A pelvic ultrasound is a diagnostic test that produces images of the inside of the pelvis. Pelvic ultrasounds can provide images of the uterus, cervix, vagina, fallopian tubes, and ovaries. The system is similar to radar, in that is uses sound waves at a very high frequency. When the transducer is placed on the skin, the sound waves move through the body and bounce off organs. A computer with special software converts the sound waves into images.
A pelvic ultrasound can be used to determine the size, shape, and position of the pelvic structures. It can show changes in the shape of the bladder and the blood flow thorough the pelvic organs. A form of this technique called the fetal ultrasound is used during pregnancy to monitor fetal development. A pelvic ultrasound doesn't provide an actual diagnosis, but can show abnormalities like tumors or infections.
A pelvic ultrasound may be performed by inserting the transducer on the abdomen (trans-abdominal) or through the vagina (trans-vaginal). In some cases, both may be used to obtain the best information. It is not painful, although some women report slight discomfort with a trans-vaginal ultrasound. It's important that your bladder be full for the trans-abdominal procedure, so drink plenty of water. For a trans-vaginal ultrasound, however, you should empty your bladder just before the procedure.
A pelvic ultrasound is only one of several diagnostic tests you may need. For example, you may need a pelvic examination and pap smear to look for cervical cancer. If your doctor thinks you have a vaginal infection, you may need to have a specimen collected for analysis. If you are having abnormal bleeding, your doctor might want blood tests to check your hormonal levels or the number of red blood cells (which will show if you are anemic).