MRI and "tenderness guided" transvaginal ultrasonography in the diagnosis of recto-sigmoid endometriosis

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.

Advances in Imaging for Assessing Pelvic Endometriosis

In recent years, due to the development of standardized diagnostic protocols associated with an improvement in the associated technology, the diagnosis of pelvic endometriosis using imaging is becoming a reality. In particular, transvaginal ultrasound and magnetic resonance are today the two imaging techniques that can accurately identify the majority of the phenotypes of endometriosis. This review focuses not only on these most common imaging modalities but also on some additional radiological techniques that were proposed for rectosigmoid colon endometriosis, such as double-contrast barium enema, rectal endoscopic ultrasonography, multidetector computed tomography enema, computed tomography colonography and positron emission tomography-computed tomography with 16α-[18F]fluoro-17β-estradiol.

Diagnosis of presence and extent of deep infiltrating endometriosis by preoperative MRI-improvement of staging accuracy by expert training

INTRODUCTION

This study evaluates the clinical utility of magnetic resonance imaging (MRI) for the determination of presence and extent of DIE with special emphasis on effects of MRI reporting training MATERIAL AND METHODS: Data from 80 patients with clinically suspected DIE presented at our certified endometriosis center between 2015 and 2018 were analyzed. For all patients an ENZIAN score (describing DIE related to individual anatomical localizations) was obtained based on the preoperative MRI findings. The intraoperatively determined ENZIAN score served as the reference for assessment of diagnostic performance of the MRI.

RESULTS

Overall, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of DIE by MRI were 76.9%, 53.3%, 87.7% and 34.8%, respectively. Analysis by compartment revealed a sensitivity, specificity, PPV and NPV of 59.5%, 88.2%, 86.2% and 63.9%, respectively, for compartment A, with similar values for compartment B, and 50.0%, 88.9%, 64.7% and 81.4%, respectively, for the less often affected compartment C. Expert training (n = 32 before, n = 48 after) led to a considerable increase in sensitivities for the overall detection of DIE (84.6% vs. 65.4%, p = 0.071) and for the detection of DIE in compartment A (71.4% vs. 35.7%, p = 0.026), compartment B (66.7% vs. 37.5%, p = 0.057) and compartment C (75.0% vs. 20.0%, p = 0.010), without significant loss in specificity (all p > 0.50).

DISCUSSION

After expert training, MRI has a good sensitivity with fair specificity regarding preoperative assessment of presence, location and extent of DIE.

Magnetic Resonance Imaging in the Evaluation of Female Infertility

Pelvic MRI plays an important adjunctive role in the clinical workup of female infertility. Hysterosalpingography is the first line imaging modality in evaluation of female infertility, and hysterosalpingo-contrast sonography can also be used to evaluate both the uterine cavity and fallopian tubes. Pelvic MRI can be helpful in the workup of female infertility, particularly in cases of Mullerian duct anomalies, fibroids, adenomyosis, endometriosis, and tubal disease. These conditions and their appearance on imaging will be reviewed in this article.

Current Status of Transvaginal Ultrasound Accuracy in the Diagnosis of Deep Infiltrating Endometriosis Before Surgery: A Systematic Review of the Literature

Endometriosis is a common gynecologic condition affecting as many as 1 per 10 women. Transvaginal ultrasound (TVUS) has become a frontline tool in the diagnosis of deep infiltrating endometriosis (DIE) before surgery. The primary aim of this review was to determine the accuracy of TVUS for DIE. The secondary aim was to determine accuracy specifically when a sonographer performed the TVUS examination. A systematic review was performed, searching literature by following a population, intervention, comparator, and outcome outline. MEDLINE, Embase, Emcare, and Google Scholar were searched in July 2018 and in November 2019. Including "sonographer" in the search terms yielded no results, so our terms were expanded. Two hundred and four articles were returned from the searches, and 35 were ultimately included in the final review. Analysis of the returned articles revealed the TVUS is a valuable diagnostic tool for DIE before surgery. Sensitivities ranged from 78.5% to 85.3%, specificities from 46.1% to 92.5%, and accuracies from 75.7% to 97%. Most authors reported site-specific sensitivities and specificities, which varied greatly between locations. Site-specific sensitivities ranged from 10% to 88.9% (uterosacral ligaments), 20% to 100% (bladder), 33.3% to 98.1% (rectosigmoid colon), and 31% to 98.7% (pouch of Douglas). Site-specific specificities ranged from 75% to 99.6% (uterosacral ligaments), 96.4% to 100% (bladder), 86% to 100% (rectosigmoid colon), and 90% to 100% (pouch of Douglas). Transvaginal ultrasound is an accurate tool in the diagnosis of DIE; however, limited data exist as to whether this technique is accurate when performed by sonographers. More evidence surrounding the reliability between operators is also needed.

