Evaluation of cystic ovarian lesions using apparent diffusion coefficient calculated from turboFLASH MR images.

Serial turboFLASH (fast low-angle shot) images with and without diffusion-perfusion (DP) gradients were used to evaluate the contents of cystic ovarian lesions. 19 ovarian cysts seven serous cystadenomas, six mucinous cystadenomas and 13 malignant cystic ovarian tumours were studied. T1 and T2 weighted spin echo images, serial turboFLASH images with and without DP gradients (b = 295.1 and 0 s mm-2, respectively) were obtained. Using these images, the apparent diffusion coefficients (ADCs) were calculated within the cystic contents of these lesions. Approximately corrected ADC (ADC') values were also calculated in order to reduce T1 contamination from ADCs, using results of a phantom study. Ovarian cysts and serous cystadenomas showed larger ADC and ADC' values than the cystic contents of malignant ovarian lesions (p < 0.01). Mucinous cystadenomas show no distinct ADC difference to any other group of cases. However, if the highest ADC' loculus was selected as being representative, mucinous cystadenomas showed a larger ADC' value than malignant cystic neoplasms (p < 0.03). In conclusion, diffusion-weighted MRI is possibly of use in evaluating cystic contents of ovarian lesions.