Mammograms use a very low dose of X-rays to create images of breast tissue. This imaging procedure is an effective diagnostic tool for detecting breast cancer. Medical professionals consider mammograms safe and beneficial for early detection, despite the use of radiation.
How Mammograms Utilize Radiation
Mammograms use X-rays to visualize the internal structures of the breast. The mammography machine is designed to focus X-ray beams on breast tissue, using lower doses compared to X-rays for other body parts. During the procedure, the breast is gently compressed between two plates. This compression helps spread out the tissue and ensures a clearer image with less radiation exposure.
X-rays pass through the breast and are captured by a detector, which can be a photographic film plate or a solid-state detector. Solid-state detectors convert X-rays into electronic signals, which a computer processes into digital images. Digital mammography has reduced radiation exposure compared to older film-based methods. This technology also offers advantages like enhanced image contrast and the ability to easily share images for second opinions.
Quantifying Radiation Exposure
The amount of radiation from a typical mammogram is small, often measured in millisieverts (mSv). A standard mammogram with two views of each breast delivers an average total dose of about 0.4 mSv. For perspective, people are naturally exposed to an average of about 3 mSv of background radiation each year from their surroundings. This means a single mammogram is roughly equivalent to the natural radiation a person receives over about seven weeks.
Comparing it to other common exposures, a three-hour airplane flight might expose a person to about 0.1 mSv, and a single chest X-ray delivers around 0.1 mSv. The radiation dose from a mammogram is less than that of a standard chest X-ray and significantly lower than more extensive imaging procedures like a CT scan of the abdomen, which can expose a person to about 10 mSv. Low doses used in mammography are not associated with negative health effects, with studies showing increased cancer risk only at doses above 100 mSv.
The Importance of Mammography Screening
Mammograms are important for the early detection of breast cancer. Finding breast cancer early, before symptoms appear, improves treatment outcomes and survival rates. For instance, localized breast cancer detected early has a 5-year survival rate of approximately 99 percent.
Early detection allows for less aggressive and invasive treatment options. Regular screening mammograms can identify small, potentially cancerous changes, such as microcalcifications. The reduction in breast cancer mortality, estimated to be around 20 percent, is attributed to mammography screening. The benefits of early diagnosis and improved survival rates outweigh the minimal risks associated with low-dose radiation exposure from mammograms.