Okay, so we all know that endometriosis is something we can feel (and boy, can we feel it), but did you know it’s also something that doctors can see? 

When you live with endo, your endometrial tissue grows elsewhere in the body, like the ovaries and fallopian tubes. The build-up of all this tissue outside the uterus can lead to scarring, inflammation, cysts, and even adhesions (psst, that’s where your organs fuse and are stuck to one another thanks to the excess tissue growth). 

Now while endometriosis may seem invisible on the outside, an ultrasound can give doctors the ability to identify some of the signs of endometriosis (like larger lesions and cysts) inside our bodies. 

Read on to find out exactly how we can see endometriosis on an ultrasound. 

Types of Ultrasound Used To Detect Endometriosis 

We’re all about empowering you to choose a line of diagnosis and treatment that works best for you, so if an exploratory laparoscopic surgery to confirm the presence of endo (or lack thereof) doesn’t sound like an avenue you want to go down, don’t worry – we’ve got you covered. While surgery is one of the most well-known ways that doctors can identify and diagnose endometriosis, there are other options available. 

An ultrasound is just one example of a tool that can be used to help determine the presence of endometrial tissue before you have to go under the knife. 

There are three main types of ultrasounds that experts use to detect the presence of endometriosis. These include:

  1. Transabdominal ultrasound 
  2. Transvaginal ultrasound 
  3. Transrectal ultrasound 

Transabdominal Ultrasound 

While less invasive than a transvaginal ultrasound (more on this below), a transabdominal ultrasound, AKA pelvic ultrasound, is a form of ultrasound that can be used to diagnose endometriosis. 

To put it simply, a transvaginal ultrasound is performed internally, and a transabdominal ultrasound is performed externally. 

A transabdominal ultrasound enables healthcare professionals to visualise the reproductive organs from outside of the body. Because this procedure is performed externally and doesn’t require insertion into the body, a transabdominal ultrasound is an effective alternative for individuals who may not be comfortable with an internal ultrasound.

While this method may not provide imagery that is as detailed as a transvaginal ultrasound, it is still an effective tool for detecting abnormalities and changes in the uterus, fallopian tubes, ovaries, and the endometrial tissue. 

So, can a transabdominal ultrasound offer valuable insights into the presence of endo? Yes. 

Is it as detailed and clear as a transvaginal ultrasound? No. 

In cases where a patient is experiencing symptoms that align with endometriosis (think verrry painful cramps, abdominal bloating, heavy periods and severe pelvic pain…to name a few) but the transabdominal ultrasound was unable to detect the presence of endometriosis, your healthcare professional may recommend further evaluation. 

Further evaluation may involve: 

  • Transvaginal ultrasound 
  • Pelvic examination 
  • Laparoscopy

Transvaginal Ultrasound 

A transvaginal ultrasound is a form of pelvic ultrasound that allows doctors and imaging technicians to get a closer look at female reproductive organs, such as the ovaries, uterus, cervix, and fallopian tubes. 

However, unlike the ultrasounds you might be familiar with (weird probe on top of your abdomen, cold sticky goo ringing any bells?), a transvaginal ultrasound is performed internally. The ultrasound wand is inserted into the vagina to enable the doctor to capture a close-up examination of the reproductive organs. 

The result? Images that are clearer, more detailed, and able to grant medical professionals visibility to things that an external ultrasound may typically miss.

Studies have shown that transvaginal ultrasound is an accurate, non-invasive test when used for assessing and determining the severity of pelvic endometriosis. Because of this, transvaginal ultrasound is the recommended imaging modality in the diagnosis of endo. 

What’s more, a transvaginal ultrasound isn’t just useful for confirming endometriosis. As a result of the high-resolution images they produce, they have also been used in the diagnosis of polycystic ovaries and PCOS, and to determine the presence of cysts, lesions, and fibroids

Transrectal Ultrasound

If you thought this condition couldn’t get more complex than cells similar to the lining of the uterus growing outside of the uterus, think again. Spoiler alert, there’s a reason endometriosis is considered to be a full body disease

While it’s most commonly found in the pelvis, in rare cases endo has also been found in the: 

A transrectal ultrasound explores other areas of the body where endometriosis can lay in hiding, such as the rectum, lymph nodes and bowel – the most common location of endometriosis outside of the reproductive organs

In a transrectal ultrasound, a small probe is inserted into the rectum to provide healthcare professionals with a detailed visual of both the rectum and pelvic, highlighting any adhesions or lesions that may be present. 

However, a transrectal ultrasound is not routinely used for the diagnosis of endometriosis, and is far less common than a transabdominal and transvaginal ultrasound. A transrectal ultrasound is typically reserved for specific situations where your doc may suspect deeper lesions or bowel involvement.  

How Can an Ultrasound Detect Endometriosis? 

