Diffusion-weighted echo planar imaging of ovarian tumors: Is it useful to measure apparent diffusion coefficients?

Purpose: Our goal was to test the hypothesis, as previously reported in other studies. that apparent diffusion coefficients (ADCs) provide specific information to diagnose ovarian tumors. especially to discriminate between benign and malignant lesions. Method: T1- and T2-weighted spin echo imaging and diffusion-weighted echo planar imaging were performed in 31 women with 61 cystic components of ovarian tumors. Results: The lesions that showed typical watery intensity, hypointensity in T1-weighted imaging, and hyperintensity in T2-weighted imaging had similar ADCs, ranging from 1.54 to 1.84 x 10(-3) mm(2) /s. The lesions that showed signal intensity different from typical watery intensity in conventional MRI tended to have low ADCs. In endometrial cysts. the mean ADC of the subgroup that showed typical watery intensity was higher than that of other subgroups. Conclusion: With conventional MRI. a tendency of ADCs could be predicted. ADCs may not provide additional information, especially to discriminate benign from malignant lesions.