Recommendations for MRI technique in the evaluation of pelvic endometriosis: consensus statement from the Society of Abdominal Radiology endometriosis disease-focused panel

Endometriosis is a common entity causing chronic pain and infertility in women. The gold standard method for diagnosis is diagnostic laparoscopy, which is invasive and costly. MRI has shown promise in its ability to diagnose endometriosis and its efficacy for preoperative planning. The Society of Abdominal Radiology established a Disease-Focused Panel (DFP) to improve patient care for patients with endometriosis. In this article, the DFP performs a literature review and uses its own experience to provide technical recommendations on optimizing MRI Pelvis for the evaluation of endometriosis.

ACR Appropriateness Criteria® Female Infertility

The most common known causes of female infertility are male factor (26%), ovulatory failure (21%), and tubal damage (14%), while in 28% a couple's infertility remains unexplained. Female-specific causes of infertility include deterioration of oocyte quality with increasing maternal age; ovulatory disorders, most notably polycystic ovarian syndrome; history of salpingitis such as that caused by chlamydia infection; endometriosis; and uterine cavity abnormalities interfering with implantation causing inability to become pregnant or causing recurrent pregnancy loss. These potential causes of female infertility are discussed in this document and the appropriate imaging recommendations for each variant are provided. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Sliding Sign and Gel Sonovaginography: A Sneak Peek Prior to Laparoscopy in Patients with Endometriosis

Context:

The rising incidence of endometriosis may be due to improvisation in the diagnostic techniques. Transvaginal sonography has proven to be very useful in the diagnosis of complexity of the disease and in turn to predict the intraoperative findings on laparoscopy.

Aims:

The aim was to study the use of sliding sign for detecting the status of the pouch of Douglas (POD) and to check for the presence of bowel and nonbowel deep infiltrating endometriosis (DIE) by gel sonovaginography.

Settings and Design:

This is a prospective observational study carried out patient division of Department of OBG in Kasturba Hospital Manipal.

Methods:

The study was carried out over a period of 2 years and included 136 women. After written informed consent, a detailed history and clinical examination was done. A detailed transvaginal sonography was done for each of the patients by a single observer on the Philips HD11XE machine two-dimensional transvaginal probe which included gel sonovaginography and real-time dynamic test called sliding sign.

Statistical Analysis:

Chi-square test was used in this study.

Results:

Sliding sign is highly specific, sensitive, and accurate for the detection of POD obliteration. It is 96.6% sensitive and 89.5% specific. It is 94.1% accurate and 94.5% positively predictive for the same. Transvaginal sonography is >92% specific for the detection of bowel and nonbowel DIE. The accuracy is over 91%. The negative predictability is 93.6% and 94.6%, respectively.

Conclusions:

Sliding sign is a useful, easy-to-perform, reproducible, and noninvasive modality for assessing the status of POD. Gel sonovaginography is also useful in accurately detecting the presence of deep infiltrating endometriotic deposits.

Diagnostic Performances of Tridimensional Rectosonography and Magnetic Resonance Imaging in Rectosigmoid Endometriosis: A Prospective Cohort Study on 101 Patients

Tridimensional rectosonography (3-D RSG) is a transvaginal ultrasonography procedure combining intrarectal contrast with tridimensional technology. The objectives of this study were to assess the diagnostic performances of 3-D RSG in deep infiltrating rectosigmoid endometriosis using surgery and pathology as the gold standard, and to compare its results with those of magnetic resonance imaging (MRI). Patients referred for endometriosis with symptoms suggesting deep infiltrating intestinal endometriosis (DIE) were included if they agreed to undergo a 3-D RSG and MRI and if there was a surgical indication related to endometriosis. The study was a non-randomized monocentric prospective cohort study (Canadian task force classification Level II-2). From May 2012 to May 2017, 101 patients were included. Sixty patients (59.4%) had bowel involvement of the rectum (n = 21, 20.8%) or of the sigmoid (n = 39, 38.6%) confirmed in surgery and/or in pathologic testing. In the diagnosis of rectosigmoid DIE, 3-D RSG sensitivity, specificity, positive predictive value, negative predictive value, accuracy and κ index were 93%, 95%, 97%, 91%, 94% and 0.88, respectively. For MRI they were 87%, 90%, 93%, 82%, 88% and 0.76, respectively. The accuracy was not significantly different between 3-D RSG and MRI (p = 0.181). In conclusion, 3-D RSG is an effective technique to diagnose rectosigmoid endometriosis and seems to have similar diagnostic performances to MRI for this indication.

