Pelvic Ultrasound

Also Known As

Pelvic ultrasound (US) scanning, pelvic US imaging, pelvic ultrasonography or sonography.

Description

Ultrasound scans are high frequency sound waves too high for humans to hear. After the Titanic hit an iceberg and sank in 1912, many people researched ways to find underwater icebergs. During this time, SONAR (sound navigation and ranging), which uses ultrasound, was developed.

Ultrasound waves sent to the part of the body being examined are reflected, refracted, or absorbed at the interfaces inside the body. Echoes that return in this way, carry information about the size, distance, and uniformity of internal organs. This is displayed on a monitor to create an ultrasound image.


Pelvic sonography is a useful way of examining pelvic organs, such as the uterus, ovaries, fallopian tubes (uterine tubes), bladder in females; and the prostate gland, seminal vesicles, and bladder in males. During pregnancy, it is used to monitor the health and development of the fetus/embryo (unborn baby in mother's womb).

During a pelvic sonography, a hand-held device called a "transducer", is placed on the skin surface of the area being examined and is moved around. This transducer generates ultrasound and sends it through the body. It also detects the returning echoes and transmits them as electrical signals. Because one transducer continuously generates many ultrasound waves while detecting echoes, a real time image can be produced on a viewing monitor. These images can be recorded on videotape or can be frozen and recorded on to film.

Ultrasound is similar to audible sound in that it can pass through water and human organs easily, but it can't pass through air or bone. So, gel is applied to the skin to bridge the gap between the transducer and the internal organs to more effectively send the ultrasound waves.

When taking a pelvic ultrasound, drink a lot of water to fill the bladder. Normally the uterus and ovaries are behind the intestine and hard to see, but a distended bladder pushes the intestine up and the uterus back, spreading them out evenly and making the uterus and ovaries easy to see.

Advantages of this procedure

* Safe, painless, easy, fast, and widely available.
* No radiation.
* Real time imaging -- ultrasonography can be used to guide invasive procedures such as biopsy, and to visualize bowel movement and blood flow.
* In case of an emergency, bedside sonography can be done without special patient preparations.


Types of Pelvic Ultrasound

There are three types of pelvic ultrasound procedures:

1.Transabdominal (abdominal) ultrasound
While the patient is lying down, a transducer is placed on the lower stomach allowing the uterus, ovaries, and pelvic organs to be seen through a full bladder. The bladder must be full with urine, and resolution is low, but a wide picture of the entire pelvis can be seen.

2.Transvaginal (endovaginal, vaginal) ultrasound
A protective cover and lubricating gel is placed on the end of a thin, long transducer, which is inserted into the vagina to obtain US images. As the transducer by-passes the intestine and is more closely positioned to the pelvic organs, like the uterus and ovaries, better images can be obtained. There is no need to fill the bladder for this exam.

3.Transrectal (rectal) ultrasound
A protective cover and lubricating gel is placed on the end of a thin, long transducer, which is inserted into the rectum through the anus to examine the prostate gland. Because the prostate gland is right in front of the rectum, good images can be obtained through the transducer.

Doppler ultrasound can be done during each type of pelvic ultrasound procedure, which provides additional information about blood flow, helps diagnose blockages in pelvic blood vessels, and is used for examining ovarian tumors. Transvaginal ultrasound with color doppler can be used for individuals at high risk of developing ovarian cancer. Color doppler, duplex doppler and power doppler are three different techniques of doppler ultrasound.

Conditions that benefit from this procedure

* Monitoring fetal development.
* Pelvic pain.
* Pelvic mass.
* Abnormal bleeding.
* Abnormal discharge.
* Menstrual problems.
* To guide invasive procedures such as a needle biopsy and withdrawal of fluid.
* To examine blood flow and reveal blockages, including atherosclerotic plaque and blood clots, in the arteries and veins of the pelvis.


Common conditions revealed by this procedure

* Fibroids (myoma) of the uterus
* Cysts of the ovaries, uterus
* Ectopic pregnancy
* Infection
* Pelvic inflammatory diseases
* Abscess -- tubo-ovarian abscess, pelvic abscess
* Tumors, cancers of the ovaries, uterus
* Congenital anomaly
* Injury
* Stones in the bladder, urethra, lower ureters
* Lost IUD (intrauterine contraceptive device)
* Congenital anomalies, intrauterine growth retardation, death of the fetus/embryo
* Complications of pregnancy -- spontaneous abortion, missed abortion, threatened abortion, incomplete abortion
* Placental abnormality
* Hydatidiform mole
* Hyperplasia, cancer of prostate gland (in males)
* Tumor, inflammation of bladder


How this procedure is performed

You will need to remove your upper garments and put on a hospital gown. You will then be positioned on an examination table on your back with your hands above your head, and a lubricating gel will be applied to your pelvic area. An apparatus, known as a transducer, will be placed on your pelvic area and moved around to get real-time images.

If needed, a transvaginal ultrasound or transrectal ultrasound examination may be added. If so, you will be asked to urinate completely and remove all your lower garments. While lying down, a transducer will be inserted into your vagina or rectum.

After the examination, the gel will be cleaned off and you can change back into your clothes. The entire examinations usually take 10-30 minutes.

Preparation for this procedure

* Drink six glasses of water one to two hours prior to your exam, and avoid urinating. A full bladder helps with visualization of the uterus, ovaries, and bladder wall.
* Wear comfortable, loose-fitting clothing.
* Remove your upper garments before examination and put on a hospital gown.
* For transvaginal ultrasound or transrectal ultrasound examinations, you need to remove lower garments and urinate before your exam and.
* In an emergency, bedside exams can be done without special preparations.
* Tell the sonographer, sonologist, or physician sonologist conducting the examination about pain, bleeding, discharge, fever, or any other symptoms you have. Telling the examiner about past ultrasounds and surgeries is also helpful, and is sometimes crucial information.


Result of this procedure

The image recorded on film or videotape is interpreted and analyzed by a radiologist (a physician specialist experienced in ultrasound and other radiology exams). The official report is sent to the practitioner who requested the examination, who will inform you of the results and will use them as a reference in your evaluation and treatment.

Risk of this procedure

There is no known risk to humans from diagnostic ultrasound. Unlike X-ray examinations, ultrasound does not use radiation.

Limitations of this procedure

* Ultrasound does not penetrate air or bone. So if an abnormality is behind bowel gas, ribs, or calcified rib cartilage, it may not be discovered via this procedure.
* There is a limitation to ultrasound's ability to reach deep into the body. Because ultrasound is absorbed and reflected inside the body, only some of the waves reach deep places farthest from the transducer. For example, given two tumors of equal size, the tumor closest to the transducer will be discovered more readily than the more distant one. Consequently, examinations are not as productive for obese, tall patients as they are for thin or petite ones.
* Ultrasonography is an operator-dependent, subjective test. The more experienced the operator and the more closely the patient follows the operator's instructions (e.g. 'hold your breath', 'do not eat', 'repress the urge to urinate'), the better the results. Further, the more the operator knows about the patient's past medical history, current medical history, and the results of other radiological and laboratory tests, the better the examination. For best results, before taking ultrasonography, ask if the practice where the scan is being performed is accredited either by the American Institute of Ultrasound in Medicine or the American College of Radiology.
* Not all abnormalities can be discovered with a pelvic ultrasonography. For example, a PAP smear is a more sensitive test than ultrasound in detecting cervical cancer. And when diagnosed with cervical cancer, CT scans and MRI are more accurate than ultrasound in making plans for treatment.