Postoperative imaging findings after laparoscopic surgery for deeply infiltrating endometriosis

Postoperative Imaging of Endometriosis

Endometriosis is a highly prevalent disease that affects 10%-15% of women of reproductive age worldwide and is mainly associated with chronic pelvic pain and infertility. With the widespread use of imaging for the diagnosis and monitoring of endometriosis, combined with the ability of surgery to eradicate the disease and address infertility, there has been a significant increase in recent years in imaging examinations for postoperative evaluation of endometriosis. US and MRI are used not only to help diagnose and map endometriosis but also to evaluate refractory symptoms, residual lesions, and complications at posttreatment assessment. Knowledge of surgical techniques and recognition of expected postoperative imaging findings are crucial to differentiate postoperative changes from residual disease and/or recurrence. The authors discuss imaging aspects of postoperative endometriosis, with an emphasis on the imaging approach, comprehension of surgical techniques, recognition of the expected findings, possible complications, and analysis of residual disease or recurrence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by VanBuren in this issue. The slide presentation from the RSNA Annual Meeting is available for this article.

MRI and rectal endoscopy sonography performance to diagnose the digestive depth infiltration of pelvic endometriosis

INTRODUCTION

The main objective of this study was to evaluate the performances of MRI and rectal endoscopy sonography (RES) in predicting the depth of bowel wall infiltration by deep infiltrating endometriosis (DIE).

MATERIAL AND METHOD

We conducted a single center retrospective study from April 2014 to March 2020 including all patients who had undergone digestive tract resection (discoid or segmental) for DIE removal and who had benefited from full preoperative imaging workup based on both pelvic MRI and RES.

RESULTS

Fifty two patients were enrolled in the study. Median age was 35.8 years (26.1-44.5 years). Indications for surgery mainly comprised chronic pelvic pain (94.2%) and infertility (36.5%). Overall, pathological examination showed digestive involvement in 92.3% of patients, while transmural infiltration was found in 38.4% of cases. In contrast, both MRI and RES suspected transmural involvement in 42 patients (80.8%). Corresponding sensitivity and specificity were 0.95 [95% CI (0.751-0.999)] and 0.28 [95% CI (0.137-0.467)], respectively. Our results revealed agreement between MRI and RES in 85% of cases with a kappa at 0.5 [95% CI (0.207-0.803), moderate agreement]. Subgroup analysis in patients with transmural MRI lesions showed a sensitivity of 0.95 [95% CI (0.740-0.999)] and a specificity of 0.13 [95% CI (0.028-0.336)].

CONCLUSION

Our study suggests that performing a second-line examination is not useful if there is no transmural impairment in MRI or RES. Nevertheless, the combination of these two preoperative examinations seems to be essential for the evaluation of the depth of digestive involvement of endometriosis to guide surgical management as effectively as possible. The constitution and training of multidisciplinary expert groups must be developed to be able to offer optimal patient management.

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.

MRI sliding sign: Using MRI to assess rectouterine mobility in pelvic endometriosis

INTRODUCTION

Surgical excision of deep infiltrating endometriosis (DIE) is complex and associated with morbidity. Diagnostic imaging plays an important role in the preoperative workup. We sought to determine the utility of single sagittal T2-weighted MRI motion sequence in the preoperative assessment of pelvic mobility in patients with endometriosis.

METHODS

An observational study at a single tertiary public referral centre in Australia. Eighty-one MRI studies from 1 May 2019 to 3 December 2019, were enrolled. Studies were included if they were performed to stage endometriosis, including a T2-weighted motion series, adequately covering a uterus, cervix and rectum. Fifty-seven studies met inclusion criteria. The reference standard was a contemporaneous transvaginal ultrasound (TVUS) reporting on pelvic organ mobility. Three subspecialist radiologists were then blindly asked to identify, on the cine loop: rectouterine immobility, superficial endometriosis (pelvic bowel adhesions), rectosigmoid Deep Infiltrating Endometriosis (DIE). Fleiss' Kappa assessed interobserver agreement. Consensus MRI sensitivity and specificity were estimated against the reference standard (TVUS).

RESULTS

Median age was 35 years (range 19-51). Forty-three cases had a contemporaneous TVUS; 14 reporting a sliding sign, 29 with fixed pelves. Interobserver agreement was 'substantial' (k = 0.79) for absent MRI sliding sign and 'almost perfect' (k = 0.90) for absence of DIE. Consensus MRI had 90% sensitivity (95% CI 73-98%) for pelvic immobility at TVUS (absent sliding sign). Interobserver agreement and consensus MRI sensitivity were higher for adhesions and immobility than normal findings.

CONCLUSION

An MRI motion sequence can identify patients with pelvic adhesions and immobility, helping determine surgical difficulty when TVUS is not diagnostic.