Pelvic MRI staging of endometriosis at 3 T without patient preparation or anti-peristaltic: Diagnostic performance outcomes

CAR/CSAR Practice Statement on Pelvic MRI for Endometriosis

The Canadian Association of Radiologists (CAR) Endometriosis Working Group was tasked with providing guidance and benchmarks to ensure the quality of technique and interpretation for advanced imaging modalities associated with diagnosing endometriosis. Advanced pelvic ultrasound is essential in diagnosing and mapping pelvic endometriosis, but pelvic MRI serves as an excellent imaging tool in instances where access to advanced ultrasound is limited, or an alternative imaging modality is required. Despite the known utility of MRI for endometriosis, there is no consensus on imaging protocol and patient preparation in Canada. To improve patient care and support excellence in imaging, the Working Group has developed recommendations for the use of pelvic MRI to assess for endometriosis with an aim to standardize MRI technique for use in both community and academic practices across Canada. The guidelines provide recommendations regarding imaging technique and patient preparation for pelvic MRI, along with suggestions for structured reporting of pelvic MRI for endometriosis.

Best Practices: Ultrasound Versus MRI in the Assessment of Pelvic Endometriosis

Endometriosis is a common yet morbid disease. Imaging plays an important role in diagnosis and treatment planning. Both ultrasound (US) and MRI are used to detect disease. We performed a literature review to assess whether one is superior. A total of 33 studies from the 4482 identified in the initial search were found to assess the efficacy of US and/or MRI in detecting pelvic endometriosis. Most studies were performed at centers with extensive experience with endometriosis, using dedicated US and MRI protocols. A wide range of sensitivities and specificities were reported, but overall weighted means of diagnostic statistics for US and MRI were similar. The choice of dedicated US versus dedicated MRI in the evaluation of endometriosis should therefore be based on the expertise in the region. The data also showed US had better accuracy than MRI for identifying the depth of wall invasion in bowel-wall disease, whereas MRI better depicted pelvic-wall and extraperitoneal disease than US. Routine US and MRI protocols performed worse than dedicated US and MRI protocols, which may account for delays in diagnoses. Clinical and research efforts directed at improving the sensitivity of routine imaging for diagnosing deep endometriosis could improve patient access to appropriate care.

ACR Appropriateness Criteria® Endometriosis

Endometriosis is a common condition impacting individuals assigned female at birth. Though incompletely understood, the disorder is caused by endometrial-like tissue located outside of the endometrial cavity, associated with inflammation and fibrosis. Clinical presentation is variable, ranging from asymptomatic to severe pelvic pain and infertility. Treatment is determined by the patient's individualized goals and can include medical therapies to temporize symptoms or definitive surgical excision. Imaging is used to help diagnose endometriosis and for treatment planning. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

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.

Diagnostic value of susceptibility-weighted imaging for endometrioma: preliminary results from a retrospective analysis

BACKGROUND

Endometrioma is a common manifestation of endometriosis that can be difficult to diagnose with conventional magnetic resonance imaging (MRI). Susceptibility-weighted imaging (SWI) may be more sensitive than conventional MRI in the detection of chronic, local hemorrhagic disease.

PURPOSE

To investigate whether signal voids in SWI sequences could be used in the preoperative diagnosis of endometrioma.

MATERIAL AND METHODS

This retrospective study included consecutive female patients with clinically suspected endometrioma. All patients underwent pelvic 3-T MRI (T1- and T2-weighted) and SWI within two weeks before laparoscopy. Two experienced radiologists blinded to the histopathologic/clinical diagnoses interpreted the images together, and any disagreements were resolved by consensus.

RESULTS

The final analysis included 73 patients: 46 patients (mean age=37 years; age range=22-68 years) with 85 endometrioma lesions and 27 patients (mean age=34 years; age range=15-68 years) with 34 non-endometrioid cystic lesions (18 hemorrhagic corpus luteal cysts, three simple cysts, three mucinous cystadenomas, two mature teratomas, and one endometrioid cyst with corpus luteum rupture/hemorrhage). The presenting symptoms for patients with endometrioma were chronic pelvic pain (44.6%), dysmenorrhea (31.9%), infertility (12.8%), dyspareunia (6.4%), and menstrual irregularity (4.3%). MRI identified all 119 lesions observed laparoscopically. SWI visualized punctate or curvilinear signal voids along the cyst wall or within the lesion in 67 of 85 endometriomas (78.8%) and only 3 of 31 non-endometrioid cysts (8.8%).

CONCLUSION

The use of SWI to look for signal voids in the cyst wall or within the lesion could facilitate the preoperative diagnosis of endometrioma.

