Ultrasound for Endometriosis: Signs, Symptoms and Diagnostics

What is endometriosis?

Endometriosis is a gynaecological disorder affecting the female reproductive organs, and 11% of women aged 15-44 have the condition.

If you have endometriosis, tissue similar to the lining of your uterus (endometrium) grows in places it shouldn’t, such as on the ovaries, bowel, fallopian tubes, cervix and bladder. In rare cases, it can spread beyond the pelvic region.

This misplaced endometrial tissue undergoes the same hormonal changes as the tissues in the uterus do during the menstrual cycle. This means the tissues grow, thicken, and break down, which can cause inflammation and pain, as there is no way for the broken-down tissues to leave your body.

This trapped tissue can cause scarring, severe period pain, fertility problems, and adhesions (where the misplaced tissues cause pelvic organs to stick together). In some cases, a type of cyst called an endometrioma can form.

Types of Endometriosis

Endometriosis causes various symptoms, including chronic pelvic pain and heavy periods. The most severe endometriosis can spread, as endometrial tissue moves away from the womb lining. It can also move beyond the external layers of the womb lining, such as to the intestinal wall and urinary tract, causing lesions, cysts and nodules on other organs in the pelvic cavity. 

There are various different types of endometriosis, depending on how far the condition has spread and to which organs.

• Superficial Peritoneal Endometriosis - The most common form of endometriosis, also considered the least severe yet still causes sometimes extreme pelvic pain, heavy periods and potentially infertility. 

• Deep Infiltrating Endometriosis (DIE) - A severe and advanced type of deep pelvic endometriosis causing intense pain and significant changes to bowel and urinary habits. 

• Ovarian Endometriomas - A condition linked to endometriosis, that causes dark fluid-filled cysts (sometimes called chocolate cysts) on the ovaries, leading to pelvic pain and heavy periods. 

• Abdominal Wall Endometriosis - A rare form of endometriosis caused by endometrial tissue gathering at surgical sites in the abdominal wall (such as a Ceasarean section scar), causing pain and abdominal masses. 

• Diaphragmatic Endometriosis - A rare condition where endometrial tissue travels to the diaphragm (the band of thick muscle between the chest and the abdomen) causing chest pain. 

• Bowel Endometriosis - Also referred to as intestinal endometriosis, bowel endometriosis forms lesions and scarring on the intestinal walls, leading to changes in bowel habits and abdominal pain. 

• Bladder Endometriosis - Lesions and scarring form on the organs of the urinary tract, leading to pelvic pain and urinary symptoms such as pain when urinating and urinating more frequently and urgently. 

• Thoracic Endometriosis - Endometrial tissue travels to the lungs and chest cavity, causing chest and shoulder pain, breathlessness and coughing. 

• Cervical Endometriosis - Lesions and nodules form on the cervix that can cause pain during sex and abnormal vaginal bleeding. 

• Umbilical Endometriosis - Endometrial tissue travels to the belly button area (umbilicus) and causes pain and potentially discharge from the belly button. 

What are the symptoms of endometriosis?

Endometriosis has a wide range of symptoms, and diagnosing it can be difficult. Surprisingly, people with mild endometriosis might have the most severe symptoms, while people with a more extreme condition might only experience mild symptoms.

Common signs and symptoms of endometriosis include:

• Painful periods (also known as dysmenorrhea)
• Cramping similar to period pain, but at any time of the month
• Pain during or after intercourse
• Pain when using the toilet, and changes to your urine and stool
• Excessive bleeding either during your period or between periods
• Infertility and difficulty becoming pregnant. Endometriosis is one of three main causes of female infertility, but many people with endometriosis are still able to get pregnant.

What are the causes of endometriosis?

There is no known cause of endometriosis, but a combination of theories could provide some answers as to how endometriosis occurs.

The condition could be linked to genetics, as it tends to run in families, and is more common in some ethnic groups than others. It could also be linked to a problem with the immune system.

