Agreement and reproducibility in identification of endometriosis using magnetic resonance imaging

Bowel wall thickness measured by MRI is useful for early diagnosis of bowel endometriosis

OBJECTIVE

To evaluate MRI features of bowel endometriosis (BE) and verify its clinical significance compared with pathological diagnosis.

MATERIALS AND METHODS

Since 2018, patients clinically diagnosed with deep endometriosis (DE) and planned to undergo surgery were enrolled prospectively. MRI parameters including traction, thickening sign of the rectum, obliteration of the Douglas Pouch, sign of adenomyosis, and pelvic adhesion were extracted. Uni- and multi-variate analyses were performed to explore their association with pathological diagnosis of BE. ROC curve was utilized to ascertain the appropriate cutoff value for predicting the presence and assessing the severity of BE.

RESULTS

A total of 226 patients with DE were recruited, and 154 BE cases were pathologically confirmed. Logistic regression analysis revealed that thickness of the rectal wall, traction sign of the rectum, and obliteration of the Douglas Pouch were independent factors to predict the presence of BE with the OR 1.59 (95% CI: 1.29-1.96), 0.24 (95% CI: 0.09-0.67), and 0.17 (95% CI: 0.07-0.40), respectively (p all < 0.01). A cutoff value of 6.0 mm for the thickness of rectal wall resulted in the highest predictive value of BE (specificity: 90.3%; sensitivity: 78.6%). For patients with measured thickness of the rectal wall over 6.0 mm, 72.1% (93/129) was confirmed BE with lesions infiltrated more than muscular layer.

CONCLUSION

This prospective study indicates that based on precise definition of visualized features on MRI images, BE could be recognized pre-operatively. DE patients with thickness of rectal wall exceeding 6.0 mm have a greater probability of BE.

CLINICAL RELEVANCE STATEMENT

Based on precise definition of visualized features and accurate measurement on MRI images, bowel infiltrating among deep endometriosis patients could be recognized pre-operatively.

KEY POINTS

• Precise definition of measurable MRI parameters made it possible for early detection of bowel endometriosis. • Thickening sign, traction sign of the rectum, and obliteration of the Douglas Pouch were typical radiological indicators for bowel endometriosis. • Bowel involvement is more sensitive to be detected among pelvic deep endometriosis patients with the thickness of the rectal wall over 6.0 mm.

Application of the #Enzian classification for endometriosis on MRI: prospective evaluation of inter- and intraobserver agreement

Objectives

The purpose of this investigation was to evaluate the inter- and intraobserver variability of the updated #Enzian classification of endometriosis on MRI and to evaluate the influence of reader experience on interobserver concordance.

Methods

This was a prospective single-center study. All patients were included who received an MRI of the pelvis for evaluation of endometriosis between March and July 2023 and who have provided written informed consent. Images were reviewed independently for endometriosis by three radiologists, utilizing the MRI-applicable categories of the #Enzian classification. Two radiologists had experience in pelvic MRI and endometriosis imaging. One radiologist had no specific experience in pelvic MRI and received a one-hour briefing beforehand.

Results

Fifty consecutive patients (mean age, 34.9 years ±8.6 [standard deviation]) were prospectively evaluated. Interobserver agreement was excellent for diagnosis of deep infiltrating endometriosis (Fleiss' kappa: 0.89; 95% CI 0.73-1.00; p < 0.001) and endometriomas (Fleiss' kappa: 0.93; 95% CI 0.77-1.00; p < 0.001). For the experienced readers, interobserver agreement in the assessment of compartments A, B and C was excellent (κw ranging from 0.84; 95% CI 0.71-0.97; p < 0.001 to 0.89; 95% CI 0.82-0.97; p < 0.001). For the pairings of the experienced readers to the reader without specific experience in pelvic MRI, agreement was substantial to excellent (κw ranging from 0.64; 95% CI 0.44-0.85; p < 0.001 to 0.91; 95% CI 0.84-0.98; p < 0.001). Intraobserver variability was excellent for compartments A, B and C (κw ranging from 0.85; 95% CI 0.73-0.96; p < 0.001 to 0.95; 95% CI 0.89-1.00; p < 0.001).

Conclusion

With sufficient experience, the #Enzian classification enables the achievement of excellent inter- and intraobserver agreement in MRI-based diagnosis of deep infiltrating endometriosis and endometriomas.

Magnetic resonance imaging presentation of diffuse and focal adenomyosis before and after pregnancy

RESEARCH QUESTION

Is there a change in magnetic resonance imaging (MRI) criteria of diffuse and focal phenotypes of adenomyosis before and after pregnancy?

DESIGN

A retrospective, monocentric, observational study in a single academic tertiary referral centre for endometriosis diagnosis and management. Women were followed for symptomatic adenomyosis, and without a prior history of surgery who give birth after 24+0 weeks. For each patient, pelvic MRI pre- and post-pregnancy was performed by two experienced radiologists with the same image acquisition protocol. Diffuse and focal adenomyosis MRI presentation were analysed before and after pregnancy.

