Q. A friend of mine recently had a diagnostic mammogram and I had a screening one. What is the difference?

A. In terms of the initial X-ray study that is done (a mammogram), there is no difference in the images we review. The real difference between a diagnostic mammogram and a screening one is the frame of mind of the radiologist who interprets the study.

A screening mammogram is meant for a woman who is asymptomatic. In other words, she has no direct breast-related problems and simply needs her yearly check up. The radiologist does a detailed read of that mammogram, looking for signs of breast cancer. If everything is normal, the woman only needs to touch base with her primary care provider and return in one year for a routine checkup.

A diagnostic mammogram these days should be more appropriately called a diagnostic breast evaluation. It might begin with a regular mammogram involving both breasts, but it is meant for a woman who is reporting a problem. One exception would be if the woman had a recent screening mammogram and was called back to further evaluate an area of potential concern on that recent study.

However, in other cases, several scenarios could prompt a diagnostic evaluation. Maybe the patient or her doctor feels a new lump; maybe she has another problem like new onset focal breast pain, nipple discharge, or visual changes she or her doctor notice on her breast. In these cases, the radiologist needs to look at the entire mammogram as he or she would a screening mammogram – but then also needs to focus his or her attention on the problem reported by the patient.

In modern breast centers, the radiologist will then correlate the findings on the mammogram with other imaging studies and generally perform a physical exam. This is to ensure he or she fully understands the concern the patient has. For example: Is the lump the woman feels in the same area that may be changing on her mammogram? Additional mammograms and/or a sonogram, sometimes called an ultrasound examination, may be added to the evaluation. The radiologist then correlates the mammogram, the sonogram and the physical examination (and any other radiology study that might have been done) to arrive at a diagnosis for that woman.

I believe it is also important for the radiologist to then review all the studies and his or her recommendations with the patient before she leaves the center, so she understands what is going on. Fortunately, most reported breast problems turn out to be normal life changes, but sometimes not, so it is important to report any concerns you have to your doctor and get them checked out.

In summary, a screening mammogram is a quick in-and-out examination for the woman who has no specific breast problems but simply needs a routine check up. It should involve no more that 20 or 30 minutes of her day and be done once a year. A diagnostic breast evaluation is designed for a woman who needs the breast radiologist to focus on a problem and do a more detailed analysis of it, to determine if it is potentially cancerous. Sometimes this takes 30 minutes to an hour and the patient should know the results and recommendations before she leaves the center.

Michael J. Ulissey, M.D., is a partner at the Breast Diagnostic Centers of Auburn and Federal Way. He received his medical degree from Texas A&M University, College of Medicine and subsequently served as a physician in the U.S. Navy. His career since has been a mix of private practice, academic teaching and research in the fields of breast imaging, breast cancer and early detection. In addition to taking care of patients locally, he continues to participate in research as an Adjunct Professor at the University of Texas Health Sciences Center. You can reach him at Mike@breastdiagnostic.com.