Indirect and atypical imaging signals of endometriosis: A wide range of manifestations

Background

Whilst some imaging signs of endometriosis are common and widely accepted as ‘typical’, a range of ‘subtle’ signs could be present in imaging studies, presenting an opportunity to the radiologist and the surgeon to aid the diagnosis and facilitate preoperative surgical planning.

Objective

To summarise and analyse the current information related to indirect and atypical signs of endometriosis by ultrasound (US) and magnetic resonance imaging (MRI).

Methods

Through the use of PubMed and Google scholar, we conducted a comprehensive review of available articles related to the diagnosis of indirect signs in transvaginal US and MRI. All abstracts were assessed and the studies were finally selected by two authors.

Results

Transvaginal US is a real time dynamic exploration, that can reach a sensitivity of 79-94% and specificity of 94%. It allows evaluation of normal sliding between structures in different compartments, searching for adhesions or fibrosis.

MRI is an excellent tool that can reach a sensitivity of 94% and specificity of 77% and allows visualisation of the uterus, bowel loop deviation and peritoneal inclusion cysts. It also allows the categorisation and classification of ovarian cysts, rectovaginal and vesicovaginal septum obliteration, and small bowel endometriotic implants.

Conclusion

The use of an adequate mapping protocol with systematic evaluation and the reporting of direct and indirect signs of endometriosis is crucial for detailed and safe surgical planning.

Abdominal Wall Endometriosis: Two Case Reports and Literature Review

Background and objectives: Abdominal wall endometriosis, also known as scar endometriosis, is a rare condition that is becoming increasingly common. The recent rise in incidence is attributed primarily to the surge of cesarean births, figures that could be influenced in a positive manner considering the improvements brought towards the ultrasound diagnostic methods that have been made in recent years. Materials and Methods: Here we report the cases of two Caucasian women of 38- (G2P2) and 36-years old (G1P1), both subjected to an ultrasound examination due to a specific symptomatic panel reported during anamnesis. Independently of the current status, in the first patient, there were no reported symptom-specific associations with endometriosis, but she had a known history of mild hereditary thrombophilia; the second woman suffered from two conditions positively associated with endometriosis. Results: In both cases, abnormal structures were revealed, with the diagnostic(s) of endometriosis being histologically confirmed based on a set of features observed during the investigation. Conclusions: This paper aims to highlight the importance of reducing cesarean births and to consider the diagnosis of scar endometriosis in women with a history of obstetric or gynaecological surgeries who present with cyclic, recurrent abdominal pain.

MRI for the diagnosis and staging of deeply infiltrating endometriosis: a national survey of BSGE accredited endometriosis centres and review of the literature

OBJECTIVES

Our objective was to establish the primary mode of imaging and MR protocols utilised in the preoperative staging of deeply infiltrating endometriosis in centres accredited by the British Society of Gynaecological Endoscopy (BSGE).

METHODS

The lead consultant radiologist in each centre was invited to complete an online survey detailing their protocols.

RESULTS

Out of 49 centres, 32 (65%) responded to the survey. Two centres performed transvaginal ultrasound as the primary method for preoperative staging of deeply infiltrating endometriosis and the remainder performed MRI. 21/25 centres did not recommend a period of fasting prior to MRI and 22/25 administered hyoscine butylbromide. None of the centres routinely offered bowel preparation or recommended a specific pre-procedure diet. 21/25 centres did not time imaging according to the woman's menstrual cycle, and instructions regarding bladder filling were varied. Rectal and vaginal opacification methods were infrequently utilised. All centres preferentially performed MRI in the supine position - six used an abdominal strap and four could facilitate prone imaging. Just under half of centres used pelvic-phased array coils and three centres used gadolinium contrast agents routinely. All centres performed T1W with fat-suppression and T2W without fat-suppression sequences. There was significant variation relating to other MR sequences depending on the unit.

CONCLUSIONS

There was significant inconsistency between centres in terms of MR protocols, patient preparation and the sequences performed. Many practices were out of line with current published evidence.

ADVANCES IN KNOWLEDGE

Our survey demonstrates a need for evidence-based standardisation of imaging in BSGE accredited endometriosis centres.

Endometriosis MRI lexicon: consensus statement from the society of abdominal radiology endometriosis disease-focused panel

Endometriosis is a common gynecologic disorder characterized by the presence of ectopic endometrial tissue outside the endometrial cavity. Magnetic Resonance Imaging (MRI) has become a mainstay for diagnosis and staging of this disease. In the literature, significant heterogeneity exists in the descriptions of imaging findings and anatomic sites of involvement. The Society of Abdominal Radiology's Endometriosis Disease-Focused Panel presents this consensus document to establish an MRI lexicon for endometriosis MRI evaluation and anatomic localization.