WHEN IS BREAST ULTRASOUND ORDERED?

Mammography is the gold standard for breast cancer screening. Unlike mammography, breast ultrasound in isolation is NOT authorized by the College of Physicians and Surgeons of Alberta as a screening tool for early detection of breast cancer. This applies to both handheld and automated breast ultrasound.

Breast ultrasound is considered a diagnostic tool. This means that it’s ordered to investigate a specific concern, either to identify a cause for symptoms, such as lumps, pain, or redness, or if a doctor has discovered an abnormality.

Screening describes routine imaging that is ordered without specific symptoms or concerns, such as annual mammograms. It can be used to help detect diseases before they cause symptoms and while they can still be successfully treated.

BREAST ULTRASOUND AND BREAST DENSITY

Your breasts are made up of different types of tissue: fibroglandular and connective tissue, and fat. At Mayfair Diagnostics mammography clinics our equipment has software that helps determine your breast density – a measure of the proportion of fatty (not dense) versus connective and fibroglandular (dense) tissue that make up your breast. Breast density does NOT have to do with the size, look, or feel of your breast.

For women, breast density is the most prevalent risk factor for breast cancer. Sometimes a breast ultrasound may be performed along with your screening mammogram, if you meet the criteria below:

• A mammogram indicates you have extremely dense breast tissue (Volpara D).
• A mammogram indicates you have heterogeneously dense breast tissue (Volpara C) AND your medical and/or family history puts you at high risk for breast malignancy.

If a breast ultrasound is ordered because you meet the above criteria, your breast ultrasound would still be considered diagnostic, even if it’s ordered annually along with your screening mammogram.

If you do not meet the criteria above, then Mayfair Diagnostics is not authorized to perform a breast ultrasound along with your mammogram, even if your doctor has requested it or checked off Complete Breast Assessment on the Mayfair general requisition.

Please note that your breast density can change, so you may have a breast ultrasound with your mammogram one year but not the next.

SCREENING MAMMOGRAPHY AND BREAST CANCER

Having regular screening mammograms makes it easier to compare images and see changes that are too small for you or your doctor to feel. These exams can be requested for women 40 and over when there are no symptoms, as part of a breast screening program. The Alberta Health Insurance Plan covers one screening mammogram per year for women, starting at age 40.

Breast cancer will affect one in eight women in Canada, but if you find it early, there is less chance of recurrence and an increased chance that it has not spread to the lymph nodes, so the odds are better you will survive it. Thanks to preventative screening more women are surviving a breast cancer diagnosis. In 2017, 89% of women diagnosed with breast cancer were still alive after five years.

During a screening mammogram, four images are taken. Occasionally you may be asked to return for additional breast imaging, such as a diagnostic mammogram and/or diagnostic breast ultrasound. This is done to get a more detailed look at any areas of concern and ensure you have received a complete breast exam.

HIGH RISK FACTORS FOR DEVELOPING BREAST CANCER

Women with the following risk factors are considered high risk and may need to start having regular mammograms earlier and more frequently, and supplemental diagnostic breast ultrasound may also be ordered regularly.

• Personal history of breast or ovarian cancer.
• First-degree relative (parent, sibling, child) diagnosed with breast or ovarian cancer.
• BRCA1, BRCA2 positive.
• Three or more second-degree relatives with breast or ovarian cancer.
• Volpara D (extremely dense) breast density score.
• Chest wall radiation at an age younger than 30.
• History of lobular carcinoma in situ or atypical hyperplasia on previous breast biopsy.

Please note that having a family history of breast cancer does not mean that you WILL develop breast cancer; it simply increases your risk. Many women who develop breast cancer do not have a family history of the disease, which is why screening is important for all women, regardless of family history.

WHAT’S THE DIFFERENCE BETWEEN THE TYPES OF BREAST IMAGING?

A breast ultrasound can help determine the composition of a lump, distinguishing between a cyst, fibroglandular tissue, and a solid mass. It uses high-frequency sound waves that travel into the breast until they hit a boundary between tissues, such as fluid and soft tissue, or soft tissue and bone. At these boundaries some of the sound waves are reflected back to the probe, while others travel farther until they reach another boundary and are reflected back. Since the pitch, direction, and distance sound waves travel differ depending on the boundary they run into, a computer can interpret this information as a two-dimensional image on a screen.

Mammography is a type of X-ray exam that takes an image of the inside of the breasts – called a mammogram. It’s the best way to detect breast cancer in its early, most treatable stage, because it provides a detailed look at the internal structure of breast tissue in both men and women and can reveal changes that are too small to feel.

When used together a mammogram and breast ultrasound can help provide a comprehensive look at breast tissue.

A biopsy can be performed in cases where ultrasound or mammography cannot differentiate benign from malignant lesions. This involves the insertion of a needle into the lesion to take a small tissue sample, which is then sent to a laboratory for analysis.

Mayfair Diagnostics has 14 locations which offer mammography exams, and except for our Coventry Hills clinic, all of them use the Senographe Pristina mammography system – which helps provide a more comfortable mammogram. Visit our breast imaging page for more information.

REFERENCES

American Cancer Society (2023) “Key Statistics for Breast Cancer.” www.cancer.org. Accessed October 4, 2023.

Canadian Cancer Society (2023) “Risks for breast cancer.” www.cancer.ca. Accessed October 4, 2023.

Canadian Cancer Society (2022) “Breast cancer statistics.” www.cancer.ca. Accessed October 4, 2023.

Engmann, N.J., et al. (2017) “Population-Attributable Risk Proportion of Clinical Risk Factors for Breast Cancer.”  JAMA Oncology. 2017; 3(9) 1228-36.

Alberta Health Services (2021) “Breast Screening.” www.screeningforlife.ca. Accessed October 4, 2023.