The Value of the Apparent Diffusion Coefficient in Differentiating Stage IA Endometrial Carcinoma From Normal Endometrium and Benign Diseases of the Endometrium

Abstract

To retrospectively assess the feasibility of diffusion-weighted (DW) magnetic resonance (MR) imaging of stage IA endometrial carcinoma and to investigate whether the apparent diffusion coefficient (ADC) values of stage IA endometrial carcinoma differ from those of normal endometrium and benign diseases of the endometrium. Study population included 28 women with surgically proven stage IA endometrial carcinoma, 30 women with stage IA cervical cancer with pathologically confirmed normal endometrium, and 19 women with proven benign diseases of the endometrium with dilation and curettage. All patients underwent conventional nonenhanced MR and axial oblique DW imaging procedures with b values of 0 and 1000 s/mm2 by using a 3-T MR scanner. Qualitative analysis of the signal intensity on DW imaging was performed for each patient. The ADC values of stage IA endometrial carcinoma were compared with those of normal endometrium and benign diseases of the endometrium, and the Wilcoxon rank sum test was used with a P < 0.05 considered statistically significant. All endometrial carcinomas and normal endometria exhibited a high signal intensity on DW images, whereas endometrial hyperplasia and polyp showed a low or intermediate signal intensity compared with normal outer myometrium. The mean (SD) ADC of stage IA endometrial carcinoma was 0.878 (0.185) x 10(-3) mm2/s, which was significantly lower (P < 0.01) than that of normal endometrium (1.446 [0.246] x 10(-3) mm2/s) and that of benign endometrial lesions (1.637 [0.178] x 10(-3) mm2/s) without any overlap. The measurements of the ADC values have the potential to quantitatively differentiate stage IA endometrial carcinoma from normal endometrium and benign diseases of the endometrium. We propose adding DW imaging as an adjunct sequence in the routine MR protocol for the assessment of uterine lesions.