Mammograms are x-rays of the breasts. These x-rays are used to look for breast cancer. Breast cancer often develops as a lump (mass), calcifications(tiny deposits of calcium) or distortion of the tissue. Mammograms are very good at showing these abnormalities as different from normal background breast tissue.
A very important part of mammogram evaluation is comparison of previous and current pictures. Breast tissue patterns generally remain static from year to year. Any changes may signal cancer development.
The fact that mammograms are so sensitive in picking up breast cancers, while at the same time being minimally invasive, means that it is practical to use the examination as a cancer screening test.
A screening test is a test used in a supposedly healthy population in order to identify cancers very early on. The key to a screening test is to do it regularly enough that very few cancers will grow between tests. In the case of breast cancer, mammograms done once yearly are optimal.
Mammograms are evaluated by radiologists. A radiologist is a medical doctor who has specialized in imaging of the body i.e. x-rays, ultrasounds, CT scans and MRI scans.
Normal mammogram picture. The Black area is fat. The white areas are breast tissue – mainly glands and fibrous tissue. Everyone has a different proportion of fat to breast tissue. Two views of both right and left breasts.