Characterization of hemorrhagic adnexal lesions with MR imaging: blinded reader study.

To assess the performance of published criteria for differentiation of endometriomas from other hemorrhagic adnexal lesions with magnetic resonance (MR) imaging, 74 lesions with pathologic proof in 46 patients were evaluated by means of a 1.5-T system with use of conventional T1-weighted and either T2-weighted spin-echo (SE) or fast SE sequences. The MR images were independently presented to each of three blinded readers, and receiver operating characteristic (ROC) curve analysis was performed. The criterion of a cyst with high signal intensity on short repetition time (TR)/echo time (TE) images and shading on long TR/TE images had a mean sensitivity of 68%, mean specificity of 83%, and mean accuracy of 76% for diagnosis of endometrioma. Ancillary findings previously reported to be suggestive of endometrioma (eg, low-signal-intensity rims, adhesions, bowel tethering, and implants) were proved inaccurate and showed low interobserver agreement. ROC analysis showed similar area measurements among the three radiologists for diagnosis of endometrioma. MR imaging had only moderate accuracy in distinction of endometriomas from other hemorrhagic adnexal lesions.