Pelvic ultrasound





Definition

Pelvic ultrasound is a procedure in which high-frequency sound waves create images of the pelvic organs. The sound waves are projected into the pelvis, and measure how they reflect—or echo—back from the different tissues.


Purpose

Ultrasound is a preferred method of examining the pelvis, and functions as an extension of a physical examination , particularly for obese patients. It is a common initial step after physical examination when a patient complains of pelvic pain or abnormal vaginal bleeding. The procedure is performed routinely during pregnancy and examinations to determine the cause of infertility. Ultrasound has the ability to detect the size and shape of pelvic organs, such as the bladder, and is useful in evaluating the cause of bladder dysfunction. In women, pelvic ultrasound is used to examine the uterus, ovaries, cervix, and vagina. In general, ultrasound can detect inflammation, free fluid, cysts (abnormal fluid-filled spaces), and tumors in the pelvic region.

A primary use of pelvic ultrasound is during pregnancy. In early pregnancy (about five to seven weeks), ultrasound may determine the size of the fetus to confirm the suspected due date, detect multiple fetuses, or confirm that the fetus is alive (viable). Ultrasound is particularly useful in distinguishing between intrauterine (within the uterus) and ectopic (outside the uterus) pregnancies. Toward the middle of the pregnancy (about 16–20 weeks), the procedure can confirm fetal growth, reveal defects in the anatomy of the fetus, and check the placenta and amniotic fluid. Toward the end of pregnancy, it may be used to evaluate fetal size, position, growth, or to check the placenta.

Doctors may use ultrasound to guide the biopsy needle during amniocentesis and chorionic villus sampling. The imaging allows precise placement of the long needle that is inserted into the patient's uterus to collect cells from the placenta or amniotic fluid.


Description

Depending on the goal of the procedure, a pelvic ultrasound can also be called a bladder ultrasound, pelvic gynecologic sonogram, or obstetric sonogram. Ultrasound examinations are usually done in a doctor's office, clinic, or hospital setting. Typically, the patient will lie on an examination table with the pelvis exposed. Special gel is applied to the area to make sure that there is no air between the hand-held transducer and the skin, and to facilitate transducer movement. The physician or technologist guides the transducer over the abdomen. The transducer both creates and receives the echoes of the high-frequency sound waves (usually in the range of 3.5–10.0 megahertz). An ultrasound scan reveals the shape and densities of organs and tissues. By performing repeated scans over time, much like the frames of a movie, ultrasound can also reveal movement, such as the motions of a fetus. This technique is called real-time ultrasound.

Using a computerized tool, called a caliper, the ultrasound technologist can measure various structures shown in the image. For example, the length of the upper thigh bone (femur) or the distance between the two sides of the skull can indicate the age of the fetus.

Ultrasound technology has been safely used in medical settings for over 30 years, and several significant extensions to the procedure have made it even more useful. A specially designed transducer probe can be placed in the vagina to provide better ultrasound images. This transvaginal or endovaginal scan is particularly useful in early pregnancy or in cases where ectopic pregnancy is suspected. It is also routinely used to provide better anatomic delineation of the endometrium and pelvic masses. In men, transrectal scans, where the probe is placed in the rectum, are done to check the prostate. Doppler ultrasound has the ability to follow the flow of blood through veins and arteries, and can be useful in detecting disorders such as abnormal blood flow associated with ovarian torsion (a twisted blood supply that causes pelvic pain). Color enhancement is particularly useful in Doppler imaging, where shades of red signify flow away from the transducer and shades of blue signify flow toward it.

Fetal ultrasound during the second to third trimester. (Brigham Narins. Reproduced by permission.)
Fetal ultrasound during the second to third trimester. (
Brigham Narins. Reproduced by permission.
)



Hysterosonography is another variant ultrasound procedure. It involves the injection of saline solution into the uterus during an endovaginal scan. The saline distends the uterine cavity (or endometrium) and simplifies the identification of polyps, fibroids, and tumors. The saline outlines the lesion, making it easier to find and evaluate. Hysterosonography can also be used in the testing of patency (openness) of the fallopian tubes during infertility evaluations.


