By Melissa Silverberg
Pelvic US is often the first imaging test performed for patients with chronic pelvic pain, infertility or other gynecologic symptoms, yet endometriosis remains notoriously difficult to detect. A new multi-center study presented on Tuesday suggests that applying the Society of Radiologists in Ultrasound (SRU) consensus criteria and performing augmented pelvic US (APU) when clinically indicated, may help radiologists identify patients who could benefit from earlier evaluation and treatment.
Endometriosis affects an estimated 10 to 15% of women worldwide, but diagnosis is frequently delayed by anywhere from four to eleven years from the onset of diagnosis.
“I’ve always been interested in women’s health and imaging, and endometriosis stood out because of its diagnostic challenges,” said Anne Y. Hu, MD, radiology resident at University of California, San Francisco. “Standard pelvic ultrasounds often don’t focus specifically on the space posterior to the uterus, which is a common place where endometriosis can be present.”
The SRU released guidelines in 2024 outlining when APU should be performed and what imaging observations radiologists should assess. APU adds targeted sweeps and cine clips to the routine exam, with an emphasis on evaluating the posterior compartment. These details matter, Dr. Hu said, because many endometriosis findings are subtle and easily overlooked.
“Augmented pelvic ultrasound is a standard ultrasound with a few additional images and cine clips to evaluate the space behind the uterus,” Dr. Hu said. “It should be performed when there is clinical concern for possible endometriosis.”
The research team retrospectively reviewed 888 patients who underwent radiology-performed transvaginal US at two academic hospitals. About one-third (32.9%) met clinical criteria for APU—far more than the researchers expected.
“I didn’t anticipate pelvic pain or endometriosis-associated symptoms making up such a significant proportion of exams,” Dr. Hu said. The study evaluated how well the SRU consensus criteria and APU classification predict which patients ultimately receive an endometriosis diagnosis.
“Ultrasound isn’t perfect, but it has utility as a screening tool for identifying patients who could have endometriosis or benefit from further workup. If ultrasound is able to detect findings suspicious for endometriosis, then it may help expedite further workup and treatment.”
Anne Y. Hu, MD
Among patients who qualified for APU, more than 30% had imaging findings that were positive or equivocal for endometriosis. Of those classified as APU-3 (positive), 76% were ultimately confirmed to have endometriosis on MRI or surgery—demonstrating strong correlation between SRU-based ultrasound findings and final diagnosis.
A total of 48 patients in the overall cohort received a new diagnosis within five years. For patients whose US did not show confirmatory findings, the mean time to diagnosis was 2.2 years.
“Ultrasound isn’t perfect, but it has utility as a screening tool for identifying patients who could have endometriosis or benefit from further workup,” Dr. Hu said. “If ultrasound is able to detect findings suspicious for endometriosis, then it may help expedite further workup and treatment.”
Clinicians should consider APU when patients present with chronic pelvic pain, cyclic abdominal pain, dysmenorrhea, infertility, dyspareunia, dyschezia, unexplained urinary symptoms, or abdominal wall masses with cyclical pain.
Earlier detection can be meaningful for patients who often feel they have been overlooked. “It can provide patients with validation that there is a potential explanation for their symptoms,” Dr. Hu said.
“Using the SRU guidelines to improve detection of endometriosis doesn’t have to be complicated,” Dr. Hu concluded. “Identifying patients with clinical risk factors and adding a few targeted ultrasound cines and images can make a significant difference.”
Access the presentation, “Assessing the Role of Society of Radiologists in Ultrasound (SRU) Consensus Criteria in Ultrasound Evaluation of Endometriosis,” (T3-SSOB02-6) on demand at RSNA.org/MeetingCentral.
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The RSNA 2025 Daily Bulletin is the official publication of the 110th Scientific Assembly and Annual Meeting of the Radiological Society of North America. Published online Sunday, November 30 — Thursday, December 4.
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