Magnetic resonance imaging for deep infiltrating endometriosis: current concepts, imaging technique and key findings

A Comprehensive Review of the Diagnostic Landscape of Endometriosis: Assessing Tools, Uncovering Strengths, and Acknowledging Limitations

Endometriosis is a prevalent yet often underdiagnosed condition characterized by the presence of endometrial-like tissue outside the uterus, leading to significant morbidity and impaired quality of life. A timely and accurate diagnosis of endometriosis is essential for effective management and improved patient outcomes. This review provides a comprehensive overview of the current diagnostic landscape of endometriosis, including clinical evaluation, imaging modalities, biomarkers, and laparoscopy. The strengths and limitations of each diagnostic approach are critically evaluated, alongside challenges such as delayed diagnosis and misinterpretation of findings. The review emphasizes the importance of multidisciplinary collaboration, standardized diagnostic protocols, and ongoing research to enhance diagnostic accuracy and facilitate early intervention. By addressing these challenges and leveraging emerging technologies, healthcare professionals can improve the diagnosis and management of endometriosis, ultimately enhancing the well-being of affected individuals.

Current Practice Patterns, Challenges, and Need for Education in Performing and Reporting Advanced Pelvic US and MRI to Investigate Endometriosis: A Survey by the Canadian Association of Radiologists Endometriosis Working Group

Purpose: The Canadian Association of Radiologists (CAR) Endometriosis Working Group developed a national survey to evaluate current practice patterns associated with imaging endometriosis using advanced pelvic ultrasound and MRI to inform forthcoming clinical practice guidelines for endometriosis imaging. Methods: The anonymous survey consisted of 36 questions and was distributed electronically to CAR members. The survey contained a mix of multiple choice, Likert scale and open-ended questions intended to collect information about training and certification, current practices and protocols associated with imaging endometriosis, opportunities for quality improvement and continuing professional development. Descriptive statistics were used to summarize the results. Results: Canadian radiologists were surveyed about their experience with imaging endometriosis. A total of 89 responses were obtained, mostly from Ontario and Quebec. Most respondents were community radiologists, and almost 33% were in their first five years of practice. Approximately 38% of respondents reported that they or their institution performed advanced pelvic ultrasound for endometriosis, with most having done so for less than 5 years, and most having received training during residency or fellowship. 70% of respondents stated they currently interpret pelvic endometriosis MRI, with most having 1-5 years of experience. Conclusion: Many radiologists in Canada do not perform dedicated imaging for endometriosis. This may be due to a lack of understanding of the benefits and limited access to training. However, dedicated imaging can improve patient outcomes and decrease repeated surgeries. The results highlight the importance of developing guidelines for these imaging techniques and promoting a multidisciplinary approach to endometriosis management.

Deep Infiltrating Endometriosis: A Pictorial Essay

Deep infiltrating endometriosis (DIE) is a subperitoneal intrusion of endometrial tissue. Resulting endometrial nodules may develop on the uterosacral ligament, urinary tract, rectovaginal, and retrocervical areas, and less commonly in the urinary bladder, thoracic, and neural regions. Genetics, age, and environmental factors determine the progression of the disease. DIE manifests with numerous symptoms, which are similar to unrelated diseases, namely dysmenorrhea, dyspareunia, urinary tract infections, and infertility. Transvaginal ultrasound, magnetic resonance imaging, computed tomography, and physical examination may detect and differentiate endometriosis lesions from other diseases. Its clinical management typically involves laparoscopic surgery and hormonal therapy. These are designed to improve the quality of life and to address individual reproductive goals. This pictorial essay aims to provide clinical cases to highlight the characteristic radiological findings in each diagnostic modality and in addition to elucidate the current clinical management of DIE.

