Breast Ultrasound
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(Breast Ultrasonography, Breast Sonogram, Mammographic Ultrasound, Sonomammography,
Ultrasound Mammography)
Procedure Overview
What is breast ultrasound?
Breast ultrasound is a noninvasive (the skin is not pierced) procedure
used to assess the breasts. Ultrasound technology allows quick visualization
of the breast tissue. Ultrasound may also be used to assess blood flow
to areas inside the breasts. The examination is often used along with
mammography.
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| Illustration of the anatomy
of the female breast, front view |
Breast ultrasound uses a transducer that sends out ultrasonic sound waves
at a frequency too high to be heard. When the transducer is placed on
the breast at certain locations and angles, the ultrasonic sound waves
move through the skin and other breast tissues. The sound waves bounce
off the tissues like an echo and return to the transducer. The transducer
picks up the reflected waves, which are then converted into an electronic
picture of the breasts.
Different types of body tissues affect the speed at which sound waves
travel. Sound travels the fastest through bone tissue, and moves most
slowly through air. The speed at which the sound waves are returned to
the transducer, as well as how much of the sound wave returns, is translated
by the transducer as different types of tissue.
Prior to the procedure, clear gel is applied to the skin to allow for
smooth movement of the transducer over the skin and to eliminate air between
the skin and the transducer.
By using an additional mode of ultrasound technology during an ultrasound
procedure, blood flow within the breast can be assessed. An ultrasound
transducer capable of assessing blood flow contains a Doppler probe. The
Doppler probe within the transducer evaluates the velocity and direction
of blood flow in the vessel by making the sound waves audible. The degree
of loudness of the audible sound waves indicates the rate of blood flow
within a blood vessel. Absence or faintness of these sounds may indicate
an obstruction of blood flow.
Ultrasound may be safely used during pregnancy or in the presence of
allergies to contrast dye, because no radiation or contrast dyes are used.
New ultrasound technologies, such as three-dimensional (3D) and four-dimensional
(4D) ultrasound, tissue harmonic imaging (uses the harmonic signal generated
by tissue itself), ultrasound contrast agents, and ultrasound elastography
(low-frequency vibration technique used to evaluate movement of breast
lesions), show promise for diagnosing cancerous breast lesions in a noninvasive
manner.
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| Illustration of the anatomy
of the female breast, side view |
Related procedures that may be performed to evaluate breast problems
include mammography, breast biopsy, and breast scan. Please see these
procedures for more information.
Anatomy of the Breasts
Each breast has 15 to 20 sections, called lobes, which are arranged like
the petals of a daisy. Each lobe has many smaller lobules, which end in
dozens of tiny bulbs that can produce milk.
The lobes, lobules, and bulbs are all linked by thin tubes called ducts.
These ducts lead to the nipple in the center of a dark area of skin called
the areola. Fat fills the spaces between lobules and ducts.
There are no muscles in the breast, but muscles lie under each breast
and cover the ribs.
Each breast also contains blood vessels and vessels that carry lymph.
The lymph vessels lead to small bean-shaped organs called lymph nodes,
clusters of which are found under the arm, above the collarbone, and in
the chest, as well as in many other parts of the body.
Reasons for the Procedure
A breast ultrasound procedure is commonly performed to determine if an
abnormality detected by mammography or a palpable lump is a fluid-filled
cyst or a solid tumor (benign or malignant). Breast ultrasound may also
be used to identify masses in women whose breast tissue is too dense to
be measured accurately by mammography.
Ultrasound may be used in women for whom radiation is contraindicated,
such as pregnant women, women younger than 25 years, and women with silicone
breast implants. The procedure may also be used to guide interventional
procedures such as needle localization during breast biopsies and cyst
aspiration (removal of fluid from cyst).
There may be other reasons for your physician to recommend breast ultrasound.
Risks of the Procedure
Unlike mammography, breast ultrasound does not use radiation, and therefore
poses no risk to pregnant women.
Breast ultrasound may miss small lumps or solid tumors that are commonly
detected with mammography.
There may be other risks depending on your specific medical condition.
Be sure to discuss any concerns with your physician prior to the procedure.
Obesity and excessively large breasts may interfere with breast ultrasound.
Before the Procedure
- Your physician will explain the procedure to you and offer you the
opportunity to ask any questions that you might have about the procedure.
- If an invasive procedure such as a needle biopsy is to be done during
the breast ultrasound, you may be asked to sign a consent form that
gives permission to do the procedure. Read the form carefully and ask
questions if something is not clear.
- No fasting or sedation is required before the procedure.
- You should not apply any lotions, powder, or other substances to
the breasts on the day of the procedure.
- Dress in clothes that permit access to the area to be tested or that
are easily removed.
- Based upon your medical condition, your physician may request other
specific preparation.
During the Procedure
Breast ultrasound may be performed on an outpatient basis or as part
of your stay in a hospital. Procedures may vary depending on your condition
and your physician's practices.
Generally, breast ultrasound follows this process:
- You will be asked to remove any jewelry and clothing from the waist
up and will be given a gown to wear.
- You will be asked to lie on your back on an examination table and
raise your arm above your head on the side of the breast to be examined.
Alternatively, you may be positioned on your side.
- A conductive paste or gel will be applied to the breast(s), and a
hand-held transducer will be placed directly on the skin overlying the
breast.
- After the procedure is completed, the gel will be removed from the
breast(s).
After the Procedure
Generally, there is no special care following a breast ultrasound. However,
your physician may give you additional or alternate instructions after
the procedure, depending on your particular situation.
Online Resources
The content provided here is for informational purposes only, and was
not designed to diagnose or treat a health problem or disease, or replace
the professional medical advice you receive from your physician. Please
consult your physician with any questions or concerns you may have regarding
your condition.
This page contains links to other Web sites with information about this
procedure and related health conditions. We hope you find these sites
helpful, but please remember we do not control or endorse the information
presented on these Web sites, nor do these sites endorse the information
contained here.
American Cancer
Society
American Institute
of Ultrasound in Medicine
American Society
of Clinical Oncology
National Cancer
Institute
National Library
of Medicine
National Women’s
Health Information Center
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