Positron Emission Mammography (PEM)

Positron emission mammography (PEM) can capture sharp, detailed images that pinpoint the exact size, shape and location of a breast tumor—making it a particularly useful tool for physicians as they develop treatment or surgical plans for breast cancer.

It works with an injection of a short-lived radioactive sugar into the body. The substance accumulates at the cancerous tissue in the breast and emits an energy that is detected and analyzed by special imaging technology.

In some situations, PEM offers certain advantages over the more conventional MRI exam:

  • It is a good option for a patient who has a large body habitus and cannot fit in an MRI machine, has a pacemaker or other metallic implants, or is claustrophobic.
  • It can be helpful in patients with breast implants.
  • It is less susceptible to the hormonal effects of the menstrual cycle.
  • It can help problem solve complex MRI findings.
  • Its higher sensitivity makes it an effective tool in the evaluation of DCIS (ductal carcinoma in situ), a common form of non-invasive breast cancer.

What should I expect?

About 90 minutes before the PEM scan, a nurse or technologist will check your blood sugar level to ensure it is within the acceptable range to perform the study.

A small amount of radioactive sugar will be injected into your arm. You will then sit or lie quietly in a chair or recliner while your body absorbs the radioactive sugar substance. You will be given a short hospital gown to wear during the scanning procedure.

After 90 minutes, you will be brought into the PEM scanning room and seated in a chair. The technologist will scan each breast separately, positioning each in the PEM scanner, similar to a mammogram but with less compression

A typical PEM exam requires at least two scans per breast. The entire exam, including the time prior to the actual procedure, takes two to four hours.

The radioactive sugar injected into your arm is routinely used for other medical imaging procedures without negative reactions or side effects. The radioactivity in the sugar fades quickly and leaves no detectable trace after 24 hours.

How do I prepare?

  • Do not eat or drink anything other than water and non-diabetic medication six hours before your appointment.
  • Inform your doctor and clinic staff if you are diabetic or have low blood sugar (hypoglycemia). Generally, this will not prevent you from having a PEM scan. Bring a snack with you to the appointment to eat once the nurse or technician gives you permission to do so.
  • Wear loose, comfortable clothing.

When will I receive results?

Your PEM exam will be evaluated by a radiologist, who will send a report to your physician within 24 to 48 hours after the exam. Your physician will then inform you of the results.