A 2023 study conducted by the Australian Institute of Health and Welcome uncovered that the prevalence of endometriosis (aka endo) in Australian women and uterus-havers has skyrocketed from 1 in 9 to 1 in 7

With so many of us now affected by this disease, we need answers now more than ever.

Whether you opt for a transvaginal, transabdominal or rectal ultrasound, the end goal is still the same – to provide answers on whether or not endometriosis is present. 

But how does it all work? 

To strip it back to basics (or as close as we can get), an ultrasound probe emits high-frequency sound waves that create real-time images of the tissues and organs that are then fed through to a monitor for your healthcare professional to review. Think of it as an alternative method to taking a picture of your insides…without your iPhone. 

Ultrasounds also have the power to capture any cell abnormalities or irregularities, such as adhesions, cysts, lesions, and scar tissue.

What Don’t Ultrasounds Show?

Despite the high-res images, ultrasounds don’t always capture the full picture, if you’ll pardon the pun. 

Because of the limitations of ultrasound imagery, details can be missed – specifically in cases where endometriosis is found outside of the pelvis, or deep within the pelvic region, where it cannot be detected via ultrasound. 

It’s also good to remember that while ultrasounds can be helpful in identifying some signs of endometriosis, other factors and tests might be needed for a definitive diagnosis. Ultrasound is often more effective in detecting larger lesions like cysts, but may not be as helpful for smaller areas of endometriosis tissue or deep infiltrating endometriosis.

What Are the Benefits and Limitations of an Endometriosis Ultrasound?

As your partners in healthcare, our biggest mission is to empower you to feel confident and equipped to make the big decisions that impact you and your health. So with that in mind, let’s dive into some additional benefits and limitations of ultrasounds, shall we? 

Benefits of Using an Ultrasound to Diagnose Endometriosis  

  • Easily Accessible: Ultrasound machines and technicians are widely available in most clinics and hospitals. Their accessibility means that patients have the ability to access the answers and care they need, without sitting on a waitlist for 6 months.
  • Non-Invasive: An ultrasound is a preferred alternative for the initial screening and monitoring of endometriosis as it does not involve unnecessary radiation exposure, or require patients to go under the knife under the name of exploratory surgery. 
  • Immediate Results and Imaging: The provision of real-time imaging enables healthcare providers to visualise any abnormalities or areas of concerns immediately. In turn, this also streamlines the treatment process and equips your doctor with the answers to make a timely, informed diagnosis and treatment plan.

Limitations of Using an Ultrasound to Diagnose Endometriosis 

While ultrasounds do have their benefits in terms of diagnosing endometriosis, it’s important to recognise that they still have their limitations, including the ability to provide a definitive diagnosis

If you’re experiencing symptoms of endometriosis, we recommend speaking to a Women's Health specialist who can help take the guesswork out of endometriosis. Remember, the sooner you receive a diagnosis and answers, the sooner you can start receiving treatment. 

Types of Endometriosis 

To make this complex condition a little easier to diagnose and treat, doctors will group an individual’s endometriosis into the following four stages – Stages 1, 2, 3, and 4.  

Stage 1: Minimal Endometriosis 

  • Stage 1 endometriosis is classified by a few deep implants, meaning that the peritoneum (aka the lining of your abdomen) is infiltrated with endometriosis tissue. 

Stage 2: Mild Endometriosis 

  • Endometriosis that is found within the ovaries is known as Stage 2 endometriosis. This can result in lesions and ovarian cysts. 

Stage 3: Moderate Endometriosis 

  • Stage 3 endometriosis involves the organs within the pelvic cavity (think ovaries, uterus, and even the rectum). 
  • Stage 3 endometriosis also has the ability to distort the anatomy of the pelvic organs, with the tissue causing organs to stick together in some places. 

Stage 4: Severe Endometriosis 

  • Stage 4 endometriosis is the most extreme form of endometriosis, and can involve organs both within and outside of the pelvic cavity. 
  • Stage 4 endometriosis can infiltrate the bowels, heart, and lungs (to name a few).

Determining what stage of endometriosis is present is crucial for establishing a treatment plan that adequately meets your needs and addresses your symptoms. 

For more information on endo symptoms and treatments, read our article

The Wrap-Up 

Whether you suspect you may have endo, or have a confirmed diagnosis and are wanting to explore alternative treatment methods, there is no one way to approach it. If an exploratory laparoscopic surgery isn’t for you, don’t worry, you’re not alone.

Our team of dedicated women’s health experts (who not only specialise in treating endo, but also have endo themselves) will work with you to create a treatment plan that keeps you, your wishes, and your health goals in mind. And no, while surgery can be life-changing for some patients, here at Hazel we don’t believe that it’s your only option. 

While an ultrasound is just one example of one less-invasive procedure that you can undergo to assist in the diagnosis and treatment of endo, our specialists can also assist with nutrition and dietetics support, naturopathy, sexology, and referrals to more in-person services.