Pelvic / Gynaecologic Ultrasound
WHAT IS A PELVIC OR GYNAECOLOGIC 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.
HOW IS A PELVIC ULTRASOUND PERFORMED?
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.
DO I NEED A FULL BLADDER FOR THIS ULTRASOUND?
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.
DO I NEED PAIN RELIEF FOR THIS ULTRASOUND?
No analgesia is required for this ultrasound. Performing the transvaginal ultrasound usually causes less discomfort than a pap smear.
WHAT HAPPENS IF I HAVE MY PERIOD AT THE TIME OF THE APPOINTMENT?
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.
WHY WOULD I NEED A PELVIC ULTRASOUND?
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
- 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.
WHAT WILL I SEE ON MY PELVIC ULTRASOUND?
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).
WILL I HAVE 3D/4D IMAGES DURING MY PELVIC ULTRASOUND?
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.
USING ULTRASOUND FOR THE DIAGNOSIS OF ENDOMETRIOSIS
Advanced Women's Imaging is now providing targeted ultrasounds for the diagnosis of deeply infiltrating endometriosis.
What is endometriosis?
It is the presence of endometrial tissue outside the uterus. It is found most commonly on the ovaries and the pelvic peritoneum.
What is deeply infiltrating endometriosis (DIE)?
Endometriosis can also deeply infiltrate the bowel (especially the recto-sigmoid colon), uterosacral ligaments, bladder and vagina, causing implants, nodules and fibrosis.
Why is DIE important?
The diagnosis of endometriosis is often delayed, with many women suffering symptoms for years before an accurate diagnosis is made. Symptoms of DIE vary widely. A woman with DIE may be asymptomatic, or she may have symptoms including severe dysmenorrhoea and dyschezia.
DIE can be a complex condition to manage, especially if surgical intervention is necessary, being one of the most complicated surgical problems that a gynaecologist deals with.
Does physical examination help in the diagnosis of DIE?
Physical examination of the pelvis is limited in its ability to diagnose DIE and assess its severity.
How can ultrasound help in the diagnosis of DIE?
Targeted transvaginal ultrasound can now be used for the preoperative diagnosis of infiltrative disease with good rates of sensitivity and specificity.
Preoperative diagnosis of DIE helps optimise management for an individual patient. Some patients may respond with hormonal treatment; other patients may need surgical excision of endometriosis. If surgery is needed, the gynaecologist will need to consider the type of surgery, the need for bowel preparation, adequate consent of patients that may require resection of bowel nodules, and planning for the intra-operative assistance of other specialists such as colorectal surgeons.
What does a targeted DIE ultrasound involve?
A targeted DIE ultrasound is more detailed than a routine pelvic ultrasound of the uterus and ovaries. A routine pelvic ultrasound is performed first, then we specifically target areas affected by DIE. This involves assessing the peritoneum of the uterovesical pouch and the pouch of Douglas, the bowel (rectum, sigmoid colon up to 30cm from the anal verge, and free loops of bowel within the pelvis), the uterosacral ligaments, bladder, posterior vaginal fornix, and the rectovaginal septum.
The ultrasound is looking for endometriotic nodules, fibrosis and adhesions involving these structures and the surrounding tissues. This is best assessed in real time, with the ultrasound transducer gently moved back and forth, to see if structures move normally over each other.
How do patients prepare for a targeted DIE ultrasound?
Bowel preparation is not essential to the ultrasound diagnosis of DIE, but it may help in our assessment. This involves a mild laxative such as dulcolax (solution or tablet) taken orally the night before the ultrasound, in addition to a simple rectal enema (133 ml Fleet enema) approximately 1 hour prior to the ultrasound. Bowel preparation will eliminate faeces and bowel gas from the recto-sigmoid immediately prior the scan. These medications are available at minimal cost without prescription at any pharmacy.
What information will a targeted DIE ultrasound provide?
- Routine information about the uterus and ovaries, including uterine size, endometrial thickness, ovarian size and follicle number.
- The presence, size and location of endometriomas.
- The presence, size, location and depth of bowel lesions, especially recto-sigmoid. This will include an approximate distance of the lowest lesion from the anus, as lesions close to the anus will be more difficult to resect.
- The presence, size and location of lesions affecting the uterosacral ligaments, bladder, distal ureters, posterior vaginal fornix, and the rectovaginal septum.
- The presence and location of adhesions within the pelvis.
How do you optimise the initial diagnosis of endometriosis?
Be referred to Advanced Women's Imaging for a targeted endometriosis ultrasound.
How do you optimise diagnosis of the severity of endometriosis, especially DIE?
Be referred to Advanced Women's Imaging for a targeted endometriosis ultrasound.