Diagnostic mammograms are specialized mammograms designed to solve a particular problem. The radiologist designs each exam in order to answer the particular question at hand.
Reasons to have a diagnostic mammogram:
- Question arising from a screening mammogram
- Breast symptom such as a lump, focal breast pain or nipple discharge
- Follow-up exams
- Personal history of breast cancer
In addition to the four views obtained in a screening mammogram, there are many specialized views that are possible to further investigate a finding. The most common view is called a “spot compression magnification” view. This is a magnified view of a particular area of the breast. The radiologist may also want to do an ultrasound.
Ultrasound uses sound waves to generate a picture of the breast tissue. No compression is necessary. Ultrasound is particularly useful in telling cysts from solid masses in the breast. Cysts are very common and totally benign; about half of all women have some cysts in their breasts at some point. Ultrasound is also very helpful in characterizing masses and lumps.
Sometimes we do find a lesion that requires a biopsy to find out what it is. Fortunately, the vast majority of breast biopsies can be accurately performed with a needle and do not require surgery. Depending on the finding, a needle biopsy is performed, using either stereotactic (mammogram).
Why would I need a Breast Ultrasound?
Determining the Nature of a Breast Abnormality
The primary use of breast ultrasound today is to help diagnose breast abnormalities detected by a physician during a physical exam (such as a lump or bloody or spontaneous clear nipple discharge) and to characterize potential abnormalities seen on mammography.
Ultrasound imaging can help to determine if an abnormality is solid or fluid-filled or both cystic and solid. Ultrasound can also help show additional features of the abnormal area.
Doppler ultrasound is used to assess blood supply in breast lesions.
Supplemental Breast Cancer Screening
Mammography is the only screening tool for breast cancer that is known to reduce deaths due to breast cancer through early detection. Even so, mammograms do not detect all breast cancers. Some breast lesions and abnormalities are not visible or are difficult to interpret on mammograms. In breasts that are dense, meaning there is a lot of glandular tissue and less fat, many cancers can be hard to see on mammography.
Many studies have shown that ultrasound and magnetic resonance imaging (MRI) can help supplement mammography by detecting small breast cancers that may not be visible with mammography.
Ultrasound can be offered as a screening tool for women who:
- are at high risk for breast cancer and unable to tolerate an MRI examination.
- are at intermediate risk for breast cancer based on family history, personal history of breast cancer, or prior biopsy showing an abnormal result.
- have dense breasts.
- have silicone breast implants and very little tissue can be included on the mammogram.
- are pregnant or should not to be exposed to x-rays (which is necessary for a mammogram).
Ultrasound-guided Breast Biopsy
When an ultrasound examination reveals a suspicious breast abnormality, a physician may choose to perform an ultrasound-guided biopsy. Because ultrasound provides real-time images, it is often used to guide biopsy procedures.
What can I expect?
You will lie on your back with your arm raised above your head on the examining table.
A clear water-based gel is applied to the area of the body being studied to help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin. The sonographer (ultrasound technologist) or radiologist then presses the transducer firmly against the skin in various locations, sweeping over the area of interest or angling the sound beam from a farther location to better see an area of concern.
Doppler sonography is performed using the same transducer.
This ultrasound examination is usually completed within 30 minutes.
What are the benefits vs. risks?
- Most ultrasound scanning is noninvasive (no needles or injections) and is usually painless.
- Ultrasound is widely available, easy-to-use and less expensive than other imaging methods.
- Ultrasound imaging does not use any ionizing radiation.
- Ultrasound scanning gives a clear picture of soft tissues that do not show up well on x-ray images.
- Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and needle aspiration.
- Ultrasound imaging can help detect lesions in women with dense breasts.
- Ultrasound may help detect and classify a breast lesion that cannot be interpreted adequately through mammography alone.
- Using ultrasound, physicians are able to determine that many areas of clinical concern are due to normal tissue (such as fat lobules) or benign cysts. For most women 30 years of age and older, a mammogram will be used together with ultrasound. For women under age 30, ultrasound alone is often sufficient to determine whether an area of concern needs a biopsy or not.
