Pelvic Ultrasound

Gynaecology is the branch of medicine that deals with women’s health issues, especially the study and management of female pelvic disorders.

A pelvic or gynaecologic ultrasound is an ultrasound of the female pelvis. It examines the female pelvic organs including the uterus (commonly called the “womb”), the endometrium (the lining of the uterus), the cervix and the ovaries.

Most pelvic ultrasounds are performed using both the transabdominal and transvaginal approaches.

Transabdominal ultrasound involves scanning through your lower abdomen. Transabdominal ultrasound usually provides an overview of the pelvis rather than detailed images. The transabdominal assessment is particularly helpful for the examination of large pelvic masses extending into the abdomen, which are not always well viewed with transvaginal ultrasound.

A small amount of ultrasound gel is put on the skin of the lower abdomen, with the ultrasound probe then scanning through this gel. The gel helps improve contact between the probe and your skin.

Transvaginal ultrasound is an internal ultrasound. It involves scanning with the ultrasound probe lying in the vagina. Transvaginal ultrasound usually produces better and clearer images of the female pelvic organs, because the ultrasound probe lies closer to these structures.

The transvaginal ultrasound probe is thin, about 2cm diameter. The probe is covered with a disposable protective sheath. A small amount of ultrasound gel is placed on the end of this probe. The probe is then gently inserted a short distance into the vagina. All transvaginal probes have been cleaned and sterilised according to recommended protocols.

Your privacy will always be respected during a pelvic ultrasound, especially the transvaginal examination. You will have a towel covering your lower body, in addition to wearing a gown during the transvaginal ultrasound.

You will always have a choice about whether transvaginal ultrasound is performed. If you have concerns about transvaginal ultrasound, please discuss this with your sonographer before your pelvic ultrasound begins.

We usually get better images during transabdominal ultrasound if the bladder is partially filled, so to help your examination we ask you to drink water prior to the assessment. Please empty your bladder 1 hour before your appointment, drink 2 glasses of water and try not to empty your bladder again until after your appointment. A full bladder moves bowel out from the pelvis into the abdomen, helping visualisation of the uterus and ovaries.

Your bladder should not be so full that it causes pain. If your bladder is very full and painful, you should empty a small amount so you are more comfortable.

You will be able to empty your bladder after the transabdominal ultrasound is completed and before the transvaginal ultrasound begins.

No analgesia is required for this ultrasound. Performing the transvaginal ultrasound usually causes less discomfort than a pap smear.

A pelvic ultrasound can be performed at any time during the menstrual cycle. Your referring doctor will let you know if it is more appropriate to have your pelvic ultrasound at a particular time during your cycle. Most pelvic conditions can be adequately assessed at any time of the menstrual cycle.

The best time to have your pelvic scan is usually just after your period has finished. The timing of your scan may be more important if your doctor is concerned about an endometrial problem such as endometrial polyps (growths of the endometrium). The endometrial lining becomes thin just after the period has ceased, making polyps easier to view.

It is not always possible to make an appointment just after your period has finished, especially if you have irregular or prolonged bleeding. If the doctor is uncertain about the endometrium, it may be suggested that you have another ultrasound after your next period or have a saline sonohysterogram instead.

Not all women need to have a pelvic ultrasound.

Your doctor may find a pelvic ultrasound useful in the investigation of a number of problems including:

• Heavy or painful periods
• Pelvic pain including pain during intercourse
• Infertility
• Irregular or infrequent periods
• Postmenopausal bleeding

The pelvic ultrasound may not provide your doctor with all the answers to your problems, but it may be very helpful in diagnosis and management.

Your referring doctor will decide if further treatment or tests are needed.

The pelvic ultrasound will usually examine a number of anatomic structures:

• The uterus. Common disorders affecting the uterus include uterine fibroids (benign muscular growths) and adenomyosis (benign infiltration of the endometrium into the surrounding uterine muscle). Both these conditions are commonly associated with heavy and/or painful periods.

• The endometrium (the lining of the uterus). The endometrium changes appearance throughout the menstrual cycle. It is usually thin just after the periods have finished and before ovulation (the proliferative phase). The endometrium becomes progressively thicker and whiter on ultrasound as the menstrual cycle progresses after ovulation (the secretory phase).
  The endometrial thickness is measured and the appearances of the endometrium are noted.
  A common disorder causing abnormal vaginal bleeding is an endometrial polyp (a growth of the endometrium).
  Sometimes a saline sonohysterogram may be suggested to better view the endometrium and any suspected problems.

• The cervix. The cervix lies at the lower end of the uterus, very close to the tip of the transvaginal ultrasound probe. Problems affecting the cervix that ultrasound may detect include cervical fibroids or polyps, and advanced cervical cancer. Ultrasound will not detect precancerous changes in the cervix known as CIN – these changes require a pap smear for diagnosis.

• The ovaries. The ovaries change appearance throughout the menstrual cycle, with ovulation occurring midcycle. Follicles of varying size and number are seen within the tissue of the ovary. Follicles are a normal part of the ovary, and the structure within which eggs mature. Counting the number of follicles and measuring their size is important in fertility treatments, including IVF.
  Problems affecting the ovaries include endometriosis (a condition which may cause pelvic pain and infertility), ovarian cysts (both benign and malignant), polycystic ovaries (an appearance which may be associated with irregular periods, acne, hirsutism and altered serum hormone levels) and pelvic adhesions (scar tissue causing the ovaries to adhere to surrounding structures such as the uterus).

• The fallopian tubes. A normal fallopian tube is very thin and not usually seen on a pelvic ultrasound.
  A fallopian tube which is blocked and filled with fluid (called a hydrosalpinx) may be detected. If the patency of your fallopian tubes need to be assessed, your doctor may request a HyCoSy procedure.

• The adnexae. The adnexae are the areas on each side of the uterus, around where your ovaries are located.
  Problems in the adnexae include hydrosalpinx (blocked fallopian tubes), ectopic pregnancy (pregnancy abnormally located in the fallopian tube) and appendicitis (this is sometimes detected during a pelvic scan if the appendix lies in this area).

• The kidneys. A routine pelvic ultrasound will often briefly review your kidneys. This is done during the transabdominal ultrasound.
  Sometimes a large pelvic mass like a uterine fibroid can obstruct flow of urine from the kidney into the bladder (called hydronephrosis).

There is a diagnostic role for 3D/4D ultrasound in pelvic scans, although the conventional 2D ultrasound still provides most of the information for the doctor. A conventional 2D ultrasound of the pelvis will always be performed initially, with 3D/4D images added as needed.

At Advanced Women’s Imaging, our ultrasound probes are capable of performing both the conventional 2D ultrasound as well as 3D/4D ultrasound. You do not need a separate ultrasound to obtain 3D/4D images if these are required.

3D/4D ultrasound can obtain views of the pelvis that are not seen on the conventional 2D ultrasound, especially views of the uterus. 2D ultrasound can obtain longitudinal and transverse views of the uterus. 3D ultrasound adds in the coronal view (or C-plane) of the uterus, enabling us to get an image of the uterus that is “front on”.

3D/4D ultrasound may help in the diagnosis and assessment of pelvic conditions, including:

• Congenital uterine abnormalities. Some women are born with changes in the shape of the uterus (for example, bicornuate uterus). Minor changes in the shape of the uterus are not uncommon.
• The location of endometrial polyps.
• The location of submucous fibroids and assessment of any intramural component.
• The location of an intrauterine contraceptive device (IUCD), especially if the IUCD is abnormally located (for example, penetrating into the wall of the uterus).

Investigation of recurrent miscarriages and preterm deliveries.