It is also believed that endometriosis could be caused by menstrual blood flowing in the wrong direction. This could cause endometrial cells to enter the fallopian tubes and the pelvic cavity, instead of being released from the body as normal (retrograde menstruation).

How is endometriosis diagnosed?

The only method for certain diagnosis of endometriosis is via a laparoscopy. This is a mildly invasive surgical procedure, where a surgeon passes a thin tube through a small cut in your abdomen. This is so that they can view endometrial tissues, and take samples of them for analysis.

Getting an endometriosis diagnosis takes time, and there are various tests and procedures that are carried out to get a full picture of what’s causing your symptoms:

1. Medical History - First, your doctor will take a full medical history from you, and will ask questions about your symptoms. 

2. Symptom Assessment - Your doctor will ask you to describe your symptoms, how frequent they are, when they occur and how much of an impact they have on your life. They may also ask if any members of your family have been affected by the same symptoms. 

3. Pelvic Examination - They will then feel around your abdomen for any palpable lumps or areas of pain. They may also perform an internal examination using a speculum inserted into the vagina. 

4. Transvaginal Ultrasound - If necessary, your doctor will refer you for a transvaginal ultrasound. During a transvaginal ultrasound, an ultrasound probe called a transducer is placed into the vagina to produce images of the uterus (womb) and the endometrium (lining of the womb) as well as the other organs within the pelvic cavity to look for signs of endometriosis. You may also have a transabdominal ultrasound where the transducer is moved over the skin of the abdomen. 

5. MRI Scan - If your endometriosis ultrasound is inconclusive, you may be referred for an MRI (magnetic resonance imaging) scan that can show up abnormalities in the pelvic cavity. 

6. Diagnostic Laparoscopy - A diagnostic laparoscopy is a keyhole surgical procedure performed under a general anaesthetic. Small, thin instruments are used, through small cuts in the abdomen and belly button, to view inside the pelvic cavity and laser away endometrial lesions and scar tissue if necessary. 

7. Biopsy During Laparoscopy - If necessary, your surgeon will also take a small sample of tissue called a biopsy, for further testing in the laboratory. 

Can you see endometriosis on an ultrasound?

While ultrasound cannot definitively diagnose endometriosis, it can allow doctors to see potential indicators, such as the presence of cysts (possible endometriomas) and misplaced endometrial tissue that has become deeply embedded in another organ. However, it is unlikely they would see small endometrial tissues, which are only on the surface of an organ, from the scan.

How does an endometriosis ultrasound work?

An ultrasound machine uses high frequency sound waves to create detailed images of the organs. During an ultrasound, a medical professional called a sonographer uses a special device called a transducer, connected to the ultrasound machine, to send sound waves into the body. The sound waves used during an ultrasound cannot be heard or felt.

When the sound waves reach the bones, soft tissues and organs, they bounce back to the transducer like an echo. Ultrasound computers turn the echoes into images that can then be used to detect abnormalities, such as the lesions and scars caused by endometriosis. 

Depending on your symptoms, the transducer used will either be transabdominal or transvaginal. During a transabdominal ultrasound, the transducer is moved over the skin of the abdomen. During a transvaginal ultrasound, the transducer is placed into the vagina to take images through the posterior vaginal wall. 

A conductor gel is used during each to act as a lubricant and to help the sound waves travel into the body and bounce back to the transducer. This gel will feel cold and wet, and is wiped away afterwards. 

An endometrium (womb lining) that’s affected by endometriosis may look different to a normal endometrium on an ultrasound, especially if deeply infiltrating endometriosis is present. An ultrasound may not be able to detect superficial endometriosis. However, a laparoscopy will be able to detect superficial disease.

💡 Find out more about the different types of ultrasounds.

What does endometriosis look like on ultrasound images?

After your scan, a radiologist will review your images, and report on their findings. They’ll be looking for potential cysts (endometriomas), abnormal tissue growth (e.g. large clumps of tissue), and other anomalies that could explain your symptoms, even if they are able to rule out endometriosis.

