WHY MIGHT I HAVE A PELVIC ULTRASOUND EXAM?
Information obtained from a manual pelvic exam alone may be incomplete. With a pelvic sonogram, the uterus and ovaries are visualized. The sonogram may help explain findings from the manual exam or provide additional information. Common indications for a pelvic ultrasound examination include pelvic pain, abnormal vaginal bleeding, and suspicion of an abnormality on a manual gynecologic examination.
HOW IS PELVIC SONOGRAPHY PERFORMED?
There are 2 methods of performing an ultrasound examination of the pelvis: (1) abdominal or transabdominal and (2) vaginal, also called transvaginal or endovaginal. The same principles of high-frequency sound described previously apply in each technique. Abdominal or transabdominal sonography is performed by a sonographer who places a transducer on the surface of your lower abdomen. A small amount of gel is used on the skin to ensure good transducer contact. Vaginal sonography involves the insertion of a transducer into your vagina. The tip of the transducer is usually smaller than the standard speculum used when obtaining a routine Pap smear. A protective cover is placed over the transducer, which is then lubricated to ease insertion and provide better contact with your body. The transducer is inserted into your vagina by the sonographer, or you may have the option to insert it yourself in a similar manner as you would a tampon.
HOW LONG WILL THE EXAMINATION TAKE?
A typical pelvic sonogram requires fewer than 30 minutes. However, the length of time may vary greatly depending on how easily the necessary information is obtained and on the complexity of the findings.
ARE THERE ANY SPECIAL PREPARATIONS?
Abdominal scanning is usually done with you lying flat on an examination table. Garments are elevated or pulled down to expose the lower abdomen from the navel to the pubic bone. Abdominal scanning may or may not require a full bladder. A full bladder provides a “window” through which the pelvic organs may be seen. Your doctor may, therefore, ask you to drink a large quantity of water and/or refrain from urinating just prior to the examination. Preparations for vaginal scanning are similar to those for a routine manual pelvic examination. You will be asked to empty your bladder prior to the exam and to disrobe from the waist down. You will need to assume a position similar to the one used for a Pap smear with your legs placed in stirrups.
WILL I HAVE AN ABDOMINAL OR VAGINAL ULTRASOUND EXAM (OR BOTH)?
This will depend on the reason the exam has been requested. In the majority of cases, both transabdominal and transvaginal scans will be necessary. In some instances, it may be necessary to perform only a pelvic sonogram transabdominally (possibly with a full bladder). In other cases, a vaginal exam alone will be adequate. The decision as to which types of scans are necessary will be made by the ordering physician and or the sonographer performing the ultrasound.
IS ONE EXAM PREFERABLE TO THE OTHER?
Each has its advantages. The abdominal approach offers a panoramic view of the entire pelvis. This shows where one internal structure is in relation to another.
Improved visualization of some structures and detailed resolution may be achieved using the vaginal approach because the transducer is brought closer to the area being examined. Thus, this approach can be very helpful in seeing the fetal heartbeat in an early pregnancy, evaluating the internal lining of the uterus, or measuring a cyst in an ovary. The doctor or sonographer performing your ultrasound will decide whether one approach or a combination of approaches is best for your particular case.
IS VAGINAL SONOGRAPHY PAINFUL OR HARMFUL?
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 then a manual examination performed by your gynecologist or family doctor.
If you have been experiencing vaginal bleeding, whether pregnant or not, a vaginal sonogram will not be harmful and may be helpful in determining the cause of the bleeding.
Excerpt from the Medical Ultrasound Fact Sheet from the American Institute of Ultrasound in Medicine (AIUM)