Breast Cancer – Diagnostics – Mammography
Mammography is a special X-ray examination of the breast.
The advantage: Mammography can detect small early-stage tumors that cannot be felt by touch.
In many countries, mammography is a part of their national cancer screening programs. During a mammography screening, the breast is positioned between the X-ray tube and a detector. While the image is being taken, the breast is, for a short while, carefully pushed down with a compression plate.
Many women find this pressure unpleasant and sometimes even painful. It is, however, necessary in order to get a conclusive image with the right level of quality, and it is reduced to an individually calculated minimum. Compression also lowers the exposure to radiation.
Mammography images especially detect what is called microcalcification. Microcalcifications may indicate tissue changes and thus, a preliminary form of cancer, or a malignant tumor. The medical practitioner analyzes the radiographic images, looking for anything suspicious, such as lighter patches, which are caused by this microcalcification.
Each breast is X-rayed at least twice – once from top to bottom and once diagonally from the outside in. The exposure to radiation is low and below internationally specified radiation limits. In any case the benefit of breast cancer detection outweighs the risk of radiation-induced cancer caused by multiple X-ray exposures over a long time.
Analog and digital methods
As with photography, there are two different types of mammography: With the analog method, the X-rays expose an image onto film, while with the digital method the X-rays hit a special detector, which calculates and interprets the image data. The result is a black-grey-white radiographic image: Those rays that penetrate the tissue blacken the X-ray film. The areas that cannot be penetrated remain white.
Mammography is sometimes offered as part of cancer screening programs. Screenings are medical examinations that are performed on a regular basis on eligible persons. Screening programs may be implemented by governments and may take place in screening centers specially designed for the purpose. The tests are carried out by a registered radiology technician, and generally analyzed by a physician.