Differentiation of the various lesions causing an abnormality of the endometrial cavity using MR imaging: emphasis on enhancement patterns on dynamic studies and late contrast-enhanced T1-weighted images.

The objectives of this study were to determine the usefulness of magnetic resonance (MR) imaging in the differentiation of various lesions causing an abnormality of the endometrial cavity by evaluating the imaging features on dynamic contrast-enhanced study and late contrast-enhanced T1-weighted images (T1WI). Contrast-enhanced MR imaging of 59 pathologically proven lesions that showed an abnormality of the endometrial cavity, including 32 endometrial cancers, five sarcomas, nine hyperplastic polyps, nine submucosal myomas, three hyperplasia, and one adenomyoma, were retrospectively reviewed. The enhancement degree and patterns on dynamic contrast-enhanced study and late contrast-enhanced T1WI were compared among different pathologies. On dynamic contrast-enhanced study, 72% (23/32) of endometrial cancers showed early peak enhancement to be reached within 1 min following intravenous administration of contrast material. On late-contrast-enhanced T1WI, lesions showed weak enhancement with gradual washout. Ninety-five percent (21/22) of benign lesions and 100% (5/5) of sarcomas showed late peak enhancement to be reached in 2-3 min following intravenous administration of contrast material. On late contrast-enhanced T1WI, both of these lesions showed persistent strong enhancement. Different enhancement patterns on dynamic contrast-enhanced MR imaging and late contrast-enhanced T1WI can provide a useful clue in the differentiation of various lesions causing an abnormality of the endometrial cavity.