Imaging Protocols in Deep Infiltrating Endometriosis (DIE) Integrating ESGE/ESUR/Enzian Guidelines into Routine Radiology Practice

on
Imaging Protocols in Deep Infiltrating Endometriosis (DIE): Integrating ESGE/ESUR/Enzian Guidelines

Imaging Protocols in Deep Infiltrating Endometriosis (DIE)

Integrating ESGE/ESUR/Enzian Guidelines into Routine Radiology Practice

The Significance of DIE Imaging

Deep Infiltrating Endometriosis (DIE) is a chronic, progressive, and often underdiagnosed condition causing significant pain, infertility, and potential organ dysfunction. Accurate imaging is fundamental to its management.

Chronic & Underdiagnosed

DIE's impact on quality of life is profound. A structured imaging approach is key to overcoming the long diagnostic delays that allow the disease to progress.

MRI: The Mapping Modality

Magnetic Resonance Imaging (MRI) is widely accepted as the gold standard for providing a comprehensive pre-surgical map, detailing the full extent of the disease across all pelvic compartments.

Structured Protocol is Key

Adopting a standardized MRI protocol and reporting system ensures diagnostic consistency, provides surgically relevant information, and aligns local practice with crucial international guidelines.

Overview of International Guidelines

The approach to DIE is shaped by several key international guidelines that standardize diagnosis and management, with a strong emphasis on imaging.

ESGE/ESUR/ISUOG (2021)

A joint consensus providing detailed recommendations on MRI protocols and structured reporting. It advocates for standardized techniques to improve communication and patient management, positioning MRI as a key problem-solving tool.

#Enzian Classification (2020 Revision)

A comprehensive anatomical classification system specifically designed for DIE. It allows for a standardized description of lesion location and severity, applicable to both imaging and surgical findings, facilitating research and multidisciplinary communication.

ACOG/SRS/ASRM

Guidelines from major US societies emphasize the critical role of imaging for pre-operative planning in patients with endometriosis-related pain and infertility, helping to guide surgical strategy and patient counseling.

MRI Protocol: Technical Parameters

A standardized MRI protocol is crucial for optimal DIE assessment. The following parameters are based on ESUR recommendations.

  • Timing: Ideally performed in the 2nd half of the menstrual cycle or during hormonal suppressive therapy.
  • Preparation: Mild bladder filling is recommended. Rectal/vaginal opacification with gel is optional but can be helpful for delineating fornices and the rectal wall. An anti-peristaltic agent is advised to reduce motion artifact.
  • Coils: A pelvic phased-array coil is standard for achieving optimal signal-to-noise ratio.
  • High-resolution T2-weighted (T2W): The cornerstone for anatomical detail. Must be acquired in Axial, Sagittal, and Coronal planes.
  • T1-weighted (T1W) with and without Fat Saturation: Essential for identifying hemorrhage. Acquired in Axial and Sagittal planes. Fat saturation is critical for confirming blood products.
  • Optional Sequences:
    • Diffusion-Weighted Imaging (DWI): Useful adjunct if malignancy is suspected or to assess lesion cellularity.
    • Contrast-enhanced T1W FS: Not routine. Reserved for cases where infection, abscess, or malignant transformation is a concern.

Structured Reporting: Compartment-Based Approach

A systematic, compartment-based approach to reporting is essential for clarity and surgical relevance.

Anterior Compartment

  • Key Structures: Bladder, vesicouterine pouch, round ligaments.
  • Report on: Lesion size, depth of bladder wall invasion, distance from ureteric orifices, and obliteration of the vesicouterine space.

Middle Compartment

  • Key Structures: Uterus, ovaries, fallopian tubes.
  • Report on: Presence of adenomyosis, size and characteristics of endometriomas, ovarian mobility ("kissing ovaries" sign), and signs of hydrosalpinx.

Posterior Compartment

  • Key Structures: Uterosacral ligaments (USLs), rectovaginal septum (RVS), Pouch of Douglas, rectosigmoid colon.
  • Report on: USL nodularity/thickening, RVS infiltration, obliteration of the Pouch of Douglas, and for bowel lesions: location, length, depth of invasion, and percentage of circumference involved.

#Enzian Classification: Mapping DIE

The #Enzian classification provides a standardized method for describing the anatomical location and extent of DIE, applicable to imaging and surgery.

Select a compartment

Click a button above to see the detailed description and grading for that anatomical compartment.

