<unk>  (also called mastography) is the process of using low-energy X-rays (usually around 30 kVp) to examine the human breast for diagnosis and screening. The goal of<unk>  is the early detection of breast cancer, typically through detection of characteristic masses or microcalcifications. As with all X-rays, mammograms use doses of ionizing radiation to create images. These images are then analyzed for abnormal findings. It is usual to employ lower-energy X-rays, typically Mo (K-shell X-ray energies of 17.5 and 19.6 keV) and Rh (20.2 and 22.7 keV) than those used for radiography of bones. Ultrasound, ductography, positron emission<unk>  (PEM), and magnetic resonance imaging (MRI) are adjuncts to<unk> . Ultrasound is typically used for further evaluation of masses found on<unk>  or palpable masses not seen on mammograms. Ductograms are still used in some institutions for evaluation of bloody nipple discharge when the mammogram is non-diagnostic. MRI can be useful for further evaluation of questionable findings, as well as for screening pre-surgical evaluation in patients with known breast cancer, in order to detect additional lesions that might change the surgical approach, for example, from breast-conserving lumpectomy to mastectomy. Other procedures being investigated include tomosynthesis. For the average woman, the U.S. Preventive Services Task Force recommends (2016)<unk>  every two years between the ages of 50 and 74, concluding that "the benefit of screening<unk>  outweighs the harms by at least a moderate amount from age 50 to 74 years and is greatest for women in their 60s". The American College of Radiology and American Cancer Society recommend yearly screening<unk>  starting at age 40. The Canadian Task Force on Preventive Health Care (2012) and the European Cancer Observatory (2011) recommend<unk>  every 2 to 3 years between ages 50 and 69. These task force reports point out that in addition to unnecessary surgery and anxiety, the risks of more frequent mammograms include a small but significant increase in breast cancer induced by radiation. Additionally, mammograms should not be performed with increased frequency in patients undergoing breast surgery, including breast enlargement, mastopexy, and breast reduction. The Cochrane Collaboration (2013) concluded after ten years that trials with adequate randomization did not find an effect of<unk>  screening on total cancer mortality, including breast cancer. The authors of this Cochrane review write: "If we assume that screening reduces breast cancer mortality by 15% and that overdiagnosis and over-treatment is at 30%, it means that for every 2,000 women invited for screening throughout 10 years, one will avoid dying of breast cancer and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily. Furthermore, more than 200 women will experience important psychological distress including anxiety and uncertainty for years because of false positive findings." The authors conclude that the time has come to re-assess whether universal<unk>  screening should be recommended for any age group. They state that universal screening may not be reasonable. The Nordic Cochrane Collection updated research in 2012 and stated that advances in diagnosis and treatment make<unk>  screening less effective today, rendering it "no longer effective". They conclude that "it therefore no longer seems reasonable to attend" for breast cancer screening at any age, and warn of misleading information on the internet. On the contrary, a report in the New England Journal of Medicine attributes the poor effectiveness of national<unk>  screening programs at reducing breast cancer mortality to radiation-induced cancers.<unk>  has a false-negative (missed cancer) rate of at least ten percent. This is partly due to dense tissue obscuring the cancer and the appearance of cancer on mammograms having a large overlap with the appearance of normal tissue. A meta-analysis review of programs in countries with organized screening found a 52% over-diagnosis rate.
Mammography
Xeromammography
Breast MRI
Scintimammography
Breast imaging
Breast biopsy
Breast ultrasound
Breast self-examination