Aug. 21, 2025
While the gold standard for diagnosis of pelvic endometriosis is surgery, gynecologic specialists and their patients have long desired a noninvasive detection method, according to Adela G. Cope, M.D., a minimally invasive gynecologic surgeon at Mayo Clinic's campus in Minnesota. Gynecologic specialists can perform a clinical diagnosis of endometriosis, but this indicates a suspected, rather than confirmed, diagnosis.
"With many conditions in OB-GYN, you can do a swab, blood test or imaging to determine a diagnosis," says Dr. Cope. "But endometriosis can be hard to detect outside of surgery."
The combination of a shortage of nonsurgical tools to identify this condition and the lack of widespread recognition of endometriosis as a legitimate diagnosis have made this disease challenging for patients and their physicians, says Dr. Cope.
"By the time patients see me in my office, they often have experienced their pain being dismissed or a perception that their pain is dismissed," she says.
The average 7- to 10-year time to diagnosis from when a patient first seeks medical attention for symptoms of this disease only adds to the burden.
Endometriosis affects 6% to 10% of individuals of reproductive age, which Dr. Cope interprets as a significant problem.
Radiological alternatives to detect endometriosis
Imaging, including MRI and ultrasound, holds potential for both diagnosis and treatment planning for pelvic endometriosis. Dr. Cope and colleagues conducted a review study to determine whether one of these radiologic modalities was superior. They published their findings in a 2024 publication in American Journal of Roentgenology. What they discovered was that overall weighted means of diagnostic statistics for ultrasound and MRI were similar with comparable specificity and sensitivity if a specialized ultrasound for endometriosis was used. She notes, however, that 100% sensitivity does not yet exist in the field of endometriosis with the diagnostic tools available currently.
The research team concluded that MRI and ultrasound can complement one another in endometriosis detection. Dr. Cope says that MRI can be a better detection tool in distal areas in the pelvis. An MRI presents a global view of the pelvic region, while ultrasound is limited by what the transducer can reach. However, specialized pelvic ultrasound can potentially help clarify involvement of deep endometriosis in some pelvic structures.
Dr. Cope notes that specialized ultrasound for the detection of endometriosis exists in some locations yet is often only available at large academic medical centers. This type of ultrasound is detailed, focused and a hands-on task for the radiologist, who requires significant training to perform it.
"Tailor your endometriosis detection to what you have available and use the modality that is best for you."
Recommendations for radiologic detection of pelvic endometriosis
In their American Journal of Roentgenology publication, Dr. Cope and colleagues say that due to the detection similarities of specialized ultrasound and MRI, expertise available in each U.S. or world region should determine which device is used.
"Tailor your endometriosis detection to what you have available, and use the modality that is best for you," says Dr. Cope. "If your facility does not have specialized ultrasound and you are suspicious of endometriosis in a patient, use MRI."
She notes that in community settings, specialized ultrasound is rare, and MRI is generally more accessible.
Beyond tailoring the choice of radiologic detection to local expertise, Dr. Cope encourages adapting the method to the presenting patient.
"Some patients can't or won't want an invasive ultrasound," she says. "For instance, they may have had trauma or pelvic floor dysfunction. Try to meet patients where they feel comfortable, be respectful and listen well to them."
Dr. Cope also cautions about the potential for false-negative radiologic results, depending on the assessment protocol used.
"A negative result doesn't necessarily mean there is no endometriosis," she says. "If you're using equipment not designed for endometriosis, it won't have the same sensitivity. If the testing is normal but you are suspicious for endometriosis, you can't say for sure the patient does not have it."
The significance of location for radiologic detection of pelvic endometriosis
The location where endometriosis screening imaging procedures are performed can make a difference in the results, says Dr. Cope. Thus, at times, repeat imaging is advisable by the new medical center if a patient is referred.
"Even if a community's gynecologic professionals do all the right things to diagnose a patient, we at Mayo Clinic have a low threshold for reimaging if there is uncertainty about the presence of endometriosis," she says. "Also, if there is any question about whether endometriosis affects other structures beyond the pelvic region, Mayo Clinic may ask patients to replicate imaging studies, even if they have just had these done in their hometowns."
Dr. Cope notes that she and colleagues are aware that redoing imaging completed recently may seem redundant and unnecessary. Yet, she indicates that surety regarding what surgical professionals will encounter in the OR and ensuring all the necessary team members are present for a patient's surgery are crucial for optimal outcomes.
At Mayo Clinic in Minnesota, multidisciplinary teams specializing in endometriosis can help patients sort through the identification and understanding of all their symptoms and their origins, she notes.
Mayo Clinic also takes on complex cases, as it offers high-volume surgeons with advanced endometriosis experience. Surgeons and other team members coordinate to provide complete care for patients, including determination of whether medical or surgical management is best for patients' disease.
A strong relationship with reproductive endocrinology colleagues also is a hallmark of Mayo Clinic's endometriosis care, benefiting patients with a history of infertility who are pursuing pregnancy and have been diagnosed with endometriosis.
Dr. Cope also notes that the Mayo Clinic endometriosis specialists see people of all gender identities, and specialists in transgender care refer patients with this disease to them.
A demonstration of Mayo Clinic's commitment to patients with endometriosis is evident in the expansion of the endometriosis practice through the addition of two surgeons specializing in this disease. This development improves access for patients who need care.
For more information
Tong A, et al. Best practices: Ultrasound versus MRI in the assessment of pelvic endometriosis. American Journal of Roentgenology. 2024;223:e2431085.
Refer a patient to Mayo Clinic.