Preparation

Before undergoing a pelvic ultrasound, the patient may be asked to drink several glasses of water and to avoid urinating for about one hour prior to exam time. When the bladder is full, it forms a convenient path, called an acoustic window, for the ultrasonic waves. A full bladder is not necessary for an endovaginal examination, sometimes making it a preferred choice in emergency situations. Women usually empty their bladders completely before an endovaginal exam.


Aftercare

For a diagnostic ultrasound, the lubricating gel applied to the abdomen is wiped off at the end of the procedure and the patient can immediately resume normal activities.

Risks

Ultrasound carries with it almost no risk for complications.


Normal results

A normal scan reveals no abnormalities in the size, shape, or density of the organs scanned. During pregnancy, a normal scan reveals a viable fetus of expected size and developmental stage. Although ultrasound is an extremely useful tool, it cannot detect all problems in the pelvic region. If a tumor or other lesion is very small or if it is masked by another structure, it may not be detected. When used during pregnancy, patients should be advised that ultrasound does not reveal all fetal abnormalities. Additionally, the reliability of ultrasound readings can depend on the skill of the technologist or physician performing the scan.

An abnormal scan may show the presence of inflammation, cysts, tumors, or abnormal blood flow patterns. These results may suggest further diagnostic procedures, or surgical or pharmacological treatment. Obstetrical ultrasound examinations may alter the anticipated due date or detect abnormalities or defects in the fetus. This information may reveal that the fetus cannot survive on its own after birth, or that it will require extensive treatment or care. The technologist performing the ultrasound should consult with a radiologist or other physician if any questionable results appear.


Resources

BOOKS

Sanders, Roger C. Clinical Sonography: A Practical Guide. Boston: Little, Brown and Company, 1998.


PERIODICALS

Galen, Barbara A. "Diagnostic Imaging: An Overview." Primary Care Practice 3 (September/October 1999).

Jorizzo, J. "Sonohysterography: The Next Step in the Evaluation of the Abnormal Endometrium." Radiographics 117 (Oct. 1999).

Kaakagi, Y. "Sonography of Obstetric and Gynecologic Emergencies: Part II, Gynecologic Emergencies." American Journal of Roetgenology 661 (Mar. 2000).

Wooldridge, Leslie. "Ultrasound Technology and Bladder Dysfunction." American Journal of Nursing Supplement 100 (June 2000).

ORGANIZATIONS

American Institute of Ultrasound in Medicine. 14750 Sweiter Lane, Suite 100, Laurel, MD 20707-5906. (301) 498-4100 or (800) 638-5352. http://www.aium.org .

American Registry of Diagnostic Medical Sonographers (ARDMS). 600 Jefferson Plaza, Suite 360, Rockville, MD 20852-1150. (301) 738-8401 or (800) 541-9754. http://www.ardms.org .

OTHER

Valley, Verna T. "Ultrasonography, Pelvic." Emedicine. January 17, 2001. [cited May 6, 2001] http://www.emedicine.com/emerg/topic622.htm .


Michelle L. Johnson, M.S., J.D. Lee A. Shratter, M.D.

User Contributions:

Amy
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Aug 29, 2006 @ 3:03 am
This is a very informative article. Thank you.
Amy Benton, Nationally Registered Certified Medical Assistant
Bonnie
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Sep 21, 2006 @ 5:05 am
Thank you for this informative, simplified article. Much appreciated.
Lily
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Nov 29, 2006 @ 9:21 pm
This is very informative, thanks this friday ill be having my ultrasound. Gives me hope that i might be pregnant cause the doctor didnt tell me if i was or not and he just sent me directly to get the pelvic ultrasound. so what does everyone think? that i am or not?
liza
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May 2, 2007 @ 9:09 am
THANKS FOR THE INFO. VERY CLEAR AND CONCISE. HOPE TOSEE MORE ABOUT YOUR TOPICS.
jeng
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Jul 25, 2007 @ 5:05 am
There are many information about many things in medicine topics......thank u very much
Yasmin
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Jan 3, 2009 @ 12:00 am
I am pregnat of 4 Months, i have had several times bleeding like the Menstrual (blood).

I feel back pain, after 1 or 2 days later, bleeding starts like the sme of menses, Not too much. But sooner, i feel like I am getting baby birthing (Painful).

