Ultrasound or MRI before endometriosis excision: which is best?

For most patients planning excision, neither ultrasound nor MRI is universally “best”—they answer different surgical questions. An expert transvaginal (and sometimes transrectal) ultrasound is excellent for detecting deep endometriosis, assessing organ mobility, and estimating whether the pouch of Douglas may be partially or fully obliterated, which can affect surgical complexity.

MRI often complements ultrasound by providing a broader map of multi-compartment disease and clarifying relationships to the bowel, bladder, and ureters, especially when deeper or more extensive involvement is suspected. In complex cases, we may recommend both tests so we can plan the safest approach, anticipate needed surgical support, and counsel you clearly on what to expect. If you’re deciding which study to obtain next, our team can review your symptoms and prior imaging to tailor the workup to your surgical goals.