harmful effects in patients with normal kidneys. Patients who have received many doses of gadolinium contrast may have increased risk from retention.