Imaging Modalities for Diagnosis of Deep Pelvic Endometriosis: Comparison between Trans-Vaginal Sonography, Rectal Endoscopy Sonography and Magnetic Resonance Imaging. A Head-to-Head Meta-Analysis

OBJECTIVES

A meta-analysis, with a head-to-head approach, was carried out to compare the three most common techniques for a deep pelvic endometriosis (DPE) diagnosis. We focused on: transvaginal-sonography (TVS), magnetic-resonance imaging (MRI), and rectal-endoscopy-sonography (RES).

METHODS

Electronic databases were searched from their inception until December 2018. All prospective and well-defined retrospective studies carried out in tertiary referral centers were considered. This review was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Synthesizing Evidence from Diagnostic Accuracy Tests (SEDATE) guidelines. We considered only papers in which at least two imaging modalities were compared in the same set of patients (head-to-head approach). Meta-analysis of diagnostic test accuracy (DTA) was performed separately for each location of interest. Bivariate or univariate approach has been applied when appropriate. We analyze the DTA of TVS vs. MRI, TVS vs. RES, and MRI vs. RES.

RESULTS

Our meta-analysis (17 studies included) showed high-to-moderate DTA of TVS for all endometriosis locations (apart from recto-vaginal septum (RVS)) that were not statistically different from MRI and RES for those localized in the posterior compartment. RES results were more accurate than MRI for RS lesions but less accurate than TVS for other pelvic locations, except for RVS.

CONCLUSIONS

All approaches provide good accuracy with specific strong points. Ultrasonography demonstrated a diagnostic accuracy not inferior to MRI and RES; therefore, it must be considered the primary approach for DPE diagnosis. MRI has to be considered as a valuable approach in settings where highly skilled sonographers are not available. Keypoints: (1) We confirmed the non-inferiority of TVS compared to MRI and RES for the diagnosis of specific pelvic anatomic location of endometriosis lesions. (2) Ultrasonography could be considered the primary approach for DPE diagnosis (less invasive than RES and less expensive than MRI). (3) MRI has to be considered as a valuable approach in settings where skilled sonographers are not available.

Post-operative complications and recurrence rate after treatment of bowel endometriosis: Comparison of three techniques

Objective

The aim of the present study was to compare post-operative complications and recurrence of three surgical techniques: segmental resection, discoid excision and nodule shaving.

Study design

From January 2014 to December 2017, 143 patients who underwent segmental bowel resections for endometriosis at “La Paz” University Hospital, were enrolled and grouped by different techniques. We compared post-operative complications and recurrence rate in three groups: 76 (53%) patients underwent segmental resection (group I), 20 (14%) patients underwent discoid resection (group II) and 47 (33%) patients underwent rectal shaving (group III).

Qualitative data was defined by absolute values and percentages, and quantitative data by mean and standard deviation. Qualitative variables between groups were compared using Chi- squared test. While quantitative data between groups was performed by means of t-test and ANOVA test. For all statistical tests a value of p < 0.05 will be considered statistically significant.

Result

Segmental resection was associated with higher rate of severe post-operative complications in comparison with discoid resection or shaving technique (23.5% versus 5% versus 0% respectively) (p = 0.005). We showed statistical differences among the three study groups for nodule size (p < 0.001) and localization (p = 0.02). Our analysis showed statistical differences among the three groups in term of additional procedures performed at the same time of bowel surgery, in particular in case of endometriosis of the ureter (p = 0.001) and the parametrium (p = 0.04).

After a long follow-up (46.4 ± 0.5 months for the group I, 42.2 ± 1.6 months for the group II, 39.7 ± 1.8 months for the group III), the shaving group was associated to higher recurrence rate (12.7%) in comparison with the discoid group (5%) and the segmental resection group (1.3%) (p = 0.01).