RESULTS

Between January 2010 and September 2020, of the 139 patients analysed, 96 (69.1%) had adenomyosis at MRI distributed as follow: 22 (15.8%) presented diffuse adenomyosis, 55 (39.6%) focal adenomyosis and 19 (13.7%) both phenotypes. The frequency of isolated diffuse adenomyosis on MRI was significantly lower before versus after pregnancy (n = 22 [15.8%] versus n = 41 [29.5%], P = 0.01). The frequency of isolated focal adenomyosis was significantly higher before pregnancy than after pregnancy (n = 55 [39.6%] versus n = 34 [24.5%], P = 0.01). The mean volume of all focal adenomyosis lesions on MRI decreased significantly after pregnancy, from 6.7 ± 2.5 mm3 to 6.4 ± 2.3 mm3, P = 0.01.

CONCLUSION

The current data indicate that, based on MRI, there is an increase in diffuse adenomyosis and a decrease in focal adenomyosis after pregnancy.

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.

Strengths and limitations of diagnostic tools for endometriosis and relevance in diagnostic test accuracy research

Endometriosis is a chronic systemic disease that can cause pain, infertility and reduced quality of life. Diagnosing endometriosis remains challenging, which yields diagnostic delays for patients. Research on diagnostic test accuracy in endometriosis can be difficult due to verification bias, as not all patients with endometriosis undergo definitive diagnostic testing. The purpose of this State-of-the-Art Review is to provide a comprehensive update on the strengths and limitations of the diagnostic modalities used in endometriosis and discuss the relevance of diagnostic test accuracy research pertaining to each. We performed a comprehensive literature review of the following methods: clinical assessment including history and physical examination, biomarkers, diagnostic imaging, surgical diagnosis and histopathology. Our review suggests that, although non-invasive diagnostic methods, such as clinical assessment, ultrasound and magnetic resonance imaging, do not yet qualify formally as replacement tests for surgery in diagnosing all subtypes of endometriosis, they are likely to be appropriate for advanced stages of endometriosis. We also demonstrate in our review that all methods have strengths and limitations, leading to our conclusion that there should not be a single gold-standard diagnostic method for endometriosis, but rather, multiple accepted diagnostic methods appropriate for different circumstances. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

A review of more than 2000 cases of site-specific pelvic endometriosis rates by MRI: a guide to minimizing under/overdiagnosis non-invasively

Objectives

To statistically study the incidence of endometrioma and deep infiltrating endometriosis (DIE) in various anatomical sites and to illustrate the significance and potential implications for each site. Furthermore, to improve the knowledge of the community for a non-invasive diagnosis alternative to laparoscopy.

Methods

This study includes 2040 patients who had been referred with clinical evidence of pelvic endometriosis. These patients had been examined and undergone transvaginal sonography by the referring gynecologists. The imaging modality used to discover and locate various anatomical locations of involvement was MRI with contrast. Two radiologists with expertise in endometriosis separately assessed the patients' MRIs and highlighted the involved areas.

Results

In total, 79.1% were positive for either endometrioma or DIE. We detected both DIE and ovarian endometrioma in 78.2% of positive cases. Isolated endometrioma or DIE was present exclusively in 13.7% and 8.1% of patients, respectively. Uterosacral ligaments were detected as the most common (73.8%) site of DIE involvements and in 2.9% of cases were the sole affected location. Interestingly, very rare independent involvement of the genitourinary tract was seen in two patients.

Conclusions

In this study, MRI was used to assess the likely involvement sites of endometrioma and DIE, as well as the frequency of incidences in various places and their relationships over a large dataset. Understanding the possibly involved sites, their statistics, and their co-existence can provide radiologists with a roadmap for non-invasive endometriosis diagnosis and treatment planning. These principles should hopefully assist reduce under- and overdiagnosis.

MRI and Adenomyosis: What Can Radiologists Evaluate?

Uterine adenomyosis is a common benign condition defined by the presence of heterotopic endometrial glands and stroma within the myometrium. Adenomyosis is often related to infertility and other adverse pregnancy outcomes. Modern imaging techniques allow the non-invasive diagnosis of adenomyosis and, in this framework, Magnetic Resonance Imaging (MRI) has assumed a central role due to its high diagnostic accuracy in the detection of adenomyosis. Currently, there is still a lack of international consensus on adenomyosis diagnostic criteria and classification, despite the fact that an agreed reporting system would promote treatment outcomes and research. This review aims to emphasize the important contribution of MRI to the diagnosis of adenomyosis and to highlight how, thanks to the great tissue differentiation provided by MRI, it is possible to identify the main direct (cystic component) and indirect (junctional zone features) signs of adenomyosis and to distinguish its various subtypes according to different MRI-based classifications. We also explored the main MRI criteria to identify the most common pitfalls and differential diagnoses of adenomyosis, whose features should be considered to avoid misdiagnosis.

