An ultrasound exam may be used along with mammography to find out whether a lump is solid or filled with fluid (a "cyst"). This imaging technique is also used to evaluate lumps that are difficult to see on a mammogram.
In an ultrasound exam, high-frequency sound waves are bounced off tissues and internal organs to produce a picture called a sonogram. The clinician spreads a thin coating of lubricating jelly over the area to be imaged to improve conduction of the sound waves. A hand-held device, called a transducer, directs the sound waves through the skin toward specific tissues. When the sound waves are reflected back from the tissues within the breast, the patterns form a two-dimensional image of the breast on a computer.
Ultrasound is an excellent technology for differentiating fluids (such as are found in cysts) from normal breast tissue. They may not, however, show tiny calcium deposits—frequently the first indicators of a possible cancer, nor are they as good as mammograms at showing spatial resolution. For this reason, they are used to evaluate certain types of breast masses and guide needles used in a biopsy, but are not approved by the US Food and Drug Administration (FDA) as a screening tool for breast cancer.
Magnetic Resonance Imaging (MRI) is a tool used to assess abnormal areas seen on a mammogram or felt after breast surgery or radiation therapy. It may also be used several other ways: after a breast cancer diagnosis to determine the extent of the tumor; to evaluate breast implants for leaks or ruptures; to view dense breast tissue in younger women; and to detect abnormalities that can be felt, but are not visible with conventional mammography or ultrasound. The CAD system, used in conjunction with the Breast MRI technology, assists radiologists in image analysis and reporting for MRIs. In addition to a nationally recognized, fellowship-trained radiologist examining the MRI, the CAD software gives a "second read" on all patients.
During an MRI, a magnet linked to a computer creates pictures of areas inside the body. The patient lies on her stomach on a narrow table that slides into a tunnel-like enclosure in a powerful magnetic field. Without radiation, an MRI shows the structure of internal organs and soft tissue in a series of computer images that are interpreted by a radiologist.
Breast MRI is not used for routine breast cancer screening, but studies are under way to determine if it would be a valuable tool for screening certain individuals such as high-risk young women. There are some limitations to this technology. When used optimally, however, breast MRI can show subtle cancers possibly undetectable by mammography. Additionally, doctors will use breast MRI in patients with proven cancer to detect additional lesions in the same breast, find unsuspected tumors in the opposite breast, track response to chemotherapy, and look for recurrences on annual follow-up.
Breast MRI — Side view (A) and top-down view of both breasts (B) shows a mass that was not visible on the mammography demonstrating the usefulness of the breast MRI in high-risk patients. Areas of red and blue color indicate blood flow within the mass. After further evaluation, this mass was identified to be infiltrating breast cancer.
Positron Emission Mammography (PEM) is a new, advanced application of Positron Emission Tomography (PET). Whereas PET scans typically scan the whole body, PEM has been developed to scan smaller body parts to show very sharp, detailed images of abnormal tissue. Doctors can see cancers as small as 1.5 mm, the width of a grain of rice.
Cancers absorb sugar faster than healthy tissue. When a radioactive tracer in a sugar solution is injected into the patient, the cancerous tissue will absorb more of the solution. The PEM technology captures an image of the cancer.
Ductography is a special type of study that uses a contrast dye to image the breast ducts. This test (also called galactography) aids in diagnosing abnormal nipple discharge. Screening or diagnostic mammography are different from ductography because they do not use a contrast dye for their imaging.
The majority of nipple discharges are from non-cancerous causes, although all discharges should be reported to your doctor. A small hollow needle is fed into the problem duct from the nipple. A small amount of radiopaque fluid (contrast media) is then fed into the duct with a syringe and a mammogram taken of the breast. The contrast media makes the duct show up clearly on the mammogram.
Ductography is a specialized procedure and is only performed by radiologists with significant experience in performing ductography.