Imaging of Urinary Bladder and Ureteral Endometriosis with Emphasis on Diagnosis and Technique

Endometriosis is a chronic inflammatory gynecological condition affecting 10-15% of women in the reproductive age group. The urinary tract is the second most common extragenital organ system affected by endometriosis, and the urinary bladder and ureter are the two most common sites involved. Involvement of the urinary bladder can cause chronic debilitating symptoms, whereas ureteral involvement may lead to asymptomatic loss of renal function. Both conditions are frequently unsuspected, leading to a delay in diagnosis. Therefore, it is important to recognize this entity early, for which knowledge of imaging appearances and techniques is helpful. In this review article, we describe (a) endometriosis background, pathogenesis, definitions and clinical symptoms, (b) imaging appearance, with emphasis on ultrasound and MRI findings of urinary bladder and ureteric endometriosis, (c) ultrasound technique and MRI sequences useful for making the correct diagnosis, (d) overview of the treatment options and key imaging findings that are important to the surgeon for surgical planning, and (e) a structured reporting template useful for multidisciplinary patient management.

Transvaginal Ultrasound vs. Magnetic Resonance Imaging: What Is the Optimal Imaging Modality for the Diagnosis of Endometriosis?

Endometriosis, an intriguing gynecological illness, poses a substantial health concern for women of reproductive age, despite its widespread occurrence and limited comprehension. The objective of this study is to assess the diagnostic precision of transvaginal sonography (TVS) and pelvic magnetic resonance imaging (MRI) for the identification of deep infiltrated endometriosis (DIE). This study encompassed a cohort of 256 patients exhibiting signs and symptoms of endometriosis, with the aim of assessing the diagnostic accuracy over a span of four years. Both TVS and pelvic MRI were employed in the same centers to analyze each subject. The histopathologic analysis and laparoscopy were the most reliable and widely accepted methods for evaluation. TVS is a reliable diagnostic tool for ovarian endometriomas, obviating the necessity for MRI confirmation. The specificity of TVS in diagnosing ovarian endometriomas is 57.14%, while its sensitivity is 93.78%, resulting in an overall accuracy of 84.47%. In relation to parametrial lesions, the sensitivity, specificity, and accuracy of TVS and MRI were as follows: TVS: 9%, 97%, 32%, MRI: 27.14%, 89.19%, and 40.11%. Concerning the uterosacral lesions, the sensitivity, specificity, and accuracy of TVS and MRI were as follows: TVS:14.63%, 94.74%, and 55%, while MRI: 65.88%, 66.30%, and 66.1%. Regarding rectal endometriosis, the sensitivity, specificity, and accuracy of TVS and MRI were as follows: 69.72%, 76.87%, and 73.82% for TVS, and 66.28%, 94.51%, and 80.79% for MRI. The results of the present study indicate that whereas MRI generally exhibits superior capability in assessing the severity of endometriosis, TVS demonstrates sufficient diagnostic accuracy in DIE comparable to MRI.

Validation of a Salivary miRNA Signature of Endometriosis - Interim Data

BACKGROUND: The discovery of a saliva-based micro–ribonucleic acid (miRNA) signature for endometriosis in 2022 opened up new perspectives for early and noninvasive diagnosis of the disease. The 109-miRNA saliva signature is the product of miRNA biomarkers and artificial intelligence (AI) modeling. We designed a multicenter study to provide external validation of its diagnostic accuracy. We present here an interim analysis. METHODS: The first 200 patients included in the multicenter prospective ENDOmiRNA Saliva Test study (NCT05244668) were included for interim analysis. The study population comprised women from 18 to 43 years of age with a formal diagnosis of endometriosis or with suspected endometriosis. Epidemiologic, clinical, and saliva sequencing data were collected between November 2021 and March 2022. Genomewide miRNA expression profiling by small RNA sequencing using next-generation sequencing (NGS) was performed, and a random forest algorithm was used to assess the diagnostic accuracy. RESULTS: In this interim analysis of the external validation cohort, with a population prevalence of 79.5%, the 109-miRNA saliva diagnostic signature for endometriosis had a sensitivity of 96.2% (95% confidence interval [CI], 93.7 to 97.3%), specificity of 95.1% (95% CI, 85.2 to 99.1%), positive predictive value of 95.1% (95% CI, 85.2 to 99.1%), negative predictive value of 86.7% (95% CI, 77.6 to 90.3%), positive likelihood ratio of 19.7 (95% CI, 6.3 to 108.8), negative likelihood ratio of 0.04 (95% CI, 0.03 to 0.07), and area under the receiver operating characteristic curve of 0.96 (95% CI, 0.92 to 0.98). CONCLUSIONS: The use of NGS and AI in the sequencing and analysis of miRNA provided a saliva-based miRNA signature for endometriosis. Our interim analysis of a prospective multicenter external validation study provides support for its ongoing investigation as a diagnostic tool. (Funded by Ziwig and the Conseil Régional d’Ile de France [Grant EX024087]; ClinicalTrials.gov number, NCT05244668.)

