Efficacy of diffusion-weighted magnetic resonance imaging in the diagnosis and staging of endometrial tumors.

PURPOSE The goal of this study was to evaluate the efficacy of diffusion-weighted imaging (DWI) in differentiating between benign and malignant endometrial lesions and determinining tumor grade. It also aimed to determine the contribution of the DWI to the diagnosis by detection of the myometrial invasion depth in malignant lesions. MATERIALS AND METHODS The lesions were classified as benign (n=14) or malignant (n=42) according to the histopathological results and, the mean apparent diffusion coefficent (ADC) values were compared. For determining the myometrial invasion depth of malignant lesions, T2W, DWI and dynamic contrast-enhanced T1-weighted images (DCET1WI) were evaluated individually. RESULTS The sensitivity, specificity and area under the curve for discriminating between malignant and benign lesions by using cutoff ADC value of 1.10×10(-3)s/mm(2) were 85.7%, 92.8% and 0.95, respectively. According to the histopathological grading, there was no difference for the mean ADC values. For both observers the diagnostic accuracy of MRI in determining the depth of myometrial invasion in malignant lesions was found to be 87.1%, 89.7% and 76.9%, 76.9% for T2WI-DWI and DCET1WI, respectively. CONCLUSION DWI and ADC measurements can accurately discriminate endometrial cavity lesions as benign or malignant. T2WI-DWI is highly effective in determining the depth of myometrial invasion.