Conclusion

We showed that segmental resection is associated with high rate of postoperative complications. Conversely, this strategy should avoid the need of further interventions in young patients. Conservative surgery, such as discoid resection and shaving, revealed a higher recurrence rate and could be more appropriate in women approximating menopause because of the lower possibility of recurrence.

Accuracy of transvaginal sonography versus magnetic resonance imaging in the diagnosis of rectosigmoid endometriosis: Systematic review and meta-analysis

INTRODUCTION

Intestinal endometriosis is considered the most severe form of deep endometriosis, the rectosigmoid being involved in about 90% of cases of bowel infiltration. Transvaginal sonography (TVS) and magnetic resonance imaging (MRI) have been used for noninvasive diagnosis and preoperative mapping of rectosigmoid endometriosis (RE), but no consensus has been reached so far regarding which method is the most accurate in this setting.

OBJECTIVE

We aimed at performing a systematic review and meta-analysis to compare the accuracy of TVS versus MRI in the diagnosis of RE in a same population.

METHODS

A systematic review was conducted in accordance with the PRISMA guidelines. Studies were identified by searching the MEDLINE, Embase, and LILACS databases, as well the reference lists of retrieved articles, through February 2019. We included all cross-sectional studies that evaluated the accuracy of TVS versus MRI in the diagnosis of RE within a same sample of subjects and that used surgical findings with histological confirmation as the gold standard. The QUADAS-2 instrument was used to evaluate study quality. Sensitivity, specificity, positive likelihood ratios (LR+), and negative likelihood ratios (LR-) for the diagnosis of RE were calculated. This study is registered with PROSPERO, number CRD42017064378.

RESULTS

Eight studies (n = 1132) were included in the meta-analysis. The pooled sensitivity, specificity, LR+, and LR- values of MRI for RE were 90% (95% CI, 87-92%), 96% (95% CI, 94-97%), 17.26 (95% CI, 3.57-83.50), and 0.15 (95% CI, 0.10-0.23); values of TVS were 90% [95% CI, 87-92%], 96% (95% CI, 94-97%), 20.66 (95% CI, 8.71-49.00) and 0.12 (95% CI, 0.08-0.20), respectively. Areas under the S-ROC curves (AUC) showed no statistically significant differences between MRI (AUC = 0.948) and TVS (AUC = 0.930) in the diagnosis of RE (P = 0.13). Moreover, considering the average prevalence among the studies of 47.3%, both methods demonstrated similarly high positive post-test probabilities (93.9% for TVS and 94.8% for MRI), and the combined use of them yielded a post-test probability of 99.6%.

CONCLUSION

MRI and TVS have similarly high accuracy and positive post-test probabilities in the noninvasive diagnosis of RE. Combination of MRI and TVS may increase even further the positive post-test probabilities to near 100%.

ENDORECT: a preoperative score to accurately predict rectosigmoid involvement in patients with endometriosis

Study question

Could we construct and validate a preoperative score to predict rectosigmoid involvement in endometriosis (RE)?

Summary answer

We developed a simple preoperative score (ENDORECT) to predict RE.

What is known already

Accurate preoperative classification is important to optimize the surgical approach for patients with endometriosis but there is currently no reliable first-line examination to determine RE.

Study design size duration

This was a single-centre observational study including all women (N = 119) who underwent complete surgery for endometriosis between January 2011 and June 2016 in the Gynaecological Department of the University Hospital of Poissy Saint-Germain en Laye.

Participants/materials setting methods

Of the 119 women, 47 had RE and 72 did not. Two-thirds of the patients were randomly selected to derive the predictive score based on multiple logistic regression with internal validation by bootstrap. We used information from a self-assessment questionnaire, digital and speculum examination, transvaginal ultrasound and MRI. The score was then applied to the remaining sample of patients for validation.