Deep Infiltrating Endometriosis: Diagnostic Accuracy of Preoperative Magnetic Resonance Imaging with Respect to Morphological Criteria

Several current guidelines recommend imaging in the diagnostic work-up of deep infiltrating endometriosis (DIE). The purpose of this retrospective diagnostic test study was to evaluate the diagnostic accuracy of MRI compared to laparoscopy for the identification of pelvic DIE, considering lesion morphology using MRI. In all, 160 consecutive patients were included who received pelvic MRI for evaluation of endometriosis between October 2018 and December 2020 and underwent subsequent laparoscopy within 12 months of the MRI examination. MRI findings were categorized for suspected DIE using the Enzian classification and were additionally graded using a newly suggested deep infiltrating endometriosis morphology score (DEMS). Endometriosis was diagnosed in 108 patients (all types, i.e., purely superficial and DIE), of which 88 cases were diagnosed with DIE and 20 with solely superficial peritoneal endometriosis (i.e., not deep infiltrating endometriosis/DIE). The overall positive and negative predictive values of MRI for the diagnosis of DIE, including lesions with assumed low and medium certainty of DIE on MRI (DEMS 1-3), were 84.3% (95% CI: 75.3-90.4) and 67.8% (95% CI: 60.6-74.2), respectively, and 100.0% and 59.0% (95% CI: 54.6-63.3) when strict MRI diagnostic criteria were applied (DEMS 3). Overall sensitivity of MRI was 67.0% (95% CI: 56.2-76.7), specificity was 84.7% (95% CI: 74.3-92.1), accuracy was 75.0% (95% CI: 67.6-81.5), positive likelihood ratio (LR+) was 4.39 (95% CI: 2.50-7.71), negative likelihood ratio (LR-) was 0.39 (95% CI: 0.28-0.53), and Cohen's kappa was 0.51 (95% CI: 0.38-0.64). When strict reporting criteria are applied, MRI can serve as a method to confirm clinically suspected DIE.

Comparison between CT-enterography and MR-enterography for the diagnosis of right-sided deep infiltrating endometriosis of the bowel

OBJECTIVE

To compare computed tomography-enterography (CTE) and magnetic resonance-enterography (MRE) in the detection of right-sided bowel deep infiltrating endometriosis (DIE).

MATERIALS AND METHODS

Fifty women with DIE who underwent preoperatively CTE and MRE were included. CTE and MRE were first analyzed separately by two independent readers who analyzed five bowel segments (cecum, appendix, ileocecal junction, distal ileum and proximal small bowel [i.e., proximal ileum and jejunum]) for the presence of DIE and then interpreted in consensus. CTE, MRE and CTE with MRE were compared in terms of sensitivity, specificity and accuracy. Interobserver agreement was assessed with kappa (κ) test.

RESULTS

Using the reference standard 25 out 250 bowel segments were involved by DIE in 18 women and 225 were free of DIE. Sensitivity, specificity, and accuracy of CTE were 60% (95% confidence interval [CI]: 39-79), 93% (95% CI: 89-96) and 90% (95% CI: 85-93) for Reader 1, respectively, and 52% (95% CI: 31-72), 99% (95% CI: 97-100) and 94% (95% CI: 91-97) for Reader 2, with no differences in sensitivity (P = 0.564) and specificity (P = 0.181) between readers and fair interobserver agreement (κ = 0.37). For MRE these figures were 52% (95% CI: 31-72), 92% (95% CI: 88-95) and 88% (95% CI: 84-92) for Reader 1 and 60% (95% CI: 39-79), 99% (95% CI: 96-100) and 95% (95% CI: 91-97) for Reader 2, with no differences in sensitivity (P = 0.157) and specificity (P = 0.061) between readers and fair interobserver agreement (κ = 0.31). Significant differences in sensitivity (20%; 95% CI: 7-41) were found between CTE + MRE vs. CTE alone for Reader 1 and vs. MRE alone for Reader 2 (P = 0.041 for both) CONCLUSION: CTE and MRE have not different sensitivities and convey only fair interobserver agreement but are highly specific for the diagnosis of right-sided bowel DIE. CTE and MRE are complementary because they improve the detection of DIE implants when used in combination.