Can New ENZIAN Score 2020 Represent a Staging System Improving MRI Structured Report?

Structured reporting systems for endometriotic disease are gaining a central role in diagnostic imaging: our aim is to evaluate applicability and the feasibility of the recent ENZIAN score (2020) assessed by MRI. A total of 60 patients with suspected tubo–ovarian/deep endometriosis were retrospectively included in our study according to the following criteria: availability of MR examination; histopathological results from laparoscopic or surgical treatment; patients were not assuming estro-progestin or progestin therapy. Three different readers (radiologists with 2-, 5-, and 20-years of experience in pelvic imaging) have separately assigned a score according to the ENZIAN score (revised 2020) for all lesions detected by magnetic resonance imaging (MRI). Our study showed a high interobserver agreement and feasibility of the recent ENZIAN score applied to MRI; on the other hand, our experience highlighted some limitations mainly due to MRI’s inability to assess tubal patency and mobility, as required by the recent score (2020). In view of the limitations which arose from our study, we propose a modified MRI-ENZIAN score that provides a complete structured reporting system, more suitable for MRI. The high interobserver agreement of the recent ENZIAN score applied to MRI confirms its validity as a complete staging system for endometriosis, offering a shared language between radiologists and surgeons.

Performance of imaging interpretation, intra- and inter-reader agreement for diagnosis of pelvic endometriosis: comparison between an abbreviated and full MRI protocol

PURPOSE

To compare the performance of imaging interpretation, intra- and inter-reader agreement between an abbreviated (aMRI) and full (fMRI) MRI protocol for diagnosis of pelvic endometriosis.

METHODS

Seventy consecutive fMRI exams performed under suspicion of pelvic endometriosis were selected. Four radiologists (Rd) (1-10 years experience) independently evaluated presence/absence of endometriosis at 9 anatomic sites (AS). The readers evaluated aMRI (coronal T2 TSE volumetric images and axial T1 GRE fat-sat without contrast, extracted from fMRI) and fMRI protocols randomly, with at least 4 weeks interval between readings. The degree of confidence for diagnosis at each AS was evaluated with a 1-3 Likert Scale (1: low; 3: high). Intra- and inter-reader agreement between protocols were evaluated by kappa statistics and took reading experience into account. The gold standard for assessing the performance of imaging interpretation (sensitivity, specificity and accuracy) used a consensus reading of two other Rd (> 15 years experience).

RESULTS

There was no significant difference in the accuracy of imaging interpretation between the abbreviated (0.83-0.86) and full (0.83-0.87) protocols (p = 0.15). Intra-reader agreement between protocols ranged from substantial to almost perfect (0.74-0.96). A substantial inter-reader agreement was found for both protocols for readers with similar levels of experience (0.67-0.69) and in the global analysis (0.66 for both protocols). No difference was found in terms of degree of confidence between protocols, for all readers.

CONCLUSION

An abbreviated MRI protocol for pelvic endometriosis provided an accuracy of interpretation comparable to that of a complete protocol, with similar degrees of confidence and reproducibility, regardless the level of experience.

Imaging for evaluation of endometriosis and adenomyosis

Endometriosis and adenomyosis are two frequent diseases that impair women's quality of life by causing pain and infertility. Both endometriosis and adenomyosis are heterogeneous diseases that manifest as different forms. Adenomyosis may be described as diffuse adenomyosis, focal adenomyosis especially of the outer myometrium and cystic adenomyoma. Endometriosis has three phenotypes: superficial peritoneal endometriosis (SUP), ovarian endometrioma (OMA), and deep infiltrating endometriosis (DIE). These two diseases are closely linked, and it is now clear that adenomyosis can either arise on its own or coexist with endometriosis. There is a strong clinical relationship between endometriosis and adenomyosis according to their respective phenotypes. Various classifications are available to describe both diseases. Transvaginal ultrasonography (TVUS) and/or pelvic magnetic resonance imaging (MRI) are the first examination performed when endometriosis or adenomyosis are suspected. These two imaging techniques, used in a combination manner, allow accurate description of both endometriosis and adenomyosis, to assess the diagnosis and to improve clinical and surgical care. In this review, we described the different imaging aspects of endometriosis and adenomyosis to help the less experienced radiologist or gynecologist in the diagnosis and evaluation of those diseases.

Magnetic resonance imaging classification of deep pelvic endometriosis: description and impact on surgical management

STUDY QUESTION

Is an MRI classification of deep pelvic endometriosis (DE) able to correctly predict the risk of DE surgery.

SUMMARY ANSWER

A new radiological classification, that we have called the deep pelvic endometriosis index (dPEI) classification, is accurate and reproducible to assess the extension of the disease in central and lateral compartments and well correlated with operating time, hospital stay duration and the risk of voiding dysfunction.

