A practical radiology guide to the 2025 ESUR consensus on MRI preparation, essential sequences, endometriosis lexicon, compartment-based mapping, and structured reporting.
Browse the other checklists, phrase sets, and systematic approaches in this topic.
The 2025 European Society of Urogenital Radiology (ESUR) consensus updates the society's earlier guidance on pelvic MRI for endometriosis. Its central message is practical: a technically adequate examination, standardized terminology, and systematic compartment-based mapping are all necessary if MRI is to support multidisciplinary decision-making and surgical planning.
The update provides a practical framework for MRI protocol design, standardized terminology, compartment-based analysis, and structured reporting.
Clinical scope This article is an educational summary for radiology professionals. It does not replace the full consensus documents, local protocols, multidisciplinary discussion, or patient-specific clinical judgment.
The consensus addresses four recurring sources of variation in endometriosis MRI:
The most consequential reporting change is the recommendation to evaluate deep endometriosis using a compartment-based map, rather than describing lesions as an unstructured list. This creates a repeatable search pattern and helps the radiologist communicate disease extent in surgically relevant terms.
| Preparation item | ESUR recommendation | Practical note |
|---|---|---|
| Menstrual-cycle timing | No specific timing is required | Do not delay an otherwise indicated examination solely to match a cycle phase. |
| Fasting | Recommended | Follow local safety and medication policies. |
| Antiperistaltic agent | Recommended | When used, administer close to the most informative T2-weighted acquisitions. |
| Bladder filling | Moderate filling is highly recommended | The consensus suggests voiding 30–60 minutes before the examination after drinking water. |
| Bowel preparation | Highly recommended | Options vary by institution and may include an enema, suppository, evacuation, laxative, or low-residue regimen. |
| Vaginal opacification | Optional | May be useful in selected cases; it is not recommended as a routine requirement. |
| Rectal opacification | Optional | Use selectively because luminal material may obscure adjacent lesions. |
| Patient position | Supine | Phased-array coils are recommended at both 1.5 T and 3 T. |
A core examination should include:
The kidney-containing sequence is important because ureteric disease can cause upstream dilatation that may be missed on a pelvis-only field of view.
Consider the following according to the clinical question and findings:
Routine diaphragmatic assessment did not reach consensus; suspected thoracic or diaphragmatic disease may require a dedicated protocol.
Superficial endometriosis may appear as small high-signal foci on fat-suppressed T1-weighted images along a peritoneal surface.
Typical locations include:
The consensus permits the term micro-endometrioma for an intraovarian, high-signal focus on fat-suppressed T1-weighted imaging measuring 1 cm or less.
Report:
Use endometrioma for a cyst larger than 1 cm with endometriotic content and no solid tissue.
Typical MRI features include:
Report:
A suspected solid component requires careful distinction from clot. When morphology is indeterminate, absence of enhancement supports clot, whereas enhancing solid tissue requires a complete adnexal mass characterization protocol.
Consider:
Enhancing solid tissue within an endometrioma raises concern for malignant or borderline transformation, including clear cell and endometrioid malignancy. The imaging finding is not itself a histologic diagnosis, but it should alter the level of concern and subsequent assessment.
Endometriotic hematosalpinx is suggested by a dilated tubular adnexal structure containing material with high T1-weighted signal and intermediate or low T2-weighted signal.
Report:
Internal adenomyosis is associated with endometriosis but should be distinguished from external adenomyosis, which represents outside-in infiltration of the outer myometrium by deep endometriosis.
Other descriptors—such as symmetric versus asymmetric, superficial versus deep, or active versus inactive—may be useful, but did not all reach the same level of consensus.
The consensus recommends dividing the pelvis into central and bilateral lateral regions. In practical reporting language, this can be organized as:
These are reporting regions rather than true fascial anatomic spaces. Their purpose is to create a reproducible search pattern and communicate disease extent clearly.
Bladder endometriosis is suspected when a T2-hypointense nodule or mass involves the muscular layer, often forming an obtuse angle with the bladder wall and sometimes protruding toward the lumen.
Specify the location:
Report:
Laterolateral and craniocaudal measurements may be added when useful.
Suspect involvement when the proximal round ligament is asymmetrically thickened, fibrotic, irregular, or nodular compared with the opposite side.
Report:
Thickness alone is not sufficiently specific; interpret it with morphology and signal features.
A uterosacral ligament measuring 3 mm or less may be considered normal. Thickness by itself, however, is not sufficiently specific for endometriosis.
Consider a uterosacral ligament abnormal when:
A finding visible in only one plane should be treated as uncertain rather than definitively positive.
Report:
Typical findings include T2-hypointense thickening or a nodule involving the posterior wall or fornix.
Report:
Assess for partial or complete obliteration of the rectouterine space.
Report:
Use the term rectovaginal septum only for subperitoneal or retroperitoneal lesions located below the peritoneal reflection of the pouch of Douglas.
Report:
This terminology should not be used indiscriminately for every lesion between the uterus, vagina, and rectum.
External adenomyosis appears as ill-defined, T2-hypointense, outside-in infiltration of the outer myometrium.
Report:
Rectal or rectosigmoid disease typically appears as focal T2-hypointense thickening or a mass involving the anterior bowel wall.
The classic mushroom cap sign consists of a low-signal fibromuscular base capped by relatively high-signal edematous submucosa or mucosa displaced toward the bowel lumen.
Submucosal or mucosal edema may be described when it is helpful, but it is not a substitute for the surgically relevant measurements above.
Each lateral compartment can be considered in three parts.
Assess for asymmetric fibrotic thickening, irregularity, or a focal nodule extending toward the deep inguinal ring or inguinal canal.
Report:
The mediolateral parametrium contains the ureter, vessels including the uterine artery, and the inferior hypogastric plexus.
Report:
Report:
Report:
This region contains a substantial portion of the hypogastric plexus; precise mapping may be important for surgical risk discussion.
Endometriosis may involve somatic nerves, pelvic muscles, and adjacent vessels.
Systematically inspect the:
Also assess the:
When neural disease is suspected, describe the side, nerve segment, lesion extent, signal abnormality, muscle denervation changes, and relationship to adjacent vessels or foramina.
A pelvic endometriosis MRI should include a deliberate search for:
The consensus did not support routine diaphragmatic assessment in every standard pelvic examination. A dedicated upper-abdominal or thoracic protocol may be required when symptoms or prior findings raise suspicion.
The following template can be adapted to local practice.
For each lesion, document size, side, organ or space involved, and surgically relevant distances.
This content is educational and is not patient-specific medical advice. Every phrase, template, classification result, and recommendation must be verified and adapted by a physician using the complete examination, clinical context, current guidelines, and institutional protocol.
Open an examination-specific framework in RadPhrases, adapt it to the findings, and verify it before signing.
