Evaluation of known endometriosis with MRI requires a slightly different protocol to a routine pelvic MRI (see Pelvic MRI protocol: routine), and should probably be reserved for known cases of endometriosis rather than for the assessment of pelvic pain.
IV (or IM) Buscopan is administered to reduce bowel peristalsis and hence improve image quality.
A good protocol involves:
- body coil
- T1W and T2W axial
- T1W fat-suppressed sequences 1: axial, sagittal and coronal
Gadolinium is not particularly useful in the evaluation of endometriomas 2 and does not improve detection of very small implants as small vessels enhance and may be misinterpreted as a small endometriotic deposit 1. Additionally, enhancement of endometrial deposits is variable post contrast and does not differentiate from other benign or malignant processes.
- 1. Sugimura K, Okizuka H, Imaoka I et-al. Pelvic endometriosis: detection and diagnosis with chemical shift MR imaging. Radiology. 1993;188 (2): 435-8. Radiology (abstract) - Pubmed citation
- 2. Ascher SM, Agrawal R, Bis KG et-al. Endometriosis: appearance and detection with conventional and contrast-enhanced fat-suppressed spin-echo techniques. J Magn Reson Imaging. 5 (3): 251-7. - Pubmed citation
- 3. Ha HK, Lim YT, Kim HS et-al. Diagnosis of pelvic endometriosis: fat-suppressed T1-weighted vs conventional MR images. AJR Am J Roentgenol. 1994;163 (1): 127-31. AJR Am J Roentgenol (abstract) - Pubmed citation