A pelvic ultrasound uses sound waves to make a picture of the organs and structures in the lower belly (pelvis).
A pelvic ultrasound looks at thebladder and:
- The ovaries, uterus, cervix, andfallopian tubes of a woman (female organs).
- The prostate gland and seminal vesicles of a man (male organs).
Organs and structures that are solid and uniform (such as the uterus, ovaries, or prostate gland) or that are fluid-filled (such as the bladder) show up clearly on apelvic ultrasound. Bones may block other organs from being seen. Air-filled organs, such as the intestines, can make the image less clear.
Pelvic ultrasound can be done three ways: transabdominal, transrectal, and transvaginal.
- Transabdominal ultrasound. A small hand-held device called a transducer is passed back and forth over the lower belly. A transabdominal ultrasound is commonly done in women to look for large uterine fibroids or other problems.
- Transrectal ultrasound. The transducer is shaped to fit into the rectum. A transrectal ultrasound may be done to check for problems in men or women. It is the most common test to look at the male pelvic organs, such as the prostate and seminal vesicles. Sometimes, a small sample of tissue (biopsy) may be taken with small tools inserted through the rectum during a transrectal ultrasound.
- Transvaginal ultrasound. The transducer is shaped to fit into a woman’s vagina. A woman may have both transabdominal and transvaginal ultrasounds to look at the whole pelvic area. A transvaginal ultrasound is done to look for problems with fertility or pregnancy. In rare cases, a hysterosonogram is done to look at the inside of the uterus by filling the uterus with fluid during a transvaginal ultrasound. Sometimes, a small sample of tissue (biopsy) may be taken with small tools inserted through the vagina during a transvaginal ultrasound.
In all three types of pelvic ultrasound, the transducer sends the reflected sound waves to a computer, which makes them into a picture that is shown on a video screen. Ultrasound pictures or videos may be saved as a permanent record.
Why It Is Done
For men and women, pelvic ultrasound may be done to:
- Find the cause of blood in the urine (hematuria). An ultrasound of the kidneys may also be done.
- Find the cause of urinary problems.
- Look at the size of the bladder before and after urination. This can determine whether the bladder is emptying completely during urination.
- Check for growths in the pelvis.
- Guide the placement of a needle during a biopsy or when draining the fluid from a cyst or abscess.
- Check for colorectal cancer and how it is responding to treatment.
For women, pelvic ultrasound may be done to:
- Find out what is causing pelvic pain.
- Look for the cause of vaginal bleeding.
- Look for pelvic inflammatory disease (PID).
- Find an intrauterine device (IUD).
- Look at the size and shape of the uterus and the thickness of the uterine lining (endometrium).
- Look at the size and shape of the ovaries.
- Check the condition and size of the ovaries during treatment for infertility.
- Confirm a pregnancy and whether it is in the uterus. Pelvic ultrasound may be used early in pregnancy to check the age of the pregnancy or to find a tubal pregnancy (ectopic pregnancy) or multiple pregnancy.
- Check the cervical length in a pregnant woman at risk forpreterm labour.
- Check a lump found during a pelvic examination.
- Check uterine fibroids found during a pelvic examination. Pelvic ultrasound may also be done to check the growth of uterine fibroids.
- Guide a procedure to remove an ovarian follicle for in vitro fertilization.
For men, pelvic ultrasound may be done to:
- Look at the seminal vesicles and the prostate gland.
- Check for prostate cancer. Other tests, including digital rectal examination, prostate-specific antigen blood test, and prostate biopsy, may also be used.
- See if urinary problems are being caused by a prostate that is getting bigger, such as from benign prostatic hypertrophy (BPH).
- Check to see if a problem with the prostate gland may be causing infertility.
How To Prepare
If you are having a transabdominal ultrasound, your doctor will ask you to drink 4 to 6 glasses of juice or water about an hour before the test to fill your bladder. A full bladder pushes the intestines (which contain air) out of the way of the pelvic organs. This makes the ultrasound picture clearer. If the ultrasound is being done in an emergency situation, your bladder may be filled with water through a thin flexible tube (catheter) inserted into your bladder.
If you are having a transrectal ultrasound, you may need anenema about an hour before the test. Tell your doctor if you are allergic to latex so that a latex-free cover can be put on the transducer before it is used.
If a man is also having a biopsy of the prostate gland, he may be given antibiotics for a day before the test.
If you are having a transvaginal ultrasound, tell your doctor if you are allergic to latex so that a latex-free cover can be put on the transducer before it is used.
If both a transabdominal and transvaginal ultrasound will be done, the transabdominal ultrasound will usually be done first.
How It Is Done
This test is done by a doctor or by an ultrasound technologist (sonographer). It is done in an ultrasound room in a hospital, clinic, or doctor’s office.
You will need to remove any jewellery that might be in the way of the ultrasound. You will need to take off most of your clothes below the waist. You will be given a gown to use during the test.
You will lie on your back (or on your side) on a padded table. Gel will be put on your belly to improve the quality of the sound waves. A small, hand-held instrument called a transducer is gently moved over your belly. A picture of the organs and blood vessels can be seen on a video screen.
You need to lie very still while the ultrasound is being done. You may be asked to take a breath and hold it for several seconds during the test.
Pelvic ultrasound takes about 30 minutes. You may be asked to wait until the doctor has looked at the pictures. The doctor may want to do more pictures.
For transabdominal ultrasound, you will need to drink 4 to 6 glasses of juice or water about an hour before the test. Do not empty your bladder until the test is over. If you cannot drink enough fluid, your bladder may be filled with water through a thin flexible tube (catheter) inserted into your bladder.
When the test is done, the gel is cleaned off your skin. You can urinate as soon as the test is done.
For transrectal ultrasound, you will be asked to lie on your left side with your knees bent. A digital rectal examination will be done before the ultrasound test. Then a lubricated transducer probe will be gently inserted into your rectum. It will slowly be moved to take pictures from different angles. You may feel some pressure. Water may be put into your rectum to clean the end of the transducer so that clear pictures can be seen.
For transvaginal ultrasound, you will empty your bladder. You will be asked to lie on your back with your hips slightly raised.
A thin, lubricated transducer probe will be gently inserted into your vagina. Only the tip of the transducer is put in the vagina. You need to lie very still while the ultrasound scan is being done.
Transvaginal ultrasound may give more information than transabdominal ultrasound for women who:
- Are very overweight.
- Are being checked or treated for infertility.
- Have a hard time with a full bladder.
- Have a lot of gas in the intestines. This makes it harder for your doctor to see all the organs in the pelvis.
Transvaginal ultrasound often makes a clearer picture than transabdominal ultrasound because the transducer probe gets closer to the organs being viewed. It is often used in early pregnancy. But transvaginal ultrasound looks at a smaller area than transabdominal ultrasound.
In rare cases sterile saline is put in the uterus through a thin tube (catheter), to allow the doctor to look at the inside of the uterus (hysterosonogram).
How It Feels
If you have transabdominal ultrasound, you will likely feel pressure in your bladder and a strong urge to urinate because your bladder is full.
The gel may feel cold when it is put on your belly. You will feel light pressure from the transducer as it passes over your belly. If you have an injury or pelvic pain, the light pressure of the transducer may be painful. You will not hear or feel the sound waves.
You most likely will have a little pain during a transvaginal or transrectal ultrasound. You will feel pressure from the transducer probe as it is put into your vagina or rectum.
If a biopsy is done during the ultrasound, you may have some pain when the sample is taken.