Main results and the role of chance

Four variables were independently associated with RE: palpation of a posterior nodule on digital examination (aOR=5.6; 95%CI [1.7-21.8]); a UBESS score of 3 on ultrasonography (aOR=4.9; 95%CI [1.4-19.8); RE infiltration on MRI (aOR=6.8; 95%CI [2-25.5]); and presence of blood in the stools during menstruation (aOR=5.2; 95%CI [1.3-24.7]). The ROC-AUC of the model was 0.86 (95%CI [0.77-0.94]) and the bootstrap procedure showed that the model was stable. The ENDORECT score was derived from these four criteria and three risk groups were identified: the high-risk group (score>17) had a probability of RE of 100% with an specificity (Sp) of 100%, postive likelihood ratio (Lr+)>10; the intermediate-risk group (score: 7-17) had a probability of RE of 42%; and the low-risk group (score=0), with a sensitivity (Se) of 97%, negative likelihood ratio (Lr-) of 0.07 and a probability of RE of 5%. In the validation cohort, a score >17 predicted RE with an Sp of 96, Lr+ of 9.2, and probability of RE of 83%. Patients in this sample with a score=0, had an Se of 100%, Lr- of 0 and a probability of RE of 0%.

Limitations reasons for caution

The single-centre recruitment and over-representation of RE could constitute a referral bias.

Wider implications of the findings

The use of a preoperative predictive score could facilitate patient counselling and guide surgical management. Both MRI and transvaginal ultrasound provide independent information and are useful before surgery for RE.

Study funding/competing interests

No financial support was specifically received for this study. The authors declare no conflict of interest.

Trial registration number

N/A.

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.

Transvaginal ultrasound vs magnetic resonance imaging for diagnosing deep infiltrating endometriosis: systematic review and meta-analysis

OBJECTIVE

To perform a systematic review of studies comparing the accuracy of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) in diagnosing deep infiltrating endometriosis (DIE) including only studies in which patients underwent both techniques.

METHODS

An extensive search was carried out in PubMed/MEDLINE and Web of Science for papers from January 1989 to October 2016 comparing TVS and MRI in DIE. Studies were considered eligible for inclusion if they reported on the use of TVS and MRI in the same set of patients for the preoperative detection of endometriosis in pelvic locations in women with clinical suspicion of DIE and using surgical data as a reference standard. Quality was assessed using the QUADAS-2 tool. A random-effects model was used to determine pooled sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-) and diagnostic odds ratio (DOR).

RESULTS

Of 375 citations identified, six studies (n = 424) were considered eligible. For MRI in the detection of DIE in the rectosigmoid, pooled sensitivity was 0.85 (95% CI, 0.78-0.90), specificity was 0.95 (95% CI, 0.83-0.99), LR+ was 18.4 (95% CI, 4.7-72.4), LR- was 0.16 (95% CI, 0.11-0.24) and DOR was 116 (95% CI, 23-585). For TVS in the detection of DIE in the rectosigmoid, pooled sensitivity was 0.85 (95% CI, 0.68-0.94), specificity was 0.96 (95% CI, 0.85-0.99), LR+ was 20.4 (95% CI, 4.7-88.5), LR- was 0.16 (95% CI, 0.07-0.38) and DOR was 127 (95% CI, 14-1126). For MRI in the detection of DIE in the rectovaginal septum, pooled sensitivity was 0.66 (95% CI, 0.51-0.79), specificity was 0.97 (95% CI, 0.89-0.99), LR+ was 22.5 (95% CI, 6.7-76.2), LR- was 0.38 (95% CI, 0.23-0.52) and DOR was 65 (95% CI, 21-204). For TVS in the detection of DIE in the rectovaginal septum, pooled sensitivity was 0.59 (95% CI, 0.26-0.86), specificity was 0.97 (95% CI, 0.94-0.99), LR+ was 23.5 (95% CI, 9.1-60.5), LR- was 0.42 (95% CI, 0.18-0.97) and DOR was 56 (95% CI, 11-275). For MRI in the detection of DIE in the uterosacral ligaments, pooled sensitivity was 0.70 (95% CI, 0.55-0.82), specificity was 0.93 (95% CI, 0.87-0.97), LR+ was 10.4 (95% CI, 5.1-21.2), LR- was 0.32 (95% CI, 0.20-0.51) and DOR was 32 (95% CI, 12-85). For TVS in the detection of DIE in the uterosacral ligaments, pooled sensitivity was 0.67 (95% CI, 0.55-0.77), specificity was 0.86 (95% CI, 0.73-0.93), LR+ was 4.8 (95% CI, 2.6-9.0), LR- was 0.38 (95% CI, 0.29-0.50) and DOR was 12 (95% CI, 7-24). Confidence intervals of pooled sensitivities, specificities and DOR were wide for both techniques in all the locations considered. Heterogeneity was moderate or high for sensitivity and specificity for both TVS and MRI in most locations assessed. According to QUADAS-2, the quality of the included studies was considered good for most domains.

