What is a pelvic ultrasound?
A pelvic ultrasound is a noninvasive (the skin is not pierced) procedure 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. Doppler ultrasound may also show blood flow in certain pelvic organs.
Ultrasound uses a transducer that sends out ultrasonic sound waves at a frequency too high to be heard. When the transducer is placed at certain locations and angles, the ultrasonic sound waves move through the skin and other body tissues to the organs and structures within. The sound waves bounce off the organs 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 organs.
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.
A clear conducting gel is placed between 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.
By using an additional mode of ultrasound technology during an ultrasound procedure, blood flow 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.
Pelvic ultrasound may be performed using one or both of two 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. Please see these procedures for additional information.
Reasons for the Procedure
Pelvic ultrasound may be used for measurement and evaluation of female pelvic organs. Ultrasound assessment of the pelvis may include, but is not limited to, the following:
-size, shape, and position of the uterus and ovaries
-thickness, echogenicity (darkness or lightness of the image related to the density of the tissue), and presence of fluids or masses in the endometrium, myometrium (uterine muscle tissue), fallopian tubes, or in or near the -bladder
-length and thickness of the cervix
-changes in bladder shape
-blood flow through pelvic organs
Pelvic ultrasound can provide much information about the size, location, and structure of pelvic masses, but cannot provide a definite diagnosis of cancer or specific disease. A pelvic ultrasound may be used to diagnose and assist in the treatment of the following conditions:
-abnormalities in the anatomic structure of the uterus, including endometrial conditions
-fibroid tumors (benign growths), masses, cysts, and other types of tumors within the pelvis
-presence and position of an intrauterine contraceptive device (IUD)
-pelvic inflammatory disease (PID) and other types of inflammation or infection
-postmenopausal bleeding
-monitoring of ovarian follicle size for infertility evaluation
-aspiration of follicle fluid and eggs from ovaries for in vitro fertilization
ectopic pregnancy (pregnancy occurring outside of the uterus, usually in the fallopian tube)
-monitoring fetal development during pregnancy
-assessing certain fetal conditions
Ultrasound may also be used to assist with other procedures such as endometrial biopsy. Transvaginal ultrasound may be used with a procedure called sonohysterography in which the uterus is filled with fluid to distend it for better imaging.
There may be other reasons for your physician to recommend a pelvic ultrasound.
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/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 upon your specific medical condition. Be sure to discuss any concerns with your physician 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:
-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 physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
Notify your physician 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 upon your medical condition, your physician may request other specific preparation.
During the Procedure
A pelvic ultrasound may be performed in your physician’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 healthcare 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 healthcare 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 physician advises you differently.
Your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.