CT evaluation of myometrium invasion in endometrial carcinoma.

Myometrium invasion (M) is one of the principal prognostic factors in the early clinical stages of endometrial carcinoma and can be evaluated presurgically only by CT, although with conflicting results. We compared CT of 65 patients with early clinical stage endometrial carcinomas with the corresponding anatomopathological findings. Myometrial infiltration of the same degree may present different CT images. Therefore, we identified five fundamental CT patterns, each of which corresponded to one of the three degrees of myometrium infiltration (M1, M2, M3). Furthermore, we defined the infiltration index as the ratio of minimum free myometrium to maximum free myometrium. Overall diagnostic accuracy was 76%; however, for clinical purposes CT provided adequate guidelines for therapeutic decisions in 93% of the cases. These criteria proved to be less reliable in elderly women with atrophic myometria, especially when the neoplasia was polypoid in shape.