Diffusion-weighted imaging with different 'b' values in differentiating benign from malignant lesions in the female pelvis

The aim of this study is to investigate the clinical usage of diffusion-weighted MRI with different b values pre-diagnosed pelvic mass in female patients.The study comprised 167 malignant and benign lesions in 154 cases with an age range of 15 to 82 having pelvic tumor pre-diagnosis and requested lower abdomen MR imaging in MR unit of the department of radiology between october 2009 and november 2010. Diffusion weighted EPI imaging of these patients have been performed at respectively b250, b500, b750, b1000 gradient values. ADC values of lesions have been measured on the pelvic tumor cases.Mean ADC values (b250, b500, b750, b1000) of 47 patients with malign lesions were measured (respectively 1.19x10?3, 1.12x10?3, 1.05x10?3, 0.94x10?3 s/mm2) below than the mean ADC values of 120 patients with benign lesions (respectively 2.17x10?3, 2.04x10?3, 1.97x10?3, 1.94x10?3 s/mm2) and the difference was considered to be statistically significant (p<0,05).We designed our study with different b values and we found statistically significant differences in whole values between malign and benign masses. However, we found that image resolution was declined and was difficult to detect the lesions under the b 500 values. We tought using the values between b 500 and b 1000 would be more appropriate in assesing the pelvic region.We conclude that DWI, being used routinely in addition to convantionel imaging modalities, will provide essentional benefits in differentiating malignant and benign pelvic masses.Key Words: Magnetic Resonance Imaging (MRI), Diffusion-Weighted Imaging (DWI), ADC, pelvic mass.