WHAT IS KNOWN ALREADY

Few imaging classifications are currently available to predict the extent of DE to help preoperative assessment of surgical outcomes and provide the patient with objective information about the risk of surgical complications.

STUDY DESIGN, SIZE, DURATION

Retrospective monocentric observational study was conducted between 01 January 2017 and 31 December 2018 and included 150 women (mean age = 34.5 years, 20-52 years) with DE on MRI and who subsequently underwent surgery.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two radiologists independently graded the disease according to MRI-based Enzian classification (A (rectovaginal septum and vagina locations), B (uterosacral locations) and C (rectosigmoid locations)) and a new radiological classification, that we have called the dPEI, that grades the severity of DE as: mild, moderate or severe DE. MRI findings and classification were correlated with surgical and pathological results.

MAIN RESULTS AND THE ROLE OF CHANCE

MRI-based and surgical Enzian classifications were concordant for A lesions in 78.7% (118/150), for B lesions in 34.7% (52/150) and for C lesions in 82.7% (124/150). Operating time and hospital stays were longer in Group A2 (rectovaginal septum and vagina, 1-3 cm) compared to A0, B2 (uterosacral, 1-3 cm) compared to B0, C3 (rectosigmoid >3 cm) compared to C2 (rectosigmoid 1-3 cm) or C0 (P < 0.001), in severe compared to moderate DE patients, and in moderate compared to mild extensive patients (P < 0.01). Patients with vaginal or rectosigmoid involvement were respectively six and three times more likely to experience high-grade complications according to Clavien-Dindo classification than patients without vaginal or rectosigmoid disease (P < 0.001). Postoperative voiding dysfunction was correlated with A lesions (odds ratio (OR) = 6.82, 95% CI 2.34-20.5), moderate or severe DE (OR = 4.15, 95% CI 1.26-17.9), the presence of at least unilateral lateral pelvic involvement (OR = 3.6, 95% CI 1.14-11.2, P = 0.03) and C lesions (OR = 2.6, 95% CI 1.03-6.8, P < 0.01).

LIMITATIONS, REASONS FOR CAUTION

The study was conducted in an expert center and needs to be validated in a multicenter study. There is a limited number of patients with lateral pelvic endometriosis beyond the parietal fascia, probably due to the low prevalence of this disease presentation.

WIDER IMPLICATIONS OF THE FINDINGS

MRI imaging can be used to accurately predict postoperative complications for women with DE. This may help the clinician to preoperatively inform a patient about the risks of surgery. Larger clinical studies are required to validate these results.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. I.T.N.: Remunerated lecture GE, Hologic, Guerbet, Canon; Advisory board: Siemens - These relationships are on the topic of breast imaging, not related to the topic of this paper. Other coauthors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

IDEAL study: magnetic resonance imaging for suspected deep endometriosis assessment prior to laparoscopy is as reliable as radiological imaging as a complement to transvaginal ultrasonography

OBJECTIVE

To compare the value of using one-stop magnetic resonance imaging (MRI) vs standard radiological imaging as a supplement to transvaginal ultrasonography (TVS) for the preoperative assessment of patients with endometriosis referred for surgery in a tertiary care academic center.

METHODS

This prospective observational study compared the diagnostic value of the standard preoperative imaging practice of our center, which involves expert TVS complemented by intravenous urography (IVU) for the evaluation of the ureters and double-contrast barium enema (DCBE) for the evaluation of the rectum, sigmoid and cecum, with that of expert TVS complemented by a 'one-stop' MRI examination evaluating the upper abdomen, pelvis, kidneys and ureters as well as rectum and sigmoid on the same day, for the preoperative triaging of 74 women with clinically suspected deep endometriosis. The findings at laparoscopy were considered the reference standard. Patients were stratified according to their need for monodisciplinary surgical approach, carried out by gynecologists only, or multidisciplinary surgical approach, involving abdominal surgeons and/or urologists, based on the extent to which endometriosis affected the reproductive organs, bowel, ureters, bladder or other abdominal organs.

RESULTS

Our standard preoperative imaging approach and the combined findings of TVS and MRI had similar diagnostic performance, resulting in correct stratification for a monodisciplinary or a multidisciplinary surgical approach of 67/74 (90.5%) patients. However, there were differences between the estimation of the severity of disease by DCBE and MRI. The severity of rectal involvement was underestimated in 2.7% of the patients by both TVS and DCBE, whereas it was overestimated in 6.8% of the patients by TVS and/or DCBE.

CONCLUSIONS

Complementary to expert TVS, 'one-stop' MRI can predict intraoperative findings equally well as standard radiological imaging (IVU and DCBE) in patients referred for endometriosis surgery in a tertiary care academic center. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Intra- and interobserver reproducibility of pelvic ultrasound for the detection and measurement of endometriotic lesions

STUDY QUESTION

What is the interobserver and intraobserver reproducibility of pelvic ultrasound for the detection of endometriotic lesions?