I haven't had any medicin except abtibiotics,like - Amoxicillin, and Treorex Bills.
I am worried about my health and life, so dear dr. what should i do?

Thanks
yasmiin,
JHickman
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Mar 30, 2009 @ 9:21 pm
About a year ago, my gyno ordered a hysterosonogram for me after 4 days of intense cramps, the worst pain I had ever had. She ordered an abdominal ultrasound, a transvaginal ultrasound, and the hysterosonogram. She explained the hysterosonogram and it didn't sound that bad, similar to the innocuous sounding description above. Based on her explanation of the hysterosonogram, I did not expect it to be uncomfortable at all. No information I have read about this procedure mentions that a hysterosonogram can be very unpleasant. So here's how it really went: you are told to drink a lot of water for the abdominal portion of the ultrasound, then they said it was too much for the trans-vaginal portion of the test. During the trans-vaginal (INTERNAL) ultrasound, the technologist manipulated the transducer wand for so long that it irritated hemorrhoidal tissues. The radiologist said, right before he inserted the saline catheter, that it would cause cramping. There was no time then to take any type of painkiller. It was extremely uncomfortable. I really should have had a ride home but, not expecting any discomfort, had not made any prior arrangements, so had to drive home hunched over and take a prescription painkiller I had on hand when I got home. I was found to have a couple of uterine fibroids, which required no treatment at that time. Later this week I am having a "complete pelvic ultrasound", which apparently does not include a saline catheter, thank goodness. The intense cramping has returned, although not quite as bad as before. This test includes an abdominal ultrasound and a transvaginal ultrasound. The instructions from the doctor say to drink the same amount of water as before (arrive with a full bladder - 32 ozs of water), so I am skeptical if I really need that much, based on the comments from the technologist during the prior procedure. This time, I will get confirmation from the radiologist beforehand. Be aware that though you may tolerate a hysterosonogram just fine, not everyone will.
Lee
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Jul 29, 2009 @ 1:13 pm
I've been getting some stomach aches for almost 3 weeks feeling like I'm constipated but yet I'm going just fine, sometimes getting diarrhea. I went in to see a doctor and he just sent me for some blood work, urine test and a pelvic ultra sound. From your knowledge, does this sound like I could be pregnant?
Ria
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Aug 12, 2009 @ 1:01 am
This is a very helpful article!It really helped me with my pelvic sonogram.thanks a lot!
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Feb 18, 2010 @ 7:07 am
Today I'm going in for my pevlic ultrasound,Thank you very much for having this available to us.
It is very easy to read and understand and very informative. Now,I can go in with a clear picture and understanding of my procedure. THANK YOU!.
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Nov 17, 2010 @ 4:04 am
thanks very much. Appreciate the information. Demystifies upcoming appointment
renee
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Jan 14, 2011 @ 12:00 am
WHAT EXACTLY DO THE COLORS MEAN ON THE VAGINAL ULTRA SOUNDS SUCH AS COLORS OF BLUE AND SOME RED, DO THEY MEAN THERE MAY BE A PROBLEM
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Jan 20, 2011 @ 5:05 am
I find this article very educative and informative.I always bleed whenever am pregnant and later i lost those pregnancy.Am pregnant again,and i have been advised to go for a pelvic scan.I believe this one is going 2 stay.Thanks and i wish you and your team all the best.
Lisa
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Mar 13, 2011 @ 10:22 pm
I am a 42 year old female who stopped her periods June 2010. 2 separate DR's have told me I am in menopause based on Blood Tests, etc. I also went for a pelvic unltrsound and a transvaginal. 2 weeks later my daughter susoected uterine polyps and sent me for a histosonogram last Friday. On Friday I started to get bad cramps and on Saturday I statred bleeding. Today is Sunday an the cramps are worse and the bleeding has increased. What should I do?
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Jun 21, 2011 @ 3:03 am
Thanks for this article, it's quite helpful. It's give a kind of readiness and relaxation of mind to me. Regards to the team that worked on this.
veena
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Aug 10, 2011 @ 10:22 pm
I varginal ultrasound if probe does not go in side because of fear is it some problem ..will it happen with any body i am scared so i didnt fell like streching

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