Endometriosis and Opioid Receptors: Are Opioids a Possible/Promising Treatment for Endometriosis?

Endometriosis (EM), defined as the presence of endometrial-like tissue with surrounding smooth muscle cells outside the uterus, is a disregarded gynecological disease reported to affect 6-10% of women of reproductive age, with 30-50% of them suffering from chronic pelvic pain and infertility. Since the exact pathogenic mechanisms of EM are still unclear, no curative therapy is available. As pain is an important factor in EM, optimal analgesia should be sought, which to date has been treated primarily with non-steroidal anti-inflammatory drugs (NSAIDs), metamizole or, in extreme cases, opioids. Here, we review the pain therapy options, the mechanisms of pain development in EM, the endogenous opioid system and pain, as well as the opioid receptors and EM-associated pain. We also explore the drug abuse and addiction to opioids and the possible use of NOP receptors in terms of analgesia and improved tolerability as a target for EM-associated pain treatment. Emerging evidence has shown a promising functional profile of bifunctional NOP/MOP partial agonists as safe and nonaddictive analgesics. However, until now, the role of NOP receptors in EM has not been investigated. This review offers a thought which still needs further investigation but may provide potential options for relieving EM-associated pain.

Endometriosis: A multimodal imaging review

Endometriosis is a chronic inflammatory disorder characterized endometrial-like tissue present outside of the uterus, affecting approximately 10% of reproductive age women. It is associated with abdomino-pelvic pain, infertility and other non - gynecologic symptoms, making it a challenging diagnosis. Several guidelines have been developed by different international societies to diagnose and classify endometriosis, yet areas of controversy and uncertainty remains. Transvaginal ultrasound (TV-US) is the first-line imaging modality used to identify endometriosis due to its accessibility and cost-efficacy. Enhanced sonographic techniques are emerging as a dedicated technique to evaluate deep infiltrating endometriosis (DIE), depending on the expertise of the sonographer as well as the location of the lesions. MRI is an ideal complementary modality to ultrasonography for pre-operative planning as it allows for a larger field-of-view when required and it has high levels of reproducibility and tolerability. Typically, endometriotic lesions appear hypoechoic on ultrasonography. On MRI, classical features include DIE T2 hypointensity, endometrioma T2 hypointensity and T1 hyperintensity, while superficial peritoneal endometriosis (SPE) is described as a small focus of T1 hyperintensity. Imaging has become a critical tool in the diagnosis, surveillance and surgical planning of endometriosis. This literature review is based mostly on studies from the last two decades and aims to provide a detailed overview of the imaging features of endometriosis as well as the advances and usefulness of different imaging modalities for this condition.

Mimics of cancer in pregnancy

Pregnancy is a remarkable time of pronounced growth and development of the fetus. Benign pathologies outside of the uterus, including those containing hormonally responsive tissue which undergo physiologic changes and other incidentally identified lesions, may mimic malignancy on clinical evaluation and imaging. A detailed history and physical exam, ultrasound and non-contrast magnetic resonance imaging features and comparison with prior imaging if available may help to narrow the list of potential differential diagnoses. Follow-up imaging in the postpartum period is often vital to confirm benignity and, in some cases, sampling to confirm the diagnosis is necessary. This review will cover the clinical, pathological and multimodality imaging features of numerous potential mimickers of cancer in the setting of pregnancy organized by organ systems. The goal is to better equip abdominal radiologists to accurately identify benign disease and help guide further imaging or follow-up recommendations to avoid unnecessarily aggressive intervention and improve patient care.