SUMMARY ANSWER

Pelvic ultrasound is highly reproducible for the detection of pelvic endometriotic lesions.

WHAT IS KNOWN ALREADY

Transvaginal ultrasound (TVS) has been widely adopted as the first-line assessment for the diagnosis and assessment of pelvic endometriosis. Severity of endometriosis as assessed by ultrasound has been shown to have good concordance with laparoscopy (kappa 0.79). The reproducibility of TVS for assessment of ovarian mobility and pouch of Douglas obliteration using the 'sliding sign' has already been described in the literature. However, there is no available data in the literature to demonstrate the intraobserver repeatability of measurements for endometriotic cysts and nodules.

STUDY DESIGN SIZE DURATION

This was a prospective observational cross-sectional study conducted over a period of 12 months. We included 50 consecutive women who were all examined by two operators (A and B) during their clinic attendance.

PARTICIPANTS/MATERIALS SETTING METHODS

The study was carried out in a specialist endometriosis centre. We included all consecutive women who had ultrasound scans performed independently by two experienced operators during the same visit to the clinic. The outcomes of interest were the inter- and intraobserver reproducibility for the detection of endometriotic lesions. We also assessed repeatability of the measurements of lesion size.

MAIN RESULTS AND THE ROLE OF CHANCE

There was a good level of agreement between operator A and operator B in detecting the presence of pelvic endometriotic lesions (k = 0.72). There was a very good level of agreement between operators in identifying endometriotic cysts (k = 0.88) and a good level of agreement in identifying endometriotic nodules (k = 0.61). The inter- and intraobserver repeatability of measuring endometriotic cysts was excellent (intra-class correlation (ICC) ≥ 0.98). There was good interobserver measurement repeatability for bowel nodules (ICC 0.88), but the results for nodules in the posterior compartment were poor (ICC 0.41). The intraobserver repeatability for nodule size measurements was good for both operators (ICC ≥0.86).

LIMITATIONS REASONS FOR CAUTION

Within this cohort, there was insufficient data to perform a separate analysis for nodule size in the anterior compartment. All examinations were performed within a specialised unit with a high prevalence of deep endometriosis. Our findings may not apply to operators without intensive ultrasound training in the diagnosis of pelvic endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

These findings are important because ultrasound has been widely accepted as the first-line investigation for the diagnosis of pelvic endometriosis, which often determines the need for future investigations and treatment. The detection and measurement of bowel nodules is essential for anticipation of surgical risk and planning surgical excision.

STUDY FUNDING/COMPETING INTERESTS

The authors have no conflict of interest. No funding was obtained for this work.

Magnetic resonance imaging presentation of deep infiltrating endometriosis nodules before and after pregnancy: A case series

OBJECTIVE

To compare the magnetic resonance imaging (MRI) features of deep infiltrating endometriosis (DIE) lesions before and after pregnancy.

DESIGN

Retrospective study.

SETTING

A single French university tertiary referral hospital.

PATIENTS

Twenty-one women without a prior history of surgery for endometriosis with a radiological diagnosis by MRI with two sets of examinations performed before and after pregnancy.

INTERVENTIONS

The volumes of the lesions were compared using the same protocol before and after pregnancy based on MRI (1.5 T) examinations by a single experienced radiologist who is a referring practitioner for image-based diagnosis of endometriosis.

MAIN OUTCOME MEASURE(S)

The DIE lesion volume.

MEASUREMENTS AND MAIN RESULTS

Between October 2012 and December 2016, a total of 21 patients (67 lesions) were included and compared before and after pregnancy. The mean time interval between the MRI before pregnancy and delivery was 19.6 ± 8.5 months (median: 17.6, IQR 13.5-25.2 months). The mean time interval between delivery and the MRI after pregnancy was 11.0 ± 6.4 months (median: 8.3, IQR 6-15.2 months). The mean overall DIE lesion volume by MRI was significantly higher before pregnancy compared to after pregnancy (2,552 ± 3,315 mm3 vs. 1,708 ± 3,266 mm3, respectively, p < 0.01). The mean volume by MRI of the largest lesion of each patient was significantly higher before pregnancy compared to after pregnancy (4,728 ± 4,776 mm3 vs. 3165 ± 5299 mm3; p < 0.01).

CONCLUSION

Our data indicate a favorable impact of pregnancy on DIE lesion volumes as measured by MRI.

Does the clinical information play a role in the magnetic resonance diagnostic confidence analysis of ovarian and deep endometriosis?

OBJECTIVE:

Some recent studies have explored how the experience in the observers change their performance in the endometriosis detection using MRI but the effects of the clinical information remains uncertain. The purpose of this study was to assess the effect of the clinical information in the diagnostic confidence in the MRI diagnosis of endometriosis.

