Mammograms and Other Breast Imaging Tests

+ -Text Size


How is a mammogram done?

When you have a mammogram, your breast is briefly compressed or squeezed between 2 plates attached to the mammogram machine—an adjustable plastic plate (on top) and a fixed x-ray plate (on the bottom). The bottom plate holds the x-ray film or the digital detector that records the image. The technologist compresses your breast to keep it from moving, and to make the layer of breast tissue thinner. A thinner layer of breast tissue allows the x-ray exposure to be reduced and makes the picture sharper. Although the compression can feel uncomfortable and even painful for some women, it is needed to get a good picture and only lasts the few seconds needed to take the x-ray. Talk to the technologist if you have pain. She can reposition you to make the pressure as comfortable as possible.

The procedure produces a black and white image that is read by a radiologist (a doctor trained to interpret images from x-rays, ultrasound, magnetic resonance imaging, and related tests.)

When mammography was first developed, the image was recorded on film. More often now, the image is recorded on a computer instead. This is called a digital mammogram (also known as a full-field digital mammogram or FFDM). Digital mammograms may be better than film mammograms at finding cancers in women younger than 50 and in women with dense breast tissue. In the United States, most mammograms are digital.

A newer type of mammography is known as breast tomosynthesis or 3D mammography. For this test, the breast is compressed once and a machine takes many low-dose x-rays as it moves over the breast in an arc. The images can then be combined by a computer into a 3-dimensional picture. This uses more radiation than most standard 2-view mammograms, but it may allow doctors to see the breast more clearly. Some studies have suggested it might lower the chance of being called back for follow-up testing. It may also be able to find more cancers.

Not all health insurance covers tomosynthesis, so you may want to check with your insurance company if this is recommended for you.

Last Medical Review: 12/08/2014
Last Revised: 10/20/2015