Standardized inclusion of #Enzian classification in radiology reports is encouraged to improve communication and research.

MRI Checklist: Essential Reporting Elements

A comprehensive MRI report for DIE should systematically address these key findings to ensure nothing is missed.

  • Uterosacral ligaments: Assess for thickening and nodularity.
  • Posterior vaginal fornix: Look for infiltration and angle distortion.
  • Rectovaginal septum: Identify T2 dark (fibrotic) lesions.
  • Rectosigmoid colon: Detail the depth, length, and circumferential involvement.
  • Bladder wall: Note any thickening or nodules.
  • Ureters: Check for signs of entrapment or resulting hydronephrosis.
  • Ovaries: Report endometriomas and the "kissing sign" of adhesions.
  • Tubes: Evaluate for hydrosalpinx and other signs of adhesions.
  • Uterus: Note features of co-existing adenomyosis.

Tips for Accurate DIE Imaging Interpretation

Maximizing the diagnostic yield of MRI for DIE involves careful attention to technique and interpretation nuances.

  • T2 is your anatomical map; T1 Fat Sat confirms hemorrhage. Use high-resolution T2W images to define anatomy and fibrotic lesions. Use T1W with fat saturation to confidently identify hemorrhagic foci, which confirms active glandular components.
  • Always assess uterine mobility and organ interfaces. Look for indirect signs of adhesions like distorted anatomy, tethering of organs (e.g., fixed uterine retroversion), and the obliteration of fat planes between structures.
  • Look for obliteration of fat planes and distorted angles. The loss of normal fat planes separating pelvic organs is a key sign of infiltration. Abnormal angulation of the uterus or bowel loops also indicates underlying adhesions.
  • Use adjunctive techniques if available. Vaginal or rectal gel can improve delineation of the vaginal fornices and rectal wall. Cine MRI sequences can offer insights into pelvic organ mobility.

Standardized Reporting Format

A structured reporting template enhances clarity and ensures all critical information is conveyed.

1. Clinical History: State indication and key symptoms.

2. Technique: Detail the MRI protocol used.

3. Findings by Compartment: Systematically describe findings for each pelvic compartment (Anterior, Middle, Posterior). Use BOLD for measurements and specify LEFT/RIGHT.

4. Impression: Summarize the key positive findings and their significance. Include #Enzian staging if appropriate.

5. Patient-friendly Summary (Optional but Recommended): A brief summary in layperson's terms to aid patient communication.

Illustrative Case Examples

Visual examples are crucial for understanding the imaging appearances of DIE. Below are descriptions of typical findings that would be illustrated with annotated MRI images.

Case 1: Posterior Compartment DIE

Imaging Description: A sagittal T2W image would show a T2 hypointense, spiculated nodule in the retrocervical region obliterating the fat plane and infiltrating the anterior rectal wall. An axial T2W image would demonstrate the rectal wall thickening and asymmetric involvement of the uterosacral ligaments.

Example #Enzian: (m)A2, (m)B1(r), (m)C1

Case 2: Bladder Endometriosis

Imaging Description: A sagittal T2W image would reveal a T2 hypointense nodule involving the bladder dome, indenting the bladder lumen. The depth of detrusor muscle invasion would be assessed. An axial T1W FS image might show small hyperintense foci within the lesion.

Example #Enzian: (m)FB2

Case 3: "Kissing Ovaries" & POD Obliteration

Imaging Description: An axial T1W FS image would show bilateral hyperintense ovarian cysts (endometriomas). An axial T2W image would demonstrate the "T2 shading" effect within the cysts and show the ovaries adherent in the midline ("kissing ovaries"), with fibrotic tissue obliterating the Pouch of Douglas.

Example #Enzian: (m)O3(bilateral), (m)T3

Summary & Key Takeaways

Effective management of DIE hinges on accurate imaging guided by standardized protocols.

  • MRI is central to DIE management. A structured protocol provides the detailed anatomical map essential for non-invasive diagnosis and pre-surgical planning.
  • Adopt guideline-based reporting. Adherence to ESGE/ESUR guidelines and use of the #Enzian classification are key to ensuring consistency and clarity.
  • Consistency improves outcomes. Standardized practices enhance detection, facilitate better surgical planning, and improve communication within the multidisciplinary care team.

The ultimate goal is to leverage advanced imaging to improve the diagnostic journey, optimize therapeutic interventions, and enhance the quality of life for individuals affected by DIE.

Comments

Post a Comment