Once the radiologist has written a report, your consultant or GP can use the findings to decide whether you need a laparoscopy to confirm endometriosis, or to recommend treatments for any diagnosis they can confirm with your results.

Endometriosis Prognosis

Endometriosis has no cure - it’s a chronic disease, but the symptoms can be managed. During a laparoscopy, if endometriosis is seen, the lesions and scarring can be reduced with laser treatment at the same time. However, the symptoms may return as the condition can only be managed, not treated.

How is endometriosis treated?

Endometriosis is a chronic condition, and while it cannot be completely cured, there are many treatment options available. It is important to seek a diagnosis for endometriosis as early as possible, in order to help manage your symptoms.

Endometriosis also worsens with age, so if you are hoping to get pregnant, the earlier you can confirm the condition, the sooner you can begin family planning.

Medicinal treatments for endometriosis:

• Painkillers, such as ibuprofen and paracetamol, to ease symptoms.
• Hormonal contraceptives, including the combined pill, contraceptive patch, or intrauterine system (IUS) to help prevent monthly growth and build-up of endometrial tissue by regulating the menstrual cycle.
• Danazol, which is a medication to stop menstruation and reduce symptoms. It can have side effects, including acne and excessive hair growth on the face and body.

Surgical treatment options for endometriosis:

• Surgical removal of endometrial growths can be carried out without damaging the reproductive organs. This is for people who want to get pregnant or do not experience relief from hormone treatments.
• A total hysterectomy (surgery to remove the uterus, cervix and ovaries) is offered as a last resort if no other treatments are successful. Having a hysterectomy means you won't be able to have children, and while it is an option, it is not commonly offered as an endometriosis treatment.

Find an Ultrasound Scan for Endometriosis

Getting an endometriosis diagnosis can be difficult, as it requires a surgical procedure to definitively diagnose. But having an ultrasound scan is your first step towards a diagnosis and managing your symptoms. Jump the waiting lists and book a private endometriosis ultrasound today.

💡 Next steps:

• • Book a private ultrasound scan to assess endometriosis symptoms, with a quick referral and fast results from our clinical team

FAQs

What Does Endometriosis Look Like on Ultrasound?

Depending on the level of disease, endometriosis can appear in various ways on an ultrasound scan. 

For example, deep pelvic endometriosis that infiltrates both the anterior and posterior compartments of the pelvic cavity will appear as dark nodules, known as hypoechoic nodules, or solid masses with irregular margins. (The anterior compartment includes the urinary tract organs such as the bladder, and the posterior compartment includes the lower parts of the digestive tract.)

Such deep endometriosis will also show as a thickening of the surrounding tissues such as the area between the vagina and the rectum, called the rectovaginal septum. It can also affect the fibrous round ligament cords that support the womb in the pelvic cavity. 

Superficial endometriosis may not show on an ultrasound at all, but that’s not to say that it isn’t present, just that it's not detectable on ultrasound. A laparoscopy is therefore necessary to diagnose the condition. 

Can Endometriosis Be Missed on Ultrasound?

Yes, superficial endometriosis may be missed on an ultrasound scan. If you’re experiencing the symptoms of endometriosis but an ultrasound scan was inconclusive, your doctor will discuss a surgical laparoscopy procedure with you. 

Sources used:

https://www.hopkinsmedicine.org/health/conditions-and-diseases/endometriosis

https://www.healthline.com/health/endometriosis#treatment

https://www.womenshealth.gov/a-z-topics/endometriosis

https://www.medicalnewstoday.com/articles/149109#symptoms

https://www.mayoclinic.org/diseases-conditions/endometriosis/symptoms-causes/syc-20354656

https://www.endometriosis-uk.org/understanding-endometriosis

https://www.nhs.uk/conditions/endometriosis/

https://my.clevelandclinic.org/health/diagnostics/21814-endometriosis-ultrasound