MRI Pelvis MRI has been shown to have a sensitivity of 82% to 90% and specificity of 91% to 98% for the diagnosis of endometriomas and can be used when the findings on TVUS are indeterminate [34-36] or when assessment for deep infiltrating endometriosis is required prior to fertility-sparing surgery. Although IV contrast is useful for the assessment of PID and for determining if ovarian masses have enhancing components, IV contrast is not routinely used for the assessment of endometriosis [34]. The typical MRI features of an endometrioma are high signal on T1- weighted with low signal on T2-weighted images (T2 shading) from intracellular methemoglobin, crosslinking of proteins, and iron. Additionally, the T2 dark spot sign has 93% specificity in differentiating endometriomas from hemorrhagic cysts, whereas T2 shading is sensitive but not specific for endometriomas [37]. Deep infiltrating endometriosis presents as low signal intensity regions with or without hyperintense foci on T2- and/or T1-weighted images. Despite administration of gadolinium, studies do not attempt to demonstrate a difference in detection of deep infiltrating endometriosis with gadolinium as compared to without [38,39]. Adhesions are frequently present in endometriosis and can be suspected, in the presence of a uterus, fixed in retroversion, low-signal intensity bands, obliteration of organ interfaces, and/or obliteration of the cul-de-sac [40]. In a study of 159 women who underwent surgery for clinical suspicion of deep infiltrating endometriosis, MRI was 92.4% sensitive and 94.6% specific in detecting intestinal endometriosis, 88% sensitive and 83.3% specific in detecting deep infiltrating endometriosis in posterior locations (uterosacral ligament, retrocervical, rectovaginal septum, vaginal fornix), and 50% sensitive and 97.3% specific in detecting bladder wall endometriosis [38].
Female Infertility. MRI Pelvis MRI has been shown to have a sensitivity of 82% to 90% and specificity of 91% to 98% for the diagnosis of endometriomas and can be used when the findings on TVUS are indeterminate [34-36] or when assessment for deep infiltrating endometriosis is required prior to fertility-sparing surgery. Although IV contrast is useful for the assessment of PID and for determining if ovarian masses have enhancing components, IV contrast is not routinely used for the assessment of endometriosis [34]. The typical MRI features of an endometrioma are high signal on T1- weighted with low signal on T2-weighted images (T2 shading) from intracellular methemoglobin, crosslinking of proteins, and iron. Additionally, the T2 dark spot sign has 93% specificity in differentiating endometriomas from hemorrhagic cysts, whereas T2 shading is sensitive but not specific for endometriomas [37]. Deep infiltrating endometriosis presents as low signal intensity regions with or without hyperintense foci on T2- and/or T1-weighted images. Despite administration of gadolinium, studies do not attempt to demonstrate a difference in detection of deep infiltrating endometriosis with gadolinium as compared to without [38,39]. Adhesions are frequently present in endometriosis and can be suspected, in the presence of a uterus, fixed in retroversion, low-signal intensity bands, obliteration of organ interfaces, and/or obliteration of the cul-de-sac [40]. In a study of 159 women who underwent surgery for clinical suspicion of deep infiltrating endometriosis, MRI was 92.4% sensitive and 94.6% specific in detecting intestinal endometriosis, 88% sensitive and 83.3% specific in detecting deep infiltrating endometriosis in posterior locations (uterosacral ligament, retrocervical, rectovaginal septum, vaginal fornix), and 50% sensitive and 97.3% specific in detecting bladder wall endometriosis [38].