Why was more endometriosis found in surgery than on imaging?

It’s very common for surgery to reveal more endometriosis than ultrasound or MRI suggested. Imaging is best viewed as a tool to estimate likelihood and to map certain higher-risk areas for surgical planning, rather than as a reliable yes/no detector for every lesion. Many endometriosis lesions are hard to see on scans because they can be small, superficial, hidden by normal anatomy, or located in areas where imaging performance varies and interpretation depends heavily on technique and experience.

Scans are also better at identifying some patterns, like ovarian endometriomas or certain deep bowel disease, than at detecting disease on ligaments, in the bladder/anterior compartment, or in complex multi-compartment cases. Imaging also can’t always capture the full extent of adhesions, scar-like tissue, or subtle inflammatory changes that may become obvious only when the pelvis is directly inspected during laparoscopy.

When we plan surgery, we consider imaging alongside your symptom history, exam findings, and overall pattern. The goal is safe, complete mapping and excision when appropriate. If your operative findings didn’t match your scan, it doesn’t mean the imaging was pointless or that your symptoms were exaggerated. It usually reflects the known limits of what scans can show. If you’re trying to make sense of your results or next steps, our team can help you review what was found, what was removed, and what else (like adenomyosis or coexisting pain drivers) may still need to be addressed.