According to the Harvard Medical School Family Health Guide, ultrasound uses sound waves to show what is inside your body. It has several uses, including finding tumors in the pelvis, and is painless. http://www.health.harvard.edu/fhg/diagnostics/pultra/pultra.shtml
The transvaginal ultrasound (sonogram) can be used to aid in diagnosing ovarian cancer or cancer of the uterus. Since it can show an ovarian abnormality that doesn't exist, it is often used with the CA-125 blood test to diagnose ovarian cancer. It can also show the thickness of the endometrium, an aid in diagnosing endometrial cancer.
Cyndee, Pennsylvania, USA: I had this test to diagnose ovarian cancer. When I went to my doctor, I was in so much pain she could not even examine me. So she ordered a transvaginal ultrasound to help her figure out what was going on in my abdomen. Since the ovaries are so small and are generally hidden by other structures in the body, it can be difficult for a doctor to *see* them through other tests. A transvaginal ultrasound is a test that allows the ovaries and other pelvic organs to be seen in a closer view from inside the body.
When you have a transvaginal ultrasound, you are given a small probe, slightly larger than a tampon, to insert into the vagina. Part of it stays outside of the body, which allows the ultrasound technician to move and adjust the probe for a clear view of the ovaries.
I did not find this test to be uncomfortable at all. It was similar to a gynecological exam - you are on a table, covered in a lovely "stylish" gown and draped with a sheet. I was given privacy to insert the probe. I thought the test to be fairly quick, and the best part of it for me was that it is done with an empty bladder unlike some other kinds of ultrasound tests.
Sue D., Pennsylvania, USA: I had this test to help diagnose my endometrial cancer. When I had my abnormal bleeding checked, my gynecologist tried, but was not able to finish, an endometrial biopsy. Because my cervix had never been stretched by childbirth, she could not push the biopsy instrument through it without causing me severe discomfort. Instead she ordered a vaginal ultrasound to see how thick the endometrium and uterine walls were. During this test, a technician inserts a sonogram probe into the vagina and aims sound waves into the pelvic cavity where they bounce off the uterus and ovaries giving a "picture" of those organs. When the ultrasound showed that the endometrial lining was indeed thicker than it should have been, she followed-up with a D&C.