A pelvic ultrasound is a noninvasive diagnostic exam that produces images that are used to assess organs and structures within the female pelvis.
A pelvic ultrasound allows quick visualization of the female pelvic organs and structures including the uterus, cervix, vagina, fallopian tubes and ovaries.
Ultrasound uses a transducer that sends out ultrasound waves at a frequency too high to be heard. The ultrasound transducer is placed on the skin, and the ultrasound waves move through the body to the organs and structures within.
The sound waves bounce off the organs like an echo and return to the transducer. The transducer processes the reflected waves, which are then converted by a computer into an image of the organs or tissues being examined.
The sound waves travel at different speeds depending on the type of tissue encountered – fastest through bone tissue and slowest 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.
An ultrasound gel is placed on the transducer and the skin to allow for smooth movement of the transducer over the skin and to eliminate air between the skin and the transducer for the best sound conduction.
Another type of ultrasound is Doppler ultrasound, sometimes called a duplex study, used to show the speed and direction of blood flow in certain pelvic organs.
Unlike a standard ultrasound, some sound waves during the Doppler exam are audible.
Pelvic ultrasound may be performed using one or both of 2 methods:
Transabdominal (through the abdomen). A transducer is placed on the abdomen using the conductive gel
Transvaginal (through the vagina). A long, thin transducer is covered with the conducting gel and a plastic/latex sheath and is inserted into the vagina
The type of ultrasound procedure performed depends on the reason for the ultrasound. Only one method may be used, or both methods may be needed to provide the information needed for diagnosis or treatment.
Other related procedures that may be used to evaluate problems of the pelvis include hysteroscopy, colposcopy, and laparoscopy.
What are female pelvic organs?
The organs and structures of the female pelvis are:
Endometrium. The lining of the uterus
- Uterus (also known as the womb). The uterus is a hollow, pear-shaped organ located in a woman’s lower abdomen, between the bladder and the rectum.
It sheds its lining each month during menstruation, unless a fertilized egg (ovum) becomes implanted and pregnancy follows.
- Ovaries. Two female reproductive organs located in the pelvis in which egg cells (ova) develop and are stored and where the female sex hormones estrogen and progesterone are produced.
- Cervix. The lower, narrow part of the uterus located between the bladder and the rectum, forming a canal that opens into the vagina, which leads to the outside of the body.
- Vagina (also known as the birth canal). The passageway through which fluid passes out of the body during menstrual periods. The vagina connects the cervix and the vulva (the external genitalia).
- Vulva. The external portion of the female genital organs
What are some common uses of the procedure?
In women, a pelvic ultrasound is most often performed to evaluate the:
- fallopian tubes
Pelvic ultrasound exams are also used to monitor the health and development of an embryo or fetus during pregnancy. See the Obstetrical Ultrasound page for more information.
Ultrasound examinations can help diagnose symptoms experienced by women such as:
- pelvic pain
- abnormal bleeding
- other menstrual problems
and help identify:
- palpable masses such as ovarian cysts and uterine fibroids
- ovarian or uterine cancers
A transvaginal ultrasound is usually performed to view the endometrium, the lining of the uterus, and the ovaries.
Transvaginal ultrasound also provides a good way to evaluate the muscular walls of the uterus, called the myometrium.
Sonohysterography allows for a more in-depth investigation of the uterine cavity. Three-dimensional (3-D) ultrasound permits evaluation of the uterus and ovaries in planes that cannot be imaged directly.
These exams are typically performed to detect:
- uterine anomalies
- uterine scars
- endometrial polyps
- cancer, especially in patients with abnormal uterine bleeding
Some physicians also use 3-D ultrasound or sonohysterography for patients with infertility. Three-dimensional ultrasound provides information about the outer contour of the uterus and about uterine irregularities.
In men, a pelvic ultrasound is used to evaluate the:
- seminal vesicles
Transrectal ultrasound, a special study usually done to view the prostate gland, involves inserting a specialized ultrasound transducer into a man’s rectum.
In men and women, a pelvic ultrasound exam can help identify:
- kidney stones
- bladder tumors
- other disorders of the urinary bladder
In children, pelvic ultrasound can help evaluate:
- pelvic masses
- pelvic pain
- ambiguous genitalia and anomalies of pelvic organs
- early or delayed puberty in girls
Pelvic ultrasound is also used to guide procedures such as needle biopsies, in which needles are used to extract a sample of cells from organs for laboratory testing.
Doppler ultrasound images can help the physician to see and evaluate:
- blockages to blood flow (such as clots).
- narrowing of vessels.
- tumors and congenital vascular malformations.
How should I prepare?
You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewelry in the area to be examined.
You may be asked to wear a gown during the procedure.
Ultrasound examinations are very sensitive to motion, and an active or crying child can prolong the examination process.
To ensure a smooth experience, it often helps to explain the procedure to the child prior to the exam. Bringing books, small toys, music or games can help to distract the child and make the time pass quickly.
The ultrasound exam room may have a television. Feel free to ask for your child’s favorite channel.
What does the equipment look like?
Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a transducer that is used to do the scanning. The transducer is a small hand-held device that resembles a microphone, attached to the scanner by a cord.
