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Ultrasound techniques are radiological imaging procedures that use high-frequency sound waves to produce pictures of internal body structures or organs. These are non-invasive techniques, meaning no surgical instruments or needles pierce the body and no anesthesia is needed.
In women, the pelvic organs, mainly the reproductive organs are often affected by infections, inflammatory reactions, tumors and other abnormalities. Women’s health issues may include any of these conditions where the ovaries, fallopian tubes, the uterus, cervix, vagina and surrounding structures may be affected. If the woman is pregnant, evaluation of the fetus and the placenta may also be done.
In many cases ultrasound may be performed using the transabdominal approach, where a hand-held transducer attached to a scanner passes the abdominal surface and sends sound waves to the inside of the abdomen and pelvis . These produce images on a screen that are immediately visible to the physician, technician or radiologist. Solid organs and cystic structures, including movements and pulsations are detected. However, in overweight and obese individuals where the abdominal fat is thick, or when there is too much gas in the bowels, interference in obtaining images of the deeper pelvic organs may make visualization difficult.
When an external transabdominal ultrasound is insufficient to create accurate images, the transvaginal technique may be more helpful. This involves the insertion of the transducer that looks like a wand into the vagina as the patient is lying on her back. This is done with a lubricated instrument that is smaller than the usual speculum which is inserted during pelvic examinations. The transducer can then catch better views of the reproductive organs as it is rotated and oriented by the radiologist.
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Benefits and Risks
There are no risks or harmful effects in ultrasound techniques. The only limitation to this technique is when other tissues like fat and too much air in the bowels interfere with sound waves and prevent optimum visualization of structures. False positive results are possible, and the patient may be subjected to repeated examinations. Expertise in performing and interpreting results are needed to make the procedure accurate and useful.
The benefits are numerous, that is why transvaginal ultrasound is a technique of choice among gynecologists, obstetricians and radiologist. These advantages are:
- With regards to safety, high frequency sound waves do not affect organs or the fetus in the pelvis, and the technique does not involve ionizing radiation such as x-rays.
- It is an inexpensive, simple and non-invasive technique, does not involve surgery, injections and anesthesia. It can be done as an office procedure.
- It does not cause pain or discomfort to the patient.
- It gives clearer pictures of soft organs, cysts and tumors, providing better visualization than that of x-ray techniques. Structures that are often hidden from view are easily detected.
- It can show movements of the fetus, pulsations of blood vessels and can be used as a monitoring device during pregnancy.
- Gynecologic conditions such as ovulation, dysfunctional uterine bleeding, ectopic pregnancy and miscarriage can also be detected.
- It is helpful in guiding minimally invasive procedures as an adjunct to diagnosis, such as needle biopsies.
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To facilitate the performance of this test, the patient has to be well informed of the procedure, its benefits and what to expect during and after the examination. Allergy to latex materials must be elicited, so that the use of latex gloves and coverings may be avoided.
The patient prepares for the procedure as in a pelvic examination. She is asked to avoid taking fluids a few hours before the examination, and urinate to empty her bladder and avoid discomfort during the procedure.
Then, she is asked to undress from the waist down and is covered with a hospital gown or blanket. The patient then lies down on her back, with her feet resting on stirrups. She is asked to relax, lie still and breathe normally.
The examination usually takes only 15-30 minutes and no special after care precautions are needed. Infection is rare.
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RSNA, "Ultrasound Imaging of the Pelvis", http://www.radiologyinfo.org/en/info.cfm?PG=pelvus
Gale Encyclopedia of Medicine, "Transvaginal Ultrasound”, http://www.encyclopedia.com/topic/Transvaginal_ultrasonography.aspx