METHODS AND MATERIALS:

Institutional Review Board was obtained. This study is compliant to STARD method. 80 patients (mean age 32 years; range 19 - 46 years) who had undergone MRI study and surgery for suspected endometriosis were retrospectively evaluated. MRI exams were performed with a 1.5 T scanner and the following five locations were assessed: ovary, anterior compartment, vaginal fornix, utero-sacral ligaments, and Rectum\Sigmoid\Pouch of Douglas. Data sets were evaluated twice on a 5-point scale by four radiologists with different level of expertise; the first time blinded to the clinical information and the second time, after 3 months together with the clinical chart. Statistical analysis included receiver operating characteristics curve analysis, the Cohen weighted test and sensitivity, specificity, positive predictive value, negative predictive value, accuracy, LR+ and LR-.

RESULTS:

A total of 140 localization of endometriosis (47 endometriomas and 93 endometriotic nodules) were found. The pairwise comparison demonstrated that in all cases the presence of clinical information improved the Az value. The concordance analysis indicated a mixed pattern from modest agreement (weighted κ value 0.556 for anterior compartment) to excellent agreement values (weighted κ value 0.867 for ovarian endometriomas).

CONCLUSION:

The results of our study suggest that clinical information is useful in diagnosing endometriosis in general anterior compartment, but not in other locations. Less experienced radiologists (resident) may benefit from it at utero-sacral ligaments or Rectum\Sigmoid\Pouch of Douglas.

ADVANCES IN KNOWLEDGE:

In this era of sometimes indiscriminate use of diagnostic methods, it is important to emphasis the context for interpretation of diagnostic results. Our paper confirms that clinical information is useful in diagnosing endometriosis.

Deep Infiltrating Endometriosis: Comparison Between 2-Dimensional Ultrasonography (US), 3-Dimensional US, and Magnetic Resonance Imaging

OBJECTIVES

To evaluate the diagnostic accuracy of 2-dimensional (2D) and 3-dimensional (3D) transvaginal ultrasonography (US) in comparison with magnetic resonance imaging (MRI) for identification of deep infiltrating endometriosis.

METHODS

In this prospective observational study, 159 premenopausal women who underwent surgery for a clinical suspicion of deep infiltrating endometriosis were prospectively enrolled. All women underwent 2DUS, 3DUS, and MRI. The following 3 locations of deep endometriosis were considered: (1) intestinal; (2) other posterior lesions (retrocervical septum, rectovaginal septum, uterosacral ligaments, and vaginal fornix); and (3) anterior. The sensitivity, specificity, positive predictive value, and negative predictive value of 2D and 3D transvaginal US in comparison with MRI were determined.

RESULTS

Intestinal deep infiltrating endometriosis was identified by 2DUS in 56 of 66 patients, by 3DUS in 59 of 66, and by MRI in 61 of 66. A receiver operating characteristic curve analysis showed optimal results for 2DUS, 3DUS, and MRI (areas under the curve, 0.86, 0.915, and 0.935, respectively) with a statistically significant difference between 2DUS and MRI (P = .0103), even when the 95% confidence interval showed an overlap. Other posterior deep infiltrating endometriosis was identified by 2DUS in 55 of 75 patients, by 3DUS in 65 of 75, and by MRI in 66 of 75. A receiver operating characteristic curve analysis showed very good results for 2DUS, 3DUS, and MRI (areas under the curve, 0.801, 0.838, and 0.857) with no statistically significant differences. In the 12 women with deep infiltrating endometriosis in the anterior location, the nodules were correctly identified by 2DUS in 3 of 12 patients, by 3DUS in 5 of 12, and by MRI in 6 of 12.

CONCLUSIONS

Our results seem to suggest that there is a statistically significant difference between 2DUS and MRI for the intestinal location of deep infiltrating endometriosis, whereas no differences were found among the techniques for the other locations.

Imaging modalities for the non-invasive diagnosis of endometriosis

BACKGROUND

About 10% of women of reproductive age suffer from endometriosis. Endometriosis is a costly chronic disease that causes pelvic pain and subfertility. Laparoscopy, the gold standard diagnostic test for endometriosis, is expensive and carries surgical risks. Currently, no non-invasive tests that can be used to accurately diagnose endometriosis are available in clinical practice. This is the first review of diagnostic test accuracy of imaging tests for endometriosis that uses Cochrane methods to provide an update on the rapidly expanding literature in this field.

OBJECTIVES

• To provide estimates of the diagnostic accuracy of imaging modalities for the diagnosis of pelvic endometriosis, ovarian endometriosis and deeply infiltrating endometriosis (DIE) versus surgical diagnosis as a reference standard.• To describe performance of imaging tests for mapping of deep endometriotic lesions in the pelvis at specific anatomical sites.Imaging tests were evaluated as replacement tests for diagnostic surgery and as triage tests that would assist decision making regarding diagnostic surgery for endometriosis.

