A mammogram uses a very small amount of radiation, typically around 0.4 millisieverts (mSv) per exam. This dose is considered low and is carefully controlled to minimize exposure while still providing clear images for detecting breast cancer. For context, the average person in the United States receives about 3 mSv of radiation annually from natural background sources, so a mammogram contributes only a fraction of that amount.
Mammography is a specialized form of X-ray imaging designed specifically for breast tissue. It uses low-dose X-rays to create detailed images that can reveal tumors or other abnormalities that might not be felt during a physical exam. The radiation dose is kept as low as reasonably achievable, following a principle known as ALARA, to ensure patient safety without compromising diagnostic quality.
The procedure usually involves taking two views of each breast, with each view requiring compression of the breast for about 10 seconds. This compression helps spread out the tissue for a clearer image and reduces the amount of radiation needed. The entire process is quick, and the discomfort from compression is brief.
Advancements like 3D mammography, or digital breast tomosynthesis, use multiple X-ray images from different angles to create a more complete picture of the breast. This technique can detect invasive cancers more effectively and reduce unnecessary callbacks. Importantly, 3D mammography still uses a similarly low dose of radiation as traditional 2D mammograms.
While any exposure to radiation carries some risk, the amount used in mammograms is very small compared to everyday sources of radiation, such as cosmic rays during air travel or natural background radiation. The benefits of early breast cancer detection through mammography far outweigh the minimal radiation risk involved.
Women are generally advised to begin regular mammogram screenings around age 40, with frequency depending on individual risk factors like family history. For those at higher risk, additional imaging methods such as breast MRI or ultrasound may be recommended alongside mammograms.
In summary, a mammogram involves a carefully regulated, low dose of X-ray radiation—about 0.4 mSv per exam—designed to maximize early detection of breast cancer while minimizing radiation exposure. This balance ensures that mammography remains a safe and effective tool in breast health screening.
