For many years, diagnosing endometriosis often required surgery. However, the RANZCOG 2025 Australian Living Evidence Guideline: Endometriosis, released in May 2025, reflects a major shift in approach.

The updated guideline recognises that invasive surgery is no longer necessary in every case to confirm endometriosis. Instead, expert imaging, like ultrasound and MRI, is recommended as a first-line investigation when symptoms suggest the condition.

This change means:

• Earlier diagnosis
• Fewer unnecessary surgical procedures
• More personalised treatment planning
• Better coordination of care

Imaging does not simply “look for” endometriosis, it helps map the disease and guide decisions.

Transvaginal ultrasound is usually the first imaging test performed. When carried out by experienced sonographers using dedicated endometriosis protocols, ultrasound can detect:

• Ovarian endometriomas (“chocolate cysts”)
• Deep infiltrating endometriosis
• Disease involving the bowel or bladder
• Signs of adhesions (internal scar tissue)
• Reduced organ mobility

In many cases, ultrasound findings are enough to support starting medical treatment or determining whether referral to a specialist surgeon is appropriate.

MRI provides highly detailed cross-sectional images of the pelvis and is particularly helpful when:

• Ultrasound findings are inconclusive or transvaginal scan is inappropriate
• Deep Endometriosis is suspected on ultrasound
• It is suspected that the endometriosis may be affecting the bowel, bladder or ureter and surgery is being planned

MRI offers a detailed anatomical “roadmap,” showing the depth of disease and its relationship to surrounding organs. This is especially important in complex cases, where multidisciplinary surgical planning may be required.

Imaging plays a central role in decision-making. It helps determine whether:

• Hormonal therapy and medical management are appropriate
• Surgery is necessary
• Additional specialists (such as colorectal or urology surgeons) should be involved
• Fertility planning needs consideration

Accurate pre-operative mapping reduces unexpected findings at surgery and helps patients better understand what treatment may involve.

Imaging can also be used to monitor response to therapy or reassess symptoms over time.

The 2025 RANZCOG guideline emphasises the importance of recognising endometriosis in adolescents. Severe period pain that does not respond to first-line treatments should not be dismissed as “normal.”

In younger patients:

• Imaging findings may be subtle
• Early disease may not always be visible
• Symptoms may not correlate directly with scan findings

A normal scan does not automatically exclude endometriosis. Specialist interpretation by radiologists experienced in women’s imaging is particularly important in this age group to ensure symptoms are appropriately assessed and managed.

The accuracy of endometriosis imaging depends on both technique and interpretation. Dedicated scanning protocols and specialist radiologist reporting ensure that:

• Disease is carefully mapped
• Depth and organ involvement are clearly described
• Findings are communicated effectively to the treating clinician

Imaging results are most powerful when considered alongside a patient’s symptoms and clinical history.

The 2025 Australian Living Evidence Guideline confirms that high-quality ultrasound and MRI are now central to modern endometriosis care. By shifting toward non-invasive diagnosis and detailed imaging assessment, patients benefit from earlier answers, clearer treatment pathways, and more coordinated multidisciplinary care.

At I-MED Australia, specialist imaging plays a key role in supporting clinicians and patients through every stage of endometriosis management — from initial suspicion to treatment planning and ongoing care