Sonography Should Be the First Imaging Examination Done to Evaluate Patients With Suspected Endometriosis

Abstract

ndometriosis is defined as the presence of normal endometrial tissue occurring outside the endometrial cavity. This ectopic endometrial tissue responds to normal cyclic hormonal changes, resulting in localized bleeding, inflammation, and subsequent adhesion formation. As a result, endometriosis is a well-known cause of chronic pelvic pain in premenopausal women. The most common site and most recognized sonographic appearance of endometriosis is the ovarian cyst known as an endometrioma or chocolate cyst. Sonographically, an endometrioma is an ovarian cyst that has homogeneous low-level echoes with some areas of increased echogenicity (clot) but with no evidence of blood flow inside. 1 Many years ago, the sonographic diagnosis of endometriosis was reserved for patients with obvious endometriomas, thus missing the cause of pelvic pain in a large number of patients. We now know that endometriosis is also commonly found in other dependent areas of the pelvis, including the anterior and posterior cul-de-sac, the uterosacral ligaments, the bladder and bowel wall (rectosigmoid particularly), and the rectovaginal septum.