- For standard diagnostic ultrasound there are no known harmful effects on humans.
- Interpretation of a breast ultrasound examination may lead to additional procedures such as follow-up ultrasound and/or aspiration or biopsy. Many of the areas thought to be of concern only on ultrasound turn out to be non-cancerous.
What are the limitations of Ultrasound Imaging of the Breast?
- Ultrasound is one of the tools used in breast imaging, but it does not replace annual mammography and careful clinical breast examination.
- Many cancers are not visible on ultrasound.
- Biopsy may be recommended to determine if a suspicious abnormality is cancer or not.
- Many calcifications seen on mammography cannot be seen on ultrasound. Some early breast cancers only show up as calcifications on mammography.
- Many facilities do not offer ultrasound screening, and the procedure may not be covered by some insurance plans.
- It is important to choose a facility with expertise in breast ultrasound, preferably one where the radiologists specialize in breast imaging. Ultrasound depends on the abnormality being recognized at the time of the scan as it is a "real-time" examination. This requires experience and good equipment. One measure of a facility's expertise in breast ultrasound can be found in its ACR accreditation status. Check the facilities in your area by searching the ACR-accredited facilities database.
Stereotactic-Guided Breast Biopsy. The stereotactic table is specially designed so that you can lie face-down with one breast positioned through a hole in the table. Two digital x-ray images are taken from different angles, allowing the radiologist to precisely localize the area to biopsied. Once the area has been located, the radiologist numbs the area with a local anesthetic, then uses computer guidance for precise needle placement and collection of small tissue samples.
Ultrasound-Guided Breast Biopsy. The radiologist uses ultrasound to locate the area for biopsy and to direct the needle used in collecting breast tissue samples.
Both methods are as accurate as a surgical biopsy and are performed on an outpatient basis, taking less than 40 minutes to perform and requiring no stitches. Furthermore, the patient can resume normal, non-strenuous activities immediately after the procedure is done. The samples are sent to the pathology lab for analysis. Results are usually available within 48 hours.
MRI-Guided Breast Biopsy. We can perform a standard needle biopsy in the MRI suite if a lesion is detected only on a Breast MRI exam, and this can be performed in under an hour.
Magnetic Resonance Imaging of the Breast
MRI is a technique using a very strong magnet and radio waves to pick up signals from the breast tissue. We use state-of-the-art equipment including a dedicated bilateral breast surface coil. The patient lies on the table face up to image the chest wall. This usually takes approximately 15 minutes. We then start an IV so contrast material can be administered during the next part of the exam. The primary way that abnormal tissue stands out on MRI is because it gets more blood flow than the remaining tissue. We can detect blood flow by taking images before and after infusion of the contrast (gadolinium) that is easily seen on MRI.The contrast material enhances the various structures in the breast and is an integral part of the imaging process. The patient is then placed on their stomach for approximately 20 minutes. This is the time when the contrast material is injected and the breast tissue is imaged. The entire exam takes approximately one hour. If needed a MRI-Guided Breast Biopsy may be ordered if an abnormal is seen on the Breast MRI.
Breast MRI is most useful in detecting breast cancer and evaluating the integrity of implants. Breast MRI is often employed in patients with a known breast cancer in whom there is a question about how extensive the disease is. Medical indications (reasons) for breast MRI are evolving, and are the subject of many studies around the country.
We utilize a special computer-assisted detection (CAD) program designed for the processing and interpretation of Breast MR Images.
A ductogram, also called a galactogram, is a test done if you are having persistent nipple discharge from a single duct, and your mammogram is normal. A tiny tube is inserted into the duct and a tiny amount of iodine contrast dye is injected into the duct. Several mammogram pictures are then obtained, with the ducts outlined by the iodine contrast dye. This shows whether there is anything inside the duct which could be producing the discharge. Most women report that this is not painful. When the duct is filled with fluid, it may feel a cramping sensation similar to what many women experience with their menstrual cycle.