Abstract: This study investigated the value of apparent diffusion coefficient (ADC) histogram of magnetic resonance imaging (MRI) in the diagnosis of endometrial cancer and the degree of tumor invasion. 98 patients with endometrial cancer were selected as the case group, and 100 patients with uterine submucosal fibroids were selected as the control group. Both the two groups of patients underwent MRI examination, and then drew and compared the ADC histogram of the interesting region in MRI. 98 patients with endometrial cancer were stratified according to the degree of tumor infiltrating. The average value of ADC, ADC 10th, ADC 25th, ADC 50th, ADC 75th and ADC 95th in the case group were significantly lower than those in the control group (P<0.05). The AUC of ADC 10th in the differential diagnosis of endometrial cancer and uterine submucosal fibroids was 0.762, and the AUC of ADC 25th in the differential diagnosis of endometrial cancer and uterine submucosal fibroids was 0.842. Among 98 patients with endometrial cancer, 58 patients had myometrial infiltration depth<1/2 myometrium, and 40 patients had myometrial infiltration depth ≥ 1/2 myometrium. The mean value of ADC, measured value of ADC 10th, ADC 25th and ADC 50th in patients with myometrial infiltration depth<1/2 were significantly higher than those in patients with depth ≥ 1/2 (P<0.05). The sensitivity of ADC 10th in differential diagnosis of endometrial carcer with different depth of myometrial invasion was 90.17%, the specificity was 72.80%, and the AUC value was 0.856. MRI ADC histogram parameters are of great value in the differential diagnosis of endometrial cancer and uterine submucosal fibroids. It has a great significance to analyze the depth of invasion of endometrial cancer by MRI ADC histogram before operation.

Key words: magnetic resonance imaging, apparent diffusion coefficient, histogram, endometrial cancer, infiltration