Preoperative assessment of myometrial invasion of endometrial cancer by MR imaging and intrauterine ultrasonography with a high-frequency probe: preliminary study.

This study was undertaken to assess the capabilities of intrauterine ultrasonography performed while inflating the endometrial cavity with fluid and magnetic resonance imaging as a means to assess the depth of myometrial invasion by endometrial cancer preoperatively. Twenty women with endometrial disorders underwent preoperative intrauterine ultrasonography and magnetic resonance imaging. We introduced the probe and hysteroscope simultaneously into the uterine cavity and observed both the uterine cavity surface and cross-sectional uterine muscle. We classified the depth of myometrial invasion as none, superficial (less than half of the myometrium), or deep (more than half of the myometrium). The accuracy of magnetic resonance imaging and intrauterine ultrasonography in assessing the depth of myometrial invasion was 85%. In two cases, intrauterine sonography was able to demonstrate superficial myometrial invasion that could not be diagnosed by magnetic resonance imaging. In contrast, intrauterine ultrasonography was unable to diagnose myometrial invasion in two cases in which magnetic resonance imaging could diagnose it. Intrauterine sonography may be useful for estimation of myometrial invasion of endometrial cancer.