Alternative Imaging Techniques for Endometriosis:

Transvaginal ultrasound (TVUS) is the first imaging approach for patients presenting with symptoms suggestive of endometriosis. TVUS is a widely available dynamic test which allows localization of the endometriotic deposits within the pelvis. However, ultrasound is limited by its restricted field of view, particularly in extra-pelvic disease. Magnetic resonance imaging (MRI) is highly sensitive and specific in the detection of endometriotic deposits. MRI is particularly useful in visualizing areas that are difficult to access at laparoscopy, for example, retroperitoneal disease and deposits beneath dense adhesions causing obliteration of the pouch of Douglas. MRI provides an anatomical map prior to surgery, outlining the extent of disease including depth of bowel or bladder invasion, parametrial and ureteric involvement and identifying extra-pelvic disease. Large, complex endometriomas seen on TVUS can be fully characterized with MRI to confirm or exclude endometriosis associated malignancy. This chapter will discuss the role that MRI plays in accurate pre-operative planning, multi-disciplinary discussion and patient counselling. Recommended MRI protocols and typical imaging features of endometriosis in different locations will also be discussed.