Since it’s breast cancer awareness month, let’s talk about mammograms.
Mammography uses low-energy X-rays to detect breast cancer, typically through detection of characteristic masses or microcalcifications.
About seven percent of women screened have a “false positive” and receive further testing. (I’ve had this twice.) Mammography can also miss cancer and have a “false negative” reading for about ten percent of those screened.
Ultrasound is used for further evaluation of masses found on mammography. Other detection tools include ductography, positron emission mammography (PEM) and magnetic resonance imaging (MRI). Researchers are investigating other procedures, including tomosynthesis.
Digital mammography uses digital receptors and computers instead of X-ray film. The resulting computer-screen images permit more manipulation so radiologists can review the results more clearly. This technology is a spin-off of that developed by NASA for the Hubble Space Telescope.
3D mammography or digital breast tomosynthesis (DBA) creates a 3D image of the breast using X-rays When used in addition to usual mammography, it results in more positive tests, but it more than doubles the radiation exposure.
Mammography can trace its history back to the discovery of X-rays by Wilhelm Rontgen in 1895. In the late 1950s, Robert Egan devised a method of screening mammography for the first time. Use of the “Egan technique” spread after a 1966 study demonstrated the impact of mammograms on mortality and treatment.
A 2016 review of the United States Preventative Services Task Force found that mammography results in an eight to thirty-three percent decrease in breast cancer mortality in different age groups. It currently recommends mammography every two years between the ages of 50 and 74.