SEARCH METHODS

We searched the following databases to 20 April 2015: MEDLINE, CENTRAL, EMBASE, CINAHL, PsycINFO, Web of Science, LILACS, OAIster, TRIP, ClinicalTrials.gov, MEDION, DARE, and PubMed. Searches were not restricted to a particular study design or language nor to specific publication dates. The search strategy incorporated words in the title, abstracts, text words across the record and medical subject headings (MeSH).

SELECTION CRITERIA

We considered published peer-reviewed cross-sectional studies and randomised controlled trials of any size that included prospectively recruited women of reproductive age suspected of having one or more of the following target conditions: endometrioma, pelvic endometriosis, DIE or endometriotic lesions at specific intrapelvic anatomical locations. We included studies that compared the diagnostic test accuracy of one or more imaging modalities versus findings of surgical visualisation of endometriotic lesions.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected and performed a quality assessment of data from each study. For each imaging test, data were classified as positive or negative for surgical detection of endometriosis, and sensitivity and specificity estimates were calculated. If two or more tests were evaluated in the same cohort, each was considered as a separate data set. We used the bivariate model to obtain pooled estimates of sensitivity and specificity when sufficient data sets were available. Predetermined criteria for a clinically useful imaging test to replace diagnostic surgery included sensitivity ≥ 94% and specificity ≥ 79%. Criteria for triage tests were set at sensitivity ≥ 95% and specificity ≥ 50%, ruling out the diagnosis with a negative result (SnNout test - if sensitivity is high, a negative test rules out pathology) or at sensitivity ≥ 50% with specificity ≥ 95%, ruling in the diagnosis with a positive result (SpPin test - if specificity is high, a positive test rules in pathology).

MAIN RESULTS

We included 49 studies involving 4807 women: 13 studies evaluated pelvic endometriosis, 10 endometriomas and 15 DIE, and 33 studies addressed endometriosis at specific anatomical sites. Most studies were of poor methodological quality. The most studied modalities were transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI), with outcome measures commonly demonstrating diversity in diagnostic estimates; however, sources of heterogeneity could not be reliably determined. No imaging test met the criteria for a replacement or triage test for detecting pelvic endometriosis, albeit TVUS approached the criteria for a SpPin triage test. For endometrioma, TVUS (eight studies, 765 participants; sensitivity 0.93 (95% confidence interval (CI) 0.87, 0.99), specificity 0.96 (95% CI 0.92, 0.99)) qualified as a SpPin triage test and approached the criteria for a replacement and SnNout triage test, whereas MRI (three studies, 179 participants; sensitivity 0.95 (95% CI 0.90, 1.00), specificity 0.91 (95% CI 0.86, 0.97)) met the criteria for a replacement and SnNout triage test and approached the criteria for a SpPin test. For DIE, TVUS (nine studies, 12 data sets, 934 participants; sensitivity 0.79 (95% CI 0.69, 0.89) and specificity 0.94 (95% CI 0.88, 1.00)) approached the criteria for a SpPin triage test, and MRI (six studies, seven data sets, 266 participants; sensitivity 0.94 (95% CI 0.90, 0.97), specificity 0.77 (95% CI 0.44, 1.00)) approached the criteria for a replacement and SnNout triage test. Other imaging tests assessed in small individual studies could not be statistically evaluated.TVUS met the criteria for a SpPin triage test in mapping DIE to uterosacral ligaments, rectovaginal septum, vaginal wall, pouch of Douglas (POD) and rectosigmoid. MRI met the criteria for a SpPin triage test for POD and vaginal and rectosigmoid endometriosis. Transrectal ultrasonography (TRUS) might qualify as a SpPin triage test for rectosigmoid involvement but could not be adequately assessed for other anatomical sites because heterogeneous data were scant. Multi-detector computerised tomography enema (MDCT-e) displayed the highest diagnostic performance for rectosigmoid and other bowel endometriosis and met the criteria for both SpPin and SnNout triage tests, but studies were too few to provide meaningful results.Diagnostic accuracies were higher for TVUS with bowel preparation (TVUS-BP) and rectal water contrast (RWC-TVS) and for 3.0TMRI than for conventional methods, although the paucity of studies precluded statistical evaluation.

AUTHORS' CONCLUSIONS

None of the evaluated imaging modalities were able to detect overall pelvic endometriosis with enough accuracy that they would be suggested to replace surgery. Specifically for endometrioma, TVUS qualified as a SpPin triage test. MRI displayed sufficient accuracy to suggest utility as a replacement test, but the data were too scant to permit meaningful conclusions. TVUS could be used clinically to identify additional anatomical sites of DIE compared with MRI, thus facilitating preoperative planning. Rectosigmoid endometriosis was the only site that could be accurately mapped by using TVUS, TRUS, MRI or MDCT-e. Studies evaluating recent advances in imaging modalities such as TVUS-BP, RWC-TVS, 3.0TMRI and MDCT-e were observed to have high diagnostic accuracies but were too few to allow prudent evaluation of their diagnostic role. In view of the low quality of most of the included studies, the findings of this review should be interpreted with caution. Future well-designed diagnostic studies undertaken to compare imaging tests for diagnostic test accuracy and costs are recommended.

