Common questions about breast imaging

1. What is a mammogram?   

Mammography is a form of x-ray used to image the breast. Mammograms look specifically at differences in density of the breast tissue.   

2. What are different types of mammograms?   

  • Screening Mammogram: This type of mammogram is typically done to screen for breast cancer when there is not a current area of concern. This test is typically done on an annual basis for most women starting at age 40 depending on your risk factors and what your provider recommends. 

  • Diagnostic Mammogram: A diagnostic mammogram provides an additional x-ray view of the breast compared to the screening mammogram. If you have a known area of concern in the breast, or if you had a prior screening mammogram that detected an area of possible concern, then a diagnostic mammogram would be done.  Often, your provider will order diagnostic mammograms for a period of time after a surgery or treatment for breast cancer. 

  • 3D mammography, also known as tomosynthesis: Increasingly, 3D mammography is used routinely for screening and diagnostic mammography as it is becoming more widely available.  

3. What should I expect during a Mammogram 

The mammogram technologist will gently position your breast between two plates, almost like a sandwich. To fully view the breast, it is important that you are positioned correctly, and this requires pressure on the breast which can be mildly uncomfortable. Keep in mind this discomfort is very brief and most mammograms are over in about 5 minutes. 

4. My doctor says I have dense breasts. What does that mean?   

When women have very dense breast tissue, it can be more difficult for a radiologist to find abnormal lesions compared with women who do not have dense breast tissue. In this case, your oncologist might recommend additional imaging studies. It is important to know that having dense breast tissue is not abnormal. If you are known to have dense breast tissue, it may be recommended that you obtain a 3-D mammogram to be able to better see the breast tissue. Regardless of your breast density, it is very important that you keep up with regular mammograms as advised by your team.  

5. What is a breast ultrasound and what is it used for? 

A breast ultrasound is a type of imaging that takes pictures of the inside of the breasts using sound waves. Breast ultrasound may be used to look closer at an area that either feels or looks concerning in a mammogram or MRI.  Sometimes breast ultrasound is used as a supplemental screening for mammograms in women with dense breast tissue.   

6. What should I expect during this ultrasound? 

For a breast ultrasound you will be positioned on your back laying as flat as possible with the arm on the side of testing up over your head. A gel is applied to the breast and the ultrasound probe used slides over the surface of the breast and underarm region, like an ultrasound that would be done on a pregnant belly. Breast ultrasounds are not painful, but some pressure is applied which may be uncomfortable especially in women who have breast pain. 

7. What is a Breast MRI? 

Breast MRIs (Magnetic Resonance Imaging) uses radio waves and strong magnets to take very detailed pictures of the breasts.  This type of imaging is most often used to rule out any additional areas of concern in the individual who is considering a lumpectomy (surgery which will leave part of the breast intact) and may have very dense breast tissue that is not easy to see on mammogram. Breast MRIs are also used to monitor individuals who are at high risk for breast cancer, such as those with a history of breast cancer, a strong family history, have had radiation to the chest under age 30, or those with a genetic mutation.    

In some cases, patients may have large co-payments or deductibles. MRIs are an expensive test and there must be a documented need.  It is important to discuss this with your team prior to taking the test.   

8. How is the MRI experience different than the mammogram?  

If an MRI is advised, here are a few things you can expect:    

  • Prior to the procedure you will have an IV placed.  The IV will be used to administer a contrast agent called gadolineum.  Talk to your provider about gadolineum and whether you need a blood test to have your kidney function checked prior to the MRI.  Most patients over age 60 or with certain health concerns like diabetes or kidney problems may need this blood test.  As the gadolineum is excreted via your kidneys, it is important to make sure your kidney function is normal.  Most healthy people under age 60 do not need to have their kidney function checked and the protocol can vary by institution.   In most cases, gadolineum is required to screen or evaluate breast cancer.  For patients who have breast implants, MRI may be used without gadolineum to check for implant integrity.    

  • You will be positioned to lie on your stomach, with your breast coming through a hole in the table. This table will then slide in and out of the imaging tube accompanied by a loud thumping noise.  Some people find this noise bothersome.   

  • Typically, headphones and music to decrease this noise will be provided to help make you more comfortable.   

  • Breast MRI usually lasts around 30-45 minutes and will look at both breasts at the same time.   

  • Because the technology uses strong magnets, you will be asked to remove any metal including jewelry, belts or zippers.  You will be asked if you have any metal implanted in your body, such as a pacemaker or artificial joint. 

  • It is important that breast MRI is done on a high-quality MRI machine and with radiologists that have a lot of experience reading breast MRI. 

  • Although the MRI tube is often open on either end, if you have issues with claustrophobia, please make your team aware and speak with them about premedication that can help make this test more tolerable for you.    

9. What questions should I ask my doctor provider? 

  • Do I have dense breast tissue? 

  • Would you recommend that I get a breast MRI? 

  • What imaging tests should I get in the future based on my personal risk factors? 

American Cancer Society. (2022). Retrieved from Breast MRI: 

American Cancer Society. (2022, January 14). Retrieved from American Cancer Society Recommendations for Early Detection of Breast Cancer: 

Stanford Health Care. (2021). Retrieved from Our approach to Breast Imaging and Biopsy: