Diagnostic possibility of diffusion tensor imaging for the evaluation of myometrial invasion in endometrial cancer: An ex vivo study

Abstract

To investigate the feasibility of magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) for evaluating the myometrial invasion of uterine endometrial cancer. Twelve specimens of uterine endometrial cancer were obtained. The depth of myometrial invasion was classified as stage E (limited to the endometrium; n = 4), stage S (superficial invasion of less than 50% of the myometrium; n = 5), or stage D (deep invasion of greater than 50% of the myometrium; n = 3). The specimens were fixed in 10% formalin and stored at 4°C before imaging. At 15 hours after fixation, MRI was performed using a 4.7-T experimental imager/spectrometer system. We found a high fractional anisotropy (FA) value zone (anisotropic zone) at the myometrium adjacent to the tumor on FA maps of histopathological stage S and stage D cancers, whereas the anisotropic zone did not exist in stage E cancers. Histopathological analysis showed that compared to the other regions, the anisotropic zone had tightly packed stromal tissue. The disruption of the anisotropic zone was consistent with myometrial invasion. Our ex vivo study suggests that DTI might be a useful tool for the diagnosis of myometrial invasion of uterine endometrial cancer ex vivo.