Radiation is always a concern when people need some type of medical imaging. This holds true with mammography and can lead to questions since this important screening is recommended every year for women over 40. Patients often ask if mammograms are safe and how they can evaluate the amount of radiation they will receive during this procedure.
Understanding radiation from mammograms
Today, modern mammography equipment produces high quality breast images with low doses of radiation. Using a standard measure of radiation dose, milliSievert (mSv), the total dose for a screening mammogram with two views of each breast (four images total) is about 0.4 mSv.
To put that number in perspective, people in the US are typically exposed to an average of about three mSv of radiation each year from background sources such as natural surroundings. The radiation dose a woman receives with a screening mammogram is about equal to the dose received over seven weeks from natural surroundings or background radiation.
Common sources of background radiation are radioactive minerals in the ground and cosmic radiation arriving from space. For comparison purposes, the radiation dose from a mammogram is a little more than from a chest x-ray, but less than the exposure from the radon present in the average home or the relative annual increase in cosmic radiation exposure from living in a high altitude city like Denver. It is much less than the dose delivered during a barium x-ray study of the abdomen or a CT scan.
Mitigating radiation risks
Wake Radiology’s outpatient imaging offices have been designed as centers of excellence by the American College of Radiology. Part of earning that distinction involves following specific guidelines and conducting frequent equipment inspections to ensure that our equipment is safe and uses the lowest radiation dose possible to produce high quality, diagnostic images. Our breast imaging offices have also been named Breast Imaging Centers of Excellence (BICOE) by the ACR.
The level of radiation in today’s mammograms does not increase the risk of breast cancer for women who get regular, annual mammograms. Additionally, a mammogram is the best way to detect breast cancer early – even before it can be identified during physical exam. The benefits of early detection and treatment outweigh any possible harm from the very low dose radiation exposure.
It’s important to let your mammogram technologist know if you’re pregnant or think you may be pregnant. Although the risk to the fetus is likely very small, screening mammograms are usually not conducted in pregnant patients. When pregnant patients have a concerning physical exam, we often perform a breast ultrasound which has no ionizing radiation, with mammography only done afterwards, if needed.
Understanding radiation from 3D mammograms
Wake Radiology is proud to be the leading provider of 3D mammography in the greater Triangle. We now offer 3D mammography in Raleigh, Cary, Chapel Hill and Garner. This is a revolutionary breakthrough in breast cancer detection that takes more images of the breast. For that reason, 3D mammograms do give a slightly higher overall radiation dose, on the order of 0.5 to 1.0 mSv.
Even with that increase over a traditional mammogram, we believe that the technology associated with 3D mammography offers the promise of more accurate detection of breast abnormalities, particularly in patients with dense breasts. The more comprehensive images likely mean that additional images of the breast are not necessary so that the overall radiation exposure is actually less.