CONCLUSION

The diagnostic performance of TVS and MRI is similar for detecting DIE involving rectosigmoid, uterosacral ligaments and rectovaginal septum. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Diagnostic accuracy of magnetic resonance imaging, transvaginal, and transrectal ultrasonography in deep infiltrating endometriosis

To determine the diagnostic accuracy of pelvic magnetic resonance imaging (MRI), transvaginal sonography (TVS), and transrectal sonography (TRS) in diagnosis of deep infiltrating endometriosis (DIE).This diagnostic accuracy study was conducted during a 2-year period including a total number of 317 patients with signs and symptoms of endometriosis. All the patients were evaluated by pelvic MRI, TVS, and TRS in the same center. The criterion standard was considered to be the laparoscopy and histopathologic examination.Of 317 patients being included in the present study, 252 tested positive for DIE. The sensitivity, specificity, positive predictive value, and negative predictive value of TVS was found to be 83.3%, 46.1%, 85.7%, and 41.6%, respectively. These variables were 80.5%, 18.6%, 79.3%, and 19.7% for TRS and 90.4%, 66.1%, 91.2%, and 64.1% for MRI, respectively. MRI had the highest accuracy (85.4%) when compared to TVS (75.7%) and TRS (67.8%). The sensitivity of TRS, TVS, and MRI in uterosacral ligament DIE was 82.8%, 70.9%, and 63.6%, respectively. On the contrary, specificity had a reverse trend, favoring MRI (93.9%, 92.8%, and 89.8% for TVS and TRS, respectively).The results of the present study demonstrated that TVS and TRS have appropriate diagnostic accuracy in diagnosis of DIE comparable to MRI.

[Imaging in the initial and preoperative assessment of endometriosis]

The diagnosis of pelvic endometriosis is based on the combination of clinical examination, endovaginal ultrasonography and pelvic MRI. Ultrasonography displays a moderate sensitivity and a high specificity. Pelvien MRI displays a better sensitivity and lower specificity.

Transvaginal sonography in the diagnosis of deep infiltrating endometriosis: A review

This review summarizes the current evidence regarding the diagnostic accuracy of sonography (US) in women with deep infiltrating endometriosis (DIE). It is well known that transvaginal ultrasound (TVUS) can detect ovarian endometriomas with a high degree of sensitivity. In recent years, US has also been used to detect DIE. In the hands of an experienced sonologist, the sensitivity and specificity of TVUS in the detection of DIE is comparable to those of MRI. TVUS can eliminate the need for an MRI in the majority of patients and reduce the need for diagnostic laparoscopy, proving to be an important tool in preoperative planning. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:313-318, 2017.

[Comparison of the accuracy of rectal endoscopic sonography and magnetic resonance imaging in the diagnosis of colorectal endometriosis]

OBJECTIVE

To compare the accuracy of magnetic resonance imaging (MRI) and rectal endoscopic sonography (RES) for the diagnosis of colorectal endometriosis.

METHODS

In retrospective study, 407 patients operated on service of gynecology of Tenon hospital for deep endometriosis with suspected colorectal involvement. All patients underwent MRI and then RES.

RESULTS

In the study, 239 patients (59%) had colorectal endometriosis which were diagnosed with the histology. The sensitivity, specificity, positive and negative predictive value (PPV and NPV) of RES and MRI for the diagnosis of colorectal endometriosis were respectively 92%, 87%, 91%, 88% and 85%, 88%, 91%, 80%. The accuracy of RES was not significantly different than MRI (90% versus 86%, P=0.09).

CONCLUSION

RES is a good exam to diagnose colorectal endometriosis. It is able to improve diagnosis performances.

Imaging and the Infertility Evaluation

Ultrasound (US) has transformed the fertility evaluation. With 1 consultation, blood work and 1 to 2 USs, the female fertility status can be fully evaluated. The initial US is best done early in the follicular cycle to evaluate the pelvic anatomy and ovarian reserve. A three-dimensional US is important to evaluate for uterine anomalies and color Doppler for any masses. A mid-cycle saline infusion sonohysterogram assesses the endometrial cavity better than a hysterosalpingogram as it identifies the cause of any filling defects. By concurrently adding contrast or agitated saline, tubal patency can be tested. This US-based approach reliably, efficiently, and cost-effectively assesses female infertility.