Transvaginal Ultrasound vs. Magnetic Resonance Imaging (MRI) Value in Endometriosis Diagnosis

(1) Background: Endometriosis is a widespread gynecological condition that causes chronic pelvic discomfort, dysmenorrhea, infertility, and impaired quality of life in women of reproductive age. Clinical examination, transvaginal ultrasonography (TVS), and magnetic resonance imaging (MRI) are significant preoperative non-invasive diagnosis procedures for the accurate assessment of endometriosis. Although TVS is used as the primary line for diagnosis, MRI is commonly utilized to achieve a better anatomical overview of the entire pelvic organs. The aim of this systematic review article is to thoroughly summarize the research on various endometriosis diagnosis methods that are less invasive. (2) Methods: To find relevant studies, we examined electronic databases, such as MEDLINE/PubMed, Cochrane, and Google Scholar, choosing 70 papers as references. (3) Results: The findings indicate that various approaches can contribute to diagnosis in different ways, depending on the type of endometriosis. For patients suspected of having deep pelvic endometriosis, transvaginal sonography should be the first line of diagnosis. Endometriosis cysts are better diagnosed with TVS, whereas torus, uterosacral ligaments, intestine, and bladder endometriosis lesions are best diagnosed using MRI. When it comes to detecting intestine or rectal nodules, as well as rectovaginal septum nodules, MRI should be the imaging tool of choice. (4) Conclusions: When diagnosing DE (deep infiltrative endometriosis), the examiner’s experience is the most important criterion to consider. In the diagnosis of endometriosis, expert-guided TVS is more accurate than routine pelvic ultrasound, especially in the deep infiltrative form. For optimal treatment and surgical planning, accurate preoperative deep infiltrative endometriosis diagnosis is essential, especially because it requires a multidisciplinary approach.

MicroRNome analysis generates a blood-based signature for endometriosis

Endometriosis, characterized by endometrial-like tissue outside the uterus, is thought to affect 2–10% of women of reproductive age: representing about 190 million women worldwide. Numerous studies have evaluated the diagnostic value of blood biomarkers but with disappointing results. Thus, the gold standard for diagnosing endometriosis remains laparoscopy. We performed a prospective trial, the ENDO-miRNA study, using both Artificial Intelligence (AI) and Machine Learning (ML), to analyze the current human miRNome to differentiate between patients with and without endometriosis, and to develop a blood-based microRNA (miRNA) diagnostic signature for endometriosis. Here, we present the first blood-based diagnostic signature obtained from a combination of two robust and disruptive technologies merging the intrinsic quality of miRNAs to condense the endometriosis phenotype (and its heterogeneity) with the modeling power of AI. The most accurate signature provides a sensitivity, specificity, and Area Under the Curve (AUC) of 96.8%, 100%, and 98.4%, respectively, and is sufficiently robust and reproducible to replace the gold standard of diagnostic surgery. Such a diagnostic approach for this debilitating disorder could impact recommendations from national and international learned societies.

Salivary MicroRNA Signature for Diagnosis of Endometriosis

BACKGROUND

Endometriosis diagnosis constitutes a considerable economic burden for the healthcare system with diagnostic tools often inconclusive with insufficient accuracy. We sought to analyze the human miRNAome to define a saliva-based diagnostic miRNA signature for endometriosis.

METHODS

We performed a prospective ENDO-miRNA study involving 200 saliva samples obtained from 200 women with chronic pelvic pain suggestive of endometriosis collected between January and June 2021. The study consisted of two parts: (i) identification of a biomarker based on genome-wide miRNA expression profiling by small RNA sequencing using next-generation sequencing (NGS) and (ii) development of a saliva-based miRNA diagnostic signature according to expression and accuracy profiling using a Random Forest algorithm.

RESULTS

Among the 200 patients, 76.5% (n = 153) were diagnosed with endometriosis and 23.5% (n = 47) without (controls). Small RNA-seq of 200 saliva samples yielded ~4642 M raw sequencing reads (from ~13.7 M to ~39.3 M reads/sample). Quantification of the filtered reads and identification of known miRNAs yielded ~190 M sequences that were mapped to 2561 known miRNAs. Of the 2561 known miRNAs, the feature selection with Random Forest algorithm generated after internally cross validation a saliva signature of endometriosis composed of 109 miRNAs. The respective sensitivity, specificity, and AUC for the diagnostic miRNA signature were 96.7%, 100%, and 98.3%.

CONCLUSIONS

The ENDO-miRNA study is the first prospective study to report a saliva-based diagnostic miRNA signature for endometriosis. This could contribute to improving early diagnosis by means of a non-invasive tool easily available in any healthcare system.