Magnetic resonance imaging manifestations of decidualized endometriotic cysts: Comparative study with ovarian cancers associated with endometriotic cysts

Purpose: The purpose of the study was to investigate the magnetic resonance imaging findings of decidualized endometriotic cysts in comparison with endometriotic cysts associated with ovarian cancers.

Methods: Eighteen decidualized endometriotic cysts and 24 ovarian cancers were retrospectively assessed on height, signal intensity of the solid component on T2- and diffusion-weighted imaging, apparent diffusion coefficient value of the solid component, size of the lesion, and signal intensity of the intracystic fluid on T1-weighted imaging.

Results: The heights of the solid components in the decidualized endometriotic cystswere inferior to 11.1mm, significantly lower compared with the ovarian cancers. Similarly, decidualized tissues showed significantly higher signals on T2-weighted imaging and higher apparent diffusion coefficient values compared with ovarian cancers but not on diffusion-weighted imaging. The decidualized endometriotic cysts were also significantly smaller. Intracystic fluids showed higher signal in the decidualized endometriotic cysts compared with ovarian cancers on T1-weighted imaging.

Conclusions: In pregnant subjects, the presence of endometriotic cysts with low-height solid component showing high signal intensities on T2-weighted imaging is highly indicative of decidualization.