Magnetic resonance imaging, or MRI, uses magnets and radio waves to make very precise cross-sectional pictures of the body. For breast MRI, you will lay face-down in a narrow tube with openings for your breasts. These openings allow the imager to take photos of the breasts without pressing on them. The process can take up to an hour. You may be injected with a contrast material to improve the quality of the images. To ensure the quality of the images, it is very important for you to remain still for the duration of the process.