Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Ultrasound exams do not use ionizing radiation (as used in x-rays). Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.

Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions.

A pelvic ultrasound provides pictures of the structures and organs in the lower abdomen or pelvis.

There are three types of pelvic ultrasound:

• abdominal (transabdominal)
• vaginal (transvaginal, endovaginal) for women

A Doppler ultrasound exam may be part of a pelvic ultrasound examination.

Doppler ultrasound is a special ultrasound technique that evaluates blood flow through a blood vessel, including the body's major arteries and veins in the abdomen, arms, legs and neck.

In women, a pelvic or abdominal ultrasound is most often performed to evaluate the:

• bladder.
• ovaries.
• uterus.
• cervix.
• fallopian tubes.

Pelvic ultrasound exams are also used to monitor the health and development of an embryo or fetus during pregnancy. 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 or the lining of the uterus, including its thickness, and the ovaries. Transvaginal ultrasound also affords 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. These exams are typically performed to detect:

• uterine anomalies
• uterine scars
• endometrial polyps
• fibroids
• cancer, especially in patients with abnormal uterine bleeding

Some physicians also use sonohysterography for patients with infertility. In men, a pelvic or abdominal ultrasound is used to evaluate the:

• bladder
• seminal vesicles
• prostate

In children, pelvic or abdominal ultrasound can help evaluate:

• early or delayed puberty in girls.
• pelvic pain.
• appendicitis.
• ambiguous genitalia and anomalies of the pelvic organs.
• pelvic masses in children.

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 (which may be caused by plaque).
• tumors and congenital malformation.

Transabdominal:

For most ultrasound exams, the patient is positioned lying face-up on an examination table that can be tilted or moved.

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.

Transvaginal:

Transvaginal ultrasound is performed very much like a gynecologic exam and involves the insertion of the transducer into the vagina after the patient empties her bladder. The tip of the transducer is smaller than the standard speculum used when performing a Pap test. A protective cover is placed over the transducer, lubricated with a small amount of gel, and then inserted into the vagina. Only two to three inches of the transducer end are inserted into the vagina. The images are obtained from different orientations to get the best views of the uterus and ovaries. Transvaginal ultrasound is usually performed with the patient lying on her back, possibly with her feet in stirrups similar to a gynecologic exam.

When the examination is complete, the patient may be asked to dress and wait while the ultrasound images are reviewed. However, the sonographer or radiologist is often able to review the ultrasound images in real-time as they are acquired and the patient can be released immediately.

These ultrasound examinations are usually completed within 30 minutes

Most ultrasound examinations are painless, fast and easy.

For a transabdominal exam:

After you are positioned on the examination table, the radiologist or sonographer will apply some warm water-based gel on your skin and then place the transducer firmly against your body, moving it back and forth over the area of interest until the desired images are captured. There is usually no discomfort from pressure as the transducer is pressed against the area being examined.

If scanning is performed over an area of tenderness, you may feel pressure or minor pain from the transducer.

Ultrasound exams in which the transducer is inserted into an opening of the body may produce minimal discomfort.

For a transvaginal exam:

With transvaginal ultrasound, although the examination is often performed to look for a cause of pelvic pain, the sonogram itself should not be painful or significantly increase your discomfort. A vaginal sonogram is usually more comfortable than a manual gynecologic examination.

Ultrasound waves are disrupted by air or gas; therefore ultrasound is not an ideal imaging technique for the bowel or organs obscured by the bowel. In most cases, barium exams, CT scanning, and MRI are the methods of choice in this setting.

Large patients are more difficult to image by ultrasound because tissue attenuates (weakens) the sound waves as they pass deeper into the body.