European society of urogenital radiology (ESUR) guidelines: MR imaging of pelvic endometriosis

Abstract

Endometriosis is a common gynaecological condition of unknown aetiology that primarily affects women of reproductive age. The accepted first-line imaging modality is pelvic ultrasound. However, magnetic resonance imaging (MRI) is increasingly performed as an additional investigation in complex cases and for surgical planning. There is currently no international consensus regarding patient preparation, MRI protocols or reporting criteria. Our aim was to develop clinical guidelines for MRI evaluation of pelvic endometriosis based on literature evidence and consensus expert opinion. This work was performed by a group of radiologists from the European Society of Urogenital Radiology (ESUR), experts in gynaecological imaging and a gynaecologist expert in methodology. The group discussed indications for MRI, technical requirements, patient preparation, MRI protocols and criteria for the diagnosis of pelvic endometriosis on MRI. The expert panel proposed a final recommendation for each criterion using Oxford Centre for Evidence Based Medicine (OCEBM) 2011 levels of evidence.

Key Points

• This report provides guidelines for MRI in endometriosis.

• Minimal and optimal MRI acquisition protocols are provided.

• Recommendations are proposed for patient preparation, best MRI sequences and reporting criteria.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-016-4673-z) contains supplementary material, which is available to authorized users.

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.

Accuracy of transvaginal ultrasound for diagnosis of deep endometriosis in uterosacral ligaments, rectovaginal septum, vagina and bladder: systematic review and meta-analysis

OBJECTIVE

To review the diagnostic accuracy of transvaginal ultrasound (TVS) in the preoperative detection of endometriosis in the uterosacral ligaments (USL), rectovaginal septum (RVS), vagina and bladder in patients with clinical suspicion of deep infiltrating endometriosis (DIE).

METHODS

An extensive search was performed in MEDLINE (PubMed) and EMBASE for studies published between January 1989 and December 2014. Studies were considered eligible if they reported on the use of TVS for the preoperative detection of endometriosis in the USL, RVS, vagina and bladder in women with clinical suspicion of DIE using the surgical data as a reference standard. Study quality was assessed using the PRISMA guidelines and QUADAS-2 tool.

RESULTS

Of the 801 citations identified, 11 studies (n = 1583) were considered eligible and were included in the meta-analysis. For detection of endometriosis in the USL, the overall pooled sensitivity and specificity of TVS were 53% (95%CI, 35-70%) and 93% (95%CI, 83-97%), respectively. The pretest probability of USL endometriosis was 54%, which increased to 90% when suspicion of endometriosis was present after TVS examination. For detection of endometriosis in the RVS, the overall pooled sensitivity and specificity were 49% (95%CI, 36-62%) and 98% (95%CI, 95-99%), respectively. The pretest probability of RVS endometriosis was 24%, which increased to 89% when suspicion of endometriosis was present after TVS examination. For detection of vaginal endometriosis, the overall pooled sensitivity and specificity were 58% (95%CI, 40-74%) and 96% (95%CI, 87-99%), respectively. The pretest probability of vaginal endometriosis was 17%, which increased to 76% when suspicion of endometriosis was present after TVS assessment. Substantial heterogeneity was found for sensitivity and specificity for all these locations. For detection of bladder endometriosis, the overall pooled sensitivity and specificity were 62% (95%CI, 40-80%) and 100% (95%CI, 97-100%), respectively. Moderate heterogeneity was found for sensitivity and specificity for bladder endometriosis. The pretest probability of bladder endometriosis was 5%, which increased to 92% when suspicion of endometriosis was present after TVS assessment.

CONCLUSION

Overall diagnostic performance of TVS for detecting DIE in uterosacral ligaments, rectovaginal septum, vagina and bladder is fair with high specificity.

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.

Consider ultrasound first for imaging the female pelvis

Ultrasound technology has evolved dramatically in recent years and now includes applications such as 3-dimensional volume imaging, real-time evaluation of pelvic organs (simultaneous with the physical examination), and Doppler blood flow mapping without the need for contrast, which makes ultrasound imaging unique for imaging the female pelvis. Among the many cross-sectional imaging techniques, we should use the most informative, less invasive, and less expensive modality to avoid radiation when possible. Hence, ultrasound imaging should be the first imaging modality used in women with pelvic symptoms.

