Magnetic resonance imaging (MRI) of the breast is a common medical test. It detects breast cancer and other breast conditions. A breast MRI takes layered images of your breast. A computer combines these images and turns them into detailed pictures.
Doctors usually order a breast MRI after you have a biopsy that’s positive for cancer. They give your doctor more information about the extent of the disease. Sometimes, like if you have a high risk of breast cancer, your doctor may order a breast MRI along with a mammogram. Together, these are an effective screening tool for detecting breast cancer.
An MRI is a noninvasive medical test, which means that it doesn’t break the skin. It helps doctors diagnose and treat illness and disease. MRI uses a strong magnetic field, radio frequency pulses, and a computer to take pictures of the body. It can make detailed pictures of almost anything inside your body, like organs, soft tissues, bones. MRI does not use radiation, like x-rays.
MRI of the breast gives your doctor important information about many breast conditions. It works well for conditions when other tests don’t, like mammograms or ultrasound.
A breast MRI doesn’t replace mammograms or ultrasounds. Instead, it’s used in addition to them. Here are some reasons your doctor might order an MRI.
If you have strong family history of breast cancer, your doctor may order a breast MRI to screen for it. Your radiologist or primary care doctor can look at your family history and decide if a screening MRI is right for you.
If you’ve just been diagnosed with breast cancer, your doctor may order a breast MRI to stage the cancer, or see if it has spread. For example, it can show if the cancer is in the underlying muscle, how many tumors are in the breast, whether there is cancer in the opposite breast, and if it’s spread to the lymph nodes.
Sometimes mammograms and ultrasounds can’t show you everything about your condition. In these rare cases, doctors use an MRI to determine if you need biopsy or the issue can safely be left alone.
If cancer comes back, it can look like scars on a mammogram or ultrasound. So, if your scars change, MRI can tell your doctor whether the change is normal, or the cancer has come back.
This means you had chemo before surgery to remove the tumor. In these cases, MRI can show how well the chemotherapy is working. It can also show how much of the tumor is still present before you have surgery.
MRI is the best test for determining whether silicone implants have ruptured.
Breast MRI examinations require the patient to receive an injection of MRI contrast material into the bloodstream. The traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table that slides into the center of the magnet. The computer workstation that processes the imaging information is located in a separate room from the scanner.
Most MRI exams are painless. However, some patients find it uncomfortable to remain still during MRI imaging. Others experience a sense of claustrophobia. Patients who anticipate anxiety can be sedated, but fewer than one in 20 require medication. You will be offered earplugs to reduce the noise of the MRI scanner, which produces loud thumping and humming noises during imaging.
Yes, you should stay as still as possible during the test. The technologist will position you on the moveable examination table. They may use bolsters to help you stay still and hold the correct position during imaging.
For an MRI of the breast, you will lie face down on a platform specially designed for the procedure. Openings in the platform make room for your breasts and let them to be imaged without compression, or pressure. The electronics needed to capture the MRI image are actually built into the platform. It is important to remain still throughout the exam, so make sure you are comfortable and can relax. Be sure to let the technologist know if something is uncomfortable, since discomfort increases the chance that you will move during the exam.
A nurse or technologist will insert an intravenous catheter, also known as an IV line, into a vein in your hand or arm. The machine will then move you to the magnet of the MRI unit. The technologist will do the examination while they work at a computer outside of the room. They will take the first series of scans and then inject your IV line with contrast material. The machine will take more images after the injection. When they finish the exam, they may ask you to wait until the technologist or radiologist checks the images. This will let them take more images, if needed. Once they have the images they need, the technologist will remove your IV line.
MRI exams generally include multiple runs, some of which may last several minutes. The imaging session lasts 30 minutes to an hour.
A breast radiologist, a physician specifically trained to supervise and interpret your examination, will analyze the images and send a report to your primary care or referring physician, who will share the results with you.
Follow-up examinations may be necessary, and University Breast Care will contact you and explain why another exam is requested. Sometimes your doctor will ask for a follow-up exam, because they need clarification on an image. They do this with additional views or a special imaging technique.
As with many medical tests, MRIs cary both benefits and risks. For example, here are some of the benefits:
In addition, here are some of the risks:
A breast MRI can tell your doctor more about your breast cancer or breast cancer risk. But the tests do have some limitations.
For example, they can only take high-quality images if you remain perfectly still during the test. If you’re anxious, confused or in severe pain, it might be hard to lie still during imaging. Here are some other things that might affect your test: