From the Guidelines
Transvaginal Ultrasound (TVUS) and MRI Pelvis are the most accurate imaging modalities for assessing endometriosis.
Key Imaging Modalities
- TVUS: is known to be an accurate study for the evaluation of ovarian endometriomas 1 and has excellent performance for detection of deep endometriosis (DE) when using expanded protocols 1.
- MRI Pelvis: is an excellent imaging modality for the preoperative diagnosis of endometriosis 1 and has been shown to correspond well with surgical staging systems and histopathologic findings 1.
Important Considerations
- Expanded TVUS protocols: include evaluation of additional anatomic landmarks and scanning maneuvers, which have shown similar diagnostic performance to pelvic MRI 1.
- MRI protocols: tailored for detection of DE, with moderate bladder distention and vaginal contrast, can help improve lesion conspicuity involving these structures 1.
- IV contrast: is helpful in establishing the diagnosis of other pelvic conditions that may present with similar symptoms, such as uterine fibroids or other infectious or inflammatory disorders 1.
Limitations of Other Modalities
- Transabdominal US: has a limited field of view and may not be able to detect superficial or deep endometriosis lesions 1.
- FDG-PET/CT: has not been extensively studied for the detection of endometriosis, but may have potential as a diagnostic tool 1.
From the Research
Imaging Modalities for Endometriosis
The following imaging modalities are used to assess endometriosis:
- Transvaginal ultrasound (TVS)
- Magnetic resonance imaging (MRI)
- Three-dimensional sonography (3DUS)
Accuracy of Imaging Modalities
The accuracy of these imaging modalities is as follows:
- TVS is non-inferior to MRI in the diagnosis and assessment of deep infiltrating endometriosis (DIE) 2
- TVS can accurately diagnose ovarian endometriomas (OMAs) and deep infiltrating endometriosis (DIE) 2, 3
- MRI can accurately diagnose deep infiltrating endometriosis and has a wider field of vision 4, 5, 6
- 3DUS can accurately diagnose deep infiltrating endometriosis in specific locations 3
Recommendations
Based on the evidence, TVS should be considered as the first-line imaging modality in the diagnosis and assessment of endometriosis due to its satisfactory overall diagnostic accuracy, wide availability, and low cost 2 MRI can be used as a complementary imaging modality to TVS, especially in cases where a wider field of vision is needed 5, 6