Magnetic resonance imaging (MRI) of the breast

Magnetic resonance imaging (MRI) of the breast

MRI scans use radio waves and strong magnets instead of x-rays. The energy from the
radio waves is absorbed and then released in a pattern formed by the type of body tissue
and by certain diseases. A computer translates the pattern into a very detailed image of
parts of the body. For breast MRI to look for cancer, a contrast liquid called gadolinium
is injected into a vein before or during the scan to show details better.
MRI scans can take a long time—often up to an hour. You have to lie inside a narrow
tube, face down on a platform specially designed for the procedure. The platform has
openings for each breast that allow them to be imaged without compression. The platform
contains the sensors needed to capture the MRI image. It is important to remain very still
throughout the exam.
Lying in the tube can feel confining and might upset people with claustrophobia (a fear of
enclosed spaces). The machine also makes loud buzzing and clicking noises that you may
find disturbing. Some places will give you headphones with music to block this noise out.
MRIs are also expensive, although insurance plans generally pay for them in some
situations, such as once cancer is diagnosed.
MRI machines are quite common, but they need to be specially adapted to look at the
breast. It's important that MRI scans of the breast be done on one of these specially
adapted machines and that the MRI facility can also do a MRI guided biopsy if it is
needed.
MRI can be used along with mammograms for screening women who have a high risk of
developing breast cancer, or it can be used to better examine suspicious areas found by a
mammogram. MRI is also used for women who have been diagnosed with breast cancer
to better determine the actual size of the cancer and to look for any other cancers in the
breast. It is not yet clear how helpful this is in planning surgery in someone known to
have breast cancer. In someone known to have breast cancer, it is sometimes used to look
at the opposite breast, to be sure that it does not contain any tumors.
If an abnormal area in the breast is found, it can often be biopsied using an MRI for
guidance. This is discussed in more detail in the "Biopsy" section.