The transducer sends out inaudible high frequency sound waves into the body and then listens for the returning echoes from the tissues in the body.
The principles are similar to sonar used by boats and submarines.
The ultrasound image is immediately visible on a video display screen that looks like a computer or television monitor.
The image is created based on the amplitude (loudness), frequency (pitch) and time it takes for the ultrasound signal to return from the area of the patient being examined to the transducer (the device used to examine the patient), as well as the type of body structure and composition of body tissue through which the sound travels.
A small amount of gel is put on the skin to allow the sound waves to travel back and forth from the transducer.
For ultrasound procedures requiring insertion of the transducer, such as transvaginal or transrectal exams, the device is covered with a sheath and lubricated before insertion.
How does the procedure work?
Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an object, it bounces back, or echoes.
By measuring these echo waves, it is possible to determine how far away the object is as well as the object’s size, shape and consistency (whether the object is solid or filled with fluid).
In medicine, ultrasound is used to detect changes in appearance, size or contour of organs, tissues, and vessels or detect abnormal masses, such as tumors.
In an ultrasound examination, a transducer both sends the sound waves and receives the echoing waves. When the transducer is pressed against the skin, it directs small pulses of inaudible, high-frequency sound waves into the body.
As the sound waves bounce off internal organs, fluids and tissues, the sensitive microphone in the transducer records tiny changes in the sound’s pitch and direction.
These signature waves are instantly measured and displayed by a computer, which in turn creates a real-time picture on the monitor.
One or more frames of the moving pictures are typically captured as still images. Small loops of the moving “real time” images may also be saved.
The same principles apply to ultrasound procedures such as transrectal and transvaginal which require insertion of a special transducer into the body.
Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as they move through vessels.
The movement of blood cells causes a change in pitch of the reflected sound waves (called the Doppler effect).
A computer collects and processes the sounds and creates graphs or color pictures that represent the flow of blood through the blood vessels.
Risks of the procedure
There is no radiation used and generally no discomfort from the application of the ultrasound transducer to the skin during a transabdominal ultrasound.
You may experience slight discomfort with the insertion of the transvaginal transducer into the vagina.
Transvaginal ultrasound requires covering the ultrasound transducer in a plastic or latex sheath, which may cause a reaction in patients with a latex allergy.
During a transabdominal ultrasound, you may experience discomfort from having a full bladder or lying on the examination table.
If a transabdominal ultrasound is needed quickly, a urinary catheter may be inserted to fill the bladder.
There may be risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Certain factors or conditions may interfere with the results of the test. These include, but are not limited to, the following:
- Severe obesity
- Barium within the intestines from a recent barium procedure
- Intestinal gas
- Inadequate filling of bladder (with transabdominal ultrasound). A full bladder helps move the uterus up and moves the bowel away for better imaging.
Before the procedure
Your doctor will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
Notify your doctor if you are sensitive to or are allergic to latex.
Generally, no fasting or sedation is required for a pelvic ultrasound, unless the ultrasound is part of another procedure that requires anesthesia.
Although the gel applied to the skin during the procedure does not stain clothing, you may wish to wear older clothing, as the gel may not be completely removed from your skin afterwards.
For a transabdominal ultrasound, you will be asked to drink several glasses of water or other liquid one to two hours before the procedure. Do not empty your bladder until the procedure is over.
For a transvaginal ultrasound, you should empty your bladder right before the procedure.
Based on your medical condition, your doctor may request other specific preparation.
During the procedure
A pelvic ultrasound may be performed in your doctor’s office, on an outpatient basis, or as part of your stay in a hospital. Procedures may vary depending on your condition and your hospital’s practices.
Generally, a pelvic ultrasound follows this process:
For a transabdominal ultrasound
- You will be asked to remove any clothing, jewelry, or other objects that may interfere with the scan.
- If asked to remove clothing, you will be given a gown to wear.
- You will lie on your back on an examination table.
- A gel-like substance will be applied to your abdomen.
- The transducer will be pressed against the skin and moved around over the area being studied.
- If blood flow is being assessed, you may hear a “whoosh, whoosh” sound when the Doppler probe is used.
Images of structures will be displayed on the computer screen. Images will be recorded on various media for the health care record.
Once the procedure has been completed, the gel will be removed.
You may empty your bladder when the procedure is completed.
For a transvaginal ultrasound
You will be asked to remove any clothing, jewelry, or other objects that may interfere with the scan.
If asked to remove clothing, you will be given a gown to wear.
You will lie on an examination table, with your feet and legs supported as for a pelvic examination.
A long, thin transvaginal transducer will be covered with a plastic or latex sheath and lubricated. The tip of the transducer will be inserted into your vagina. This may be slightly uncomfortable.
The transducer will be gently turned and angled to bring the areas for study into focus. You may feel mild pressure as the transducer is moved.
If blood flow is being assessed, you may hear a “whoosh, whoosh” sound when the Doppler probe is used.
Images of organs and structures will be displayed on the computer screen. Images may be recorded on various media for the health care record.
Once the procedure has been completed, the transducer will be removed.
After the procedure
There is no special type of care required after a pelvic ultrasound. You may resume your normal diet and activity unless your doctor advises you differently.
Your doctor may give you additional or alternate instructions after the procedure, depending on your particular situation.