Breast ultrasound has many uses in the assessment of breast health. Some women wonder whether they can or should have breast ultrasound for screening instead of mammography, but mammography remains the primary screening test for breast cancer in the general population (1) as recommended by the Canadian Association of Radiologists (CAR).
When do we recommend breast ultrasounds?
Your primary care physician may ask for a breast ultrasound in some situations, or your radiologist may add on a breast ultrasound when you come in for a mammogram. According to the Canadian Association of Radiologists, some of the indications for breast ultrasound in the general population include investigating something that you or your doctor feel in your breast or further characterizing findings that are seen on a screening mammogram (1). In fact, breast ultrasound may be used before or even without mammogram in some situations, such as in women who are pregnant, breastfeeding, or under the age of 30. Breast ultrasound is also used to provide guidance for the Radiologist during procedures in the breast for both diagnostic purposes such as a biopsy or treatment purposes such as removing the fluid from a cyst if they are large or painful, or draining an infection
In women who have dense breasts (that is, more glandular tissue – the tissue that makes breast milk – than fat), whole breast ultrasound using tools like 3D automated breast ultrasound (ABUS) has been suggested as a screening tool to assess denser breasts. ABUS has recently been approved by Health Canada. Like a polar bear in a snow storm, it can sometimes be hard to see small masses superimposed on dense breast tissue on mammography. Breast ultrasound may be able to find these.
Why not use breast ultrasound for all women?
However, breast ultrasound is not recommended for screening the general population, for many reasons including time and additional resources needed for breast ultrasound (2). The Canadian Association of Radiologists still recommends mammography as the main screening tool for all women, regardless of breast density, and breast ultrasound can be used with mammograms if needed, but not on its own (1, 2, 3). Even in women with an increased risk of breast cancer (including patient age, significant family history, genetic markers and prior chest radiation), breast MRI is recommended for supplemental screening with mammography, rather than ultrasound.
What are the disadvantages of using breast ultrasounds?
While including breast ultrasound in screening can help find small cancers in the breast, it can also increase your chance of being brought back to the Radiologist’s office for more imaging, and/or getting a biopsy that may not turn out to be cancer (called a false positive) (2, 4). This is important, as any biopsy carries a small risk of bleeding, bruising or causing an infection. Not to mention the stress and worry it can cause before and during the procedure, and waiting for the pathology results to come back. Therefore, it is important to talk with your primary care physician, as well as your radiologist, about getting screening breast ultrasound and possible outcomes.
This post was co-written by Dr. Alyzee Sibtain, MD, FRCPC and Dr. Amie Padilla-Thornton, MD, FRCPC. Dr. Sibtain and Dr. Padilla-Thornton are radiologists with special interests in breast imaging, Dr. Sibtain practices in Alberta, Canada and Dr. Padilla-Thornton practices in British Columbia, Canada.
1. Appavoo S, Aldis A, Causer P, et al. CAR Practice Standards and Technical Guidelines for Breast Imaging and Intervention. Ottawa, Ontario: Canadian Association of Radiologists 2016. https://car.ca/wp-content/uploads/car_breastimagingguidelines_2016_en.pdf
2. CAR/CSBI Position Statement on Mammographic Breast Density and Supplemental Screening . https://car.ca/wp-content/uploads/2019/07/CAR-CSBI-Breast-Density-Position-Statement-En.pdf June 2019.
3. Hooley RJ, Scoutt LM, Philpotts LE. Breast Ultrasonography: State of the Art. Radiology 2013 268 (3): 642-659.
4. Lee JM, Arao RF, Sprague BL, et al. Performance of screening ultrasonography as an adjunct to screening mammography in women across the spectrum of breast cancer risk. JAMA Intern Med 2019;179(5):658-667.