Deep infiltrating endometriosis of the bowel wall: the comet sign

The purpose of this study was to evaluate the appearance of deep infiltrating endometriosis of the bowel wall in the cul-de-sac and determine the characteristic appearance of these lesions. We searched our database between January 1, 2011, and December 31, 2013, for all patients who had sonographic findings of suspected deep infiltrating endometriosis of the bowel with obliteration of the cul-de-sac. The medical record of each patient was examined retrospectively for evidence of surgical confirmation of disease. The sonographic appearance, shape, and size of the bowel wall lesions were evaluated to develop criteria for deep infiltrating endometriosis of the rectosigmoid and cul-de-sac. The search of our database revealed 35 patients with sonographic findings of pelvic bowel wall endometriosis associated with obliteration of the cul-de-sac. Ten of these patients had surgical confirmation of bowel wall endometriosis after the scan, and another 4 patients had surgical evidence of endometriosis from prior surgery. All of the patients who underwent surgery subsequent to sonography had confirmation of their bowel wall infiltrative endometriosis. Sonographically, the bowel lesions were solid, focal, and tubular with slightly irregular margins and in most cases a thinner section or a "tail" at one end, resembling a comet. This study confirms that bowel wall implants have a very characteristic appearance, and extending the transvaginal examination to include an evaluation of the rectosigmoid seeking these bowel lesions is valuable, especially in any patient presenting with a history of pelvic pain.

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.

The 'sliding sign' in conjunction with sonovaginography: is this the optimal approach for the diagnosis of Pouch of Douglas obliteration and posterior compartment deep infiltrating endometriosis?

Introduction: Endometriosis is a chronic peritoneal disease that may progress as a deep infiltrating lesion involving the posterior compartment of the pelvis. Efforts to improve pre-operative knowledge of the location and extent of these lesions have resulted in the development of Transvaginal ultrasound (TVS) as the first-line imaging modality for extra-ovarian endometriosis. However, various techniques of TVS have been described in the literature for this purpose. Methods: In this review we will detail the evolution of TVS as the primary imaging modality in the pre-operative diagnosis of posterior compartment deep infiltrating endometriosis (DIE). We will also discuss the potential of an emerging new real-time diagnostic ultrasound-based technique known as the 'sliding sign' in combination with office gel sonovaginography for the pre-operative diagnosis of Pouch of Douglas obliteration and posterior compartment DIE. Conclusion: Implementation of the new real-time dynamic, reproducible and simple 'sliding sign' in conjunction with SVG has the potential to challenge the current concept that traditional laparoscopy is the 'gold standard' modality for the diagnosis of women with posterior compartment DIE.

Tissue characterization using mean gray value analysis in deep infiltrating endometriosis

OBJECTIVES

To investigate differences in tissue characterization using three-dimensional sonographic mean gray value (MGV) between retrocervical and rectosigmoid deeply infiltrating endometriosis, and to assess intra- and interobserver concordance in MGV quantification.

METHODS

In this retrospective study, stored ultrasound volumes from 50 premenopausal women (mean age, 32 years) with 57 histologically confirmed nodules of deep endometriosis were retrieved from our database for analysis. A single experienced operator had acquired all volumes. For each nodule, the MGV was evaluated using virtual organ computer-aided analysis (VOCAL) software with semiautomated sphere-sampling (1 cm3) from the central part of the nodule. In these patients the MGV was also quantified from the myometrium of the fundal part of the uterus. In addition, two observers calculated the MGV in a subset of 24 volumes in order to quantify inter- and intraobserver agreement using intraclass correlation coefficients (ICC).

RESULTS

Mean MGV was significantly higher in rectosigmoid nodules (n = 34) than in nodules with a retrocervical location (n = 23) (23.863 vs. 17.705; P < 0.001). MGV of the myometrium was significantly higher in comparison with that of nodules in both locations (P < 0.001 for both). Intra- and interobserver measurement reproducibility was excellent (ICC > 0.95).

CONCLUSIONS

Retrocervical and rectosigmoid endometriotic nodules display significantly different MGVs. Measurement of MGV is highly reproducible and its clinical value in the diagnosis and assessment of distribution of deep endometriosis should be assessed in future studies.