A mammogram is an x-ray of the breast. A diagnostic mammogram is used to diagnose breast disease in women who have symptoms or an abnormal result on a screening mammogram. Screening mammograms are used to look for breast disease in women who are asymptomatic; that is, they appear to have no breast problems. Screening mammograms usually take two views (x-ray pictures taken from different angles) of each breast. For some patients, such as women with breast implants, more pictures may be needed to include as much breast tissue as possible. Women who are breast-feeding can still get mammograms, but these are probably not quite as accurate because the breast tissue tends to be dense.Strict guidelines ensure that mammogram equipment is safe and uses the lowest dose of radiation possible. To put dose into perspective, if a woman with breast cancer is treated with radiation, she will receive around 5,000 rads, if she had yearly received 20 to 40 rads.
For a mammogram, the breast is pressed between two plates to flatten and spread the tissue. This may be uncomfortable for a moment, but is necessary to produce a good, readable mammogram. The compression only lasts a few seconds. The entire procedure for a screening mammogram takes about 20 minutes. A black and white image of the breast tissue is obtained either on a large sheet of film or as a digital computer image that is read, or interpreted, by a radiologist (a doctor trained to interpret images from x-rays, ultrasound, MRI, and related tests).In females with very dense breasts or with cysts, ultrasound mammograms, nuclear mammograms called scintimammograms or MRI mammography may be advised. These are painless techniques and are reserved for specific cases and not used routinely.