Screening and diagnostic mammograms are both x-rays of the breasts that can help detect signs of breast cancer. Although they use the same specialized x-ray machine, the tests are very different.
Screening mammograms are routine tests done on people without signs of breast cancer. Diagnostic mammograms are more detailed scans done if a screening mammogram looks suspicious or if someone has warning signs of breast cancer.
It’s important to know the difference between screening and diagnostic mammograms to know what to expect.
What Is a Screening Mammogram?
A screening mammogram is an x-ray of the breast taken in someone who has no signs of breast cancer. They can detect indicators of breast cancer that may not be noticeable in a physical exam, including:
- Asymmetry
- Breast density
- Calcifications
- Masses
- Tissue distortions
Screening mammograms are important routine tests because they can help lead to early detection of breast cancer. You do not need a prescription for a screening mammogram.
During the exam, each breast is placed between two plates, which compress and flatten the breast tissue to get a clear image. The technologist will take two images of each breast.
Screening mammograms use a low dose of radiation — lower than typical x-rays — to create high-quality images of breast tissue.
“The benefits of screening far outweigh the risks of radiation exposure,” says Amy Kelly, MD, breast radiologist, UPMC Magee-Womens Hospital. “To put things into perspective, the dose of radiation used for a screening mammogram of both breasts is about the same amount of radiation a woman would get from natural surroundings over about seven weeks.”
A screening mammogram typically lasts 30 minutes, and you receive your results within several days.
If the images are unclear or something concerning is found, you may be called back for a diagnostic mammogram or breast ultrasound. Being called back does not necessarily mean you have breast cancer; there are many reasons why you may be called back after a screening mammogram.
What Is a Diagnostic Mammogram?
A diagnostic mammogram is a more detailed breast x-ray than a screening mammogram. You may need one if something suspicious is found during a screening mammogram. You also may need one if you have signs of breast cancer, including:
- A breast lump or mass.
- Changes in the color or texture of your skin.
- Changes in the size or shape of your breast.
- Nipple discharge.
- Nipple inversion.
You will need a prescription for a diagnostic mammogram.
The process of a diagnostic mammogram is the same as a screening mammogram. If an area of concern is found, the technologist may obtain additional views or order additional imaging tests, such as an ultrasound..
Because diagnostic mammograms take more images, the test generally lasts two to three hours. A radiologist will immediately review your results and will discuss next steps with you before you leave. It’s important to note that just because your doctor orders a diagnostic mammogram, it doesn’t mean you have breast cancer. Diagnostic mammograms help them get a more detailed look at your breast tissue.
A diagnostic mammogram is the first step leading to breast cancer diagnosis. If the mammogram indicates that you could have breast cancer, your doctor may order further tests. A biopsy may be needed to diagnose or rule out cancer.
The Key Differences Between Screening and Diagnostic Mammograms
Both screening and diagnostic mammograms are important tests, but they’re very different.
The first — and biggest — difference is the reason why you’re getting the test. Screening mammograms are routine exams for people who have no signs of breast cancer. Diagnostic mammograms are ordered for people who received concerning findings in a screening mammogram or who have symptoms of breast cancer.
Other key differences between the tests include:
- Cost — Screening mammograms are fully covered by insurance. Diagnostic mammograms may have an out-of-pocket cost, such as a copay.
- Exam length — Screening mammograms last around 30 minutes, while diagnostic mammograms take two to three hours.
- Images taken — A standard screening mammogram takes two x-ray images of each breast. A diagnostic mammogram will take several different angles and may zoom in on specific areas of concern.
- Prescription — You don’t need a prescription for a screening mammogram, but you do for a diagnostic mammogram.
- Results — You’ll receive your results from your screening mammogram within several days. Diagnostic mammogram results will be available at the end of your appointment.
Mammograms at UPMC Magee-Womens Imaging
At UPMC Magee-Womens, we believe strongly in the importance of mammograms. Both screening and diagnostic mammograms can play a crucial role in the early detection of breast cancer. Early detection can lead to earlier treatment and better outcomes.
We recommend women begin getting annual screening mammograms at 40 years old — or sooner if they are at higher risk of breast cancer. Talk to your doctor about when you should begin getting mammograms.
UPMC Magee-Womens Imaging also provides same-day screening mammograms for women who have breast pain but no other breast cancer symptoms.
For more information or to schedule your mammogram appointment, visit our website.
Editor's Note: This article was originally published on , and was last reviewed on .
Sources
American Cancer Society, Breast Cancer Mammogram. Link
BreastCancer.Org, Mammograms: How They Work & Why They Matter. Link
Breast Cancer Research Foundation, Screening vs. Diagnostic Mammogram: What Are the Differences? Link
National Breast Cancer Foundation, Inc., Mammogram. Link
National Breast Cancer Foundation, Inc., Diagnostic Mammogram. Link
National Cancer Institute, Mammograms. Link
Susan G. Komen, Mammography. Link