Ductogram/Galactogram: Imaging the Breast Ducts

• What is Ductography/Galactography and Why is It Performed?
• How Is Ductography Performed?
• Is Ductography Painful?
• What Treatment May Follow Ductography?
• Additional Resources and References

What is Ductography/Galactography and Why is it Performed?

Ductography (also called galactography or ductogalactography) is a special type of contrast enhanced mammography used for imaging the breast ducts. Ductography can aid in diagnosing the cause of an abnormal nipple discharge and is valuable in diagnosing intraductal papillomas and other conditions. Papillomas are wart-like, non-cancerous tumors with branchings or stalks that have grown inside the breast duct; they are the most common cause of nipple discharge.

Nipple discharge can be caused by non-cancerous tumors (such as papillomas) or cancer (such as ductal carcinoma in situ, DCIS). However, the majority of nipple discharges are due to benign (non-cancerous) causes. In particular, discharges that are yellow, green, blue, or black in color are usually categorized as less suspicious. For example, blue or black discharges are often associated with benign cysts. Discharges that are bloody, colorless, or clear in color are categorized as more suspicious, but further investigation usually results in a benign diagnosis. Bilateral nipple discharge (discharge occuring from both breasts) is usually benign and does not typically require investigation with ductography or other procedures. However, all persistent discharges should be reported to a physician for evaluation.

This ductogram (or galactogram) image shows the contrast filled breast duct as white. A small, dark round nodule may be seen in the left branch of the breast duct near the bifurcation (point where the duct splits into two branches).

Most women are able to undergo ductography. However, it may be more difficult to perform ductography in:

• Women who have severe allergies to the contrast media used during the procedure. (In some cases, it may be possible to perform ductography with premedication and non-ionic contrast since little contrast is actually absorbed during the procedure).
• Women who have had previous nipple surgery that has completely disconnected the nipple pores from the underlying ducts. (This may be a limited study but it may still be valuable in detecting abnormalities in the small segment of duct just beneath the nipple).
• Women with severe nipple retraction (turning inward) that would make the procedure difficult to perform. (However, the procedure may be worth attempting in select cases).

Screening mammography and diagnostic mammography differ from ductography in that they do not use contrast injection. Ductography is a specialized procedure and is only performed at select centers and hospitals by radiologists with significant experience with ductography. Many healthcare locations that perform screening or diagnostic mammography do not perform ductography.

How is Ductography Performed?

The ductography procedure takes between 30 minutes to an hour. Patients referred for ductography most always have nipple discharge at the time of the study. Before performing the procedure, the nipple is usually cleaned and sterilized with an alcohol swab or other material to remove any dried discharge. The radiologist then applies manual pressure to the breast to elicit a fluid discharge. In patients who experience nipple discharge, there is often a "trigger" spot that causes discharge from the nipple when pressure is applied to it. After identifying the discharging duct, the radiologist feeds a small hollow needle (called a blunt-tipped cannula) into this area of the nipple while stabilizing the nipple between his or her thumb and forefinger. Usually, no force, only downward guidance, is needed to insert the cannula into the patient’s breast duct.

Once the cannula has been gently fed down the duct, a small amount of radiopaque substance (contrast media) is injected into the breast through a syringe that is connected to the cannula. The breast is then imaged with mammography; the radiopaque contrast helps enhance the duct anatomy on the resulting images. After the procedure is completed, a bandage is typically placed over the nipple to prevent fluid or dye from staining the patient’s clothes.

The radiopaque contrast media is a pharmaceutical liquid made up of substances that weaken (attenuate) x-rays as they pass through the organ containing the contrast (in this case, the breast duct). The breast duct filled with contrast is then seen more clearly on the resulting mammogram image and allows the radiologist to better visualize intraductal papillomas or other abnormalities that may be present. The abnormality in the breast appears as a black nodule in the middle of the white duct.

If the radiologist has difficulty feeding the cannula into the breast duct, a local anesthetic gel or warm compress or washcloth is often used before re-attempting the procedure. Some physicians coat the tip of the cannula with anesthetic gel and also dab it on the surface of the nipple. If the cannula is still unable to be thread into the breast duct after three attempts, the procedure is typically canceled and rescheduled for one to two weeks later.

Is Ductography Painful?

A ductogram procedure can be mildly uncomfortable but is not usually painful. A ductogram is likely to be more uncomfortable when there is not a significant quantity of nipple discharge, making it difficult for the physician to find the opening of the discharging duct. This may require "probing" to find the right duct. If there is significant fluid discharge, the needle (cannula) insertion into the breast duct is usually much easier to perform and less uncomfortable for the patient.

The syringe is used to slowly instill the contrast material through the needle (cannula) into the breast duct. This is not painful but may cause a "full" sensation similar to when the breast fills with milk during lactation (breast-feeding). If the patient feels fullness or pain during the injection of contrast, she should tell the radiologist. The goal is to completely fill the duct with contrast to get the best image possible. A sensation of pressure or "fullness" is a good sign that the duct is full and distended (enlarged). However, care should be taken to avoid overfilling because this can hide abnormalities.

In some cases, extravasation may occur during ductography. Extravasation is the flow of contrast media from the breast duct out into the surrounding breast tissue. If extravasation occurs, the cannula is removed from the breast and the patients may be treated with a pain reliever (such as ibuprofen) if necessary. The procedure is usually rescheduled for a later date, typically one to two weeks later. To help minimize the occurrence of extravasation, ductography should be performed by radiologists with significant experience with the procedure.

What Treatment May Follow Ductography?

The ductogram (also called galactogram) may or may not identify the cause of the nipple discharge. The majority of patients who undergo ductography ultimately need surgery to treat the discharge. Surgery may involve removing a papilloma or other nodule in the breast duct. In some cases, removal of the entire ductal system may be required. For example, some patients with duct ectasia (widening and hardening of the duct) may need surgery to remove the affected duct if other treatments, such as heat compresses, do not help.

Even if the cause of discharge remains unknown after ductography, the ductogram can still help the surgeon find the affected duct so that only that duct needs to be removed. This is accomplished by mixing blue dye with the radiographic contrast so the surgeon can see the abnormal duct as blue.

Some surgeons feel that ductography is unnecessary since the patient will likely need surgery anyway. However, identifying the type of abnormality, the number of abnormalities, and their extent in the breast can be very helpful in aiding the surgeon in either removing as little tissue as necessary or in making sure to remove all of the involved tissue associated with extensive abnormalities.

Visit the page on nipple discharge to learn more about duct excision surgery.

Additional Resources and References

• Lois F. O'Grady, MD, et al., A Practical Approach to Breast Disease, Boston: Little, Brown and Company, 1995.  
• The report, "Ductography: How to and What If?," by S. Horatio Slawson, MD, and Bradley A. Johnson, MD of the Susan G. Komen Breast Center is published in Volume 21, 2001 issue of Radiographics
• To learn more about nipple discharge, please visit http://www.imaginis.com/breasthealth/nipple.asp

Updated: July 17, 2009