Fusion imaging for evaluation of deep infiltrating endometriosis: feasibility and preliminary results

OBJECTIVE

Magnetic resonance imaging (MRI) and ultrasound scanning complement each other in screening for and diagnosis of endometriosis. Fusion imaging, also known as real-time virtual sonography, is a new technique that uses magnetic navigation and computer software for the synchronized display of real-time ultrasound and multiplanar reconstructed MR images. Our aim was to evaluate the feasibility and ability of fusion imaging to assess the main anatomical sites of deep infiltrating endometriosis (DIE) in patients with suspected active endometriosis.

METHODS

This prospective study was conducted over a 1-month period in patients referred to a trained radiologist for an ultrasound-based evaluation for endometriosis. Patients with a prior pelvic MRI examination within the past year were offered fusion imaging, in addition to the standard evaluation. All MRI examinations were performed on a 1.5-T MRI machine equipped with a body phased-array coil. The MRI protocol included acquisition of at least two fast spin-echo T2-weighted orthogonal planes. The Digital Imaging Communications in Medicine dataset acquired at the time of the MRI examination was loaded into the fusion system and displayed together with the ultrasound image on the same monitor. The sets of images were then synchronized manually using one plane and one anatomical reference point. The ability of this combined image to identify and assess the main anatomical sites of pelvic endometriosis (uterosacral ligaments, posterior vaginal fornix, rectum, ureters and bladder) was evaluated and compared with that of standard B-mode ultrasound and MRI.

RESULTS

Over the study period, 100 patients were referred for ultrasound examination because of endometriosis. Among them were 20 patients (median age, 35 (range, 27-49) years) who had undergone MRI examination within the past year, with a median (range) time interval between MRI and ultrasound examination of 171 (1-350) days. All 20 patients consented to undergo additional evaluation by fusion imaging. However, in three (15%) cases, fusion imaging was not technically possible because of changes since the initial MRI examination resulting from either interval surgery (n = 2; 10%) or pregnancy (n = 1; 5%). Data acquisition, matching and fusion imaging were performed in under 10 min in each of the other 17 cases. The overall ability of each technique to identify and assess the main anatomical landmarks of endometriosis was as follows: uterosacral ligaments: ultrasound, 88% (30/34); MRI, 100% (34/34); fusion imaging, 100% (34/34); posterior vaginal fornix: ultrasound, 88% (30/34); MRI, 100% (34/34); fusion imaging, 100% (34/34); rectum: ultrasound, 100% (17/17); MRI, 82.3% (14/17); fusion imaging, 100% (17/17); ureters: ultrasound, 0%; MRI, 100% (34/34); fusion imaging, 100% (34/34); and bladder: ultrasound, 100%; MRI, 100%; fusion imaging, 100%.

CONCLUSION

Fusion imaging is feasible for the assessment of endometriotic lesions. Because it combines information from both ultrasound and MRI techniques, fusion imaging allows better identification of the main anatomical sites of DIE and has the potential to improve the performance of ultrasound and MRI examination.

Endometriosis: the role of magnetic resonance imaging

Several imaging options are available today to diagnose endometriosis. Currently, the two techniques most used are sonography and magnetic resonance imaging (MRI). Three-dimensional (3D) sonography has proved to be particularly sensitive in the diagnosis of endometriosis. In recent years, MRI has emerged as a high reproducible method to explore endometriosis; moreover, its capability to evaluate tissue signal is an extremely powerful system in the differential diagnosis with other pathologies and for the identification of malignant degeneration. The purpose of this paper is to present the state-of-the-art of MRI of endometriosis by performing a review of the literature and showing the epidemiology, pathogenesis, and classification of endometriosis. In this work, the technique that should be used, MR findings of endometriosis and the principles of differential diagnosis are explained.

The importance and perspective of magnetic resonance imaging in the evaluation of endometriosis

MR imaging is becoming increasingly important in the assessment of patients with endometriosis. Its multiplanar capabilities and superior soft tissue contrast are particularly useful in the detection of deep infiltrating endometriotic implants. Endometriosis, defined as the presence of endometrial glands and stroma outside the endometrium, is among the most common gynaecological disorders affecting women in their reproductive age. The diagnosis and evaluation of the extension of endometriosis are difficult only with physical examination and laparoscopy. According to the authors' personal experience, a special MRI technique and some imaging guidelines regarding different anatomical localizations of endometriosis are discussed. This review is a brief presentation of current evidence on the diagnostic accuracy of MRI in the evaluation of endometriosis concerning other diagnostic methods, the limitations of MRI and its essential usefulness for preoperative diagnosis of deep pelvic endometriosis, and future perspectives in monitoring this disease.