Role of Magnetic Resonance Diffusion Weighted Imaging (DWI) in Differentiation between Benign and Malignant Ovarian Masses, MOSTAFA H.M. OTHMAN, ALAA EL-DEEN M. ISMAIL, HOSAM EL-DEEN G. MOHAMED and RADWA A. ABO EL-KASEM
Abstract
Background: Determining whether a clinically diagnosed adnexal mass is benign or malignant is frequently not possible until surgical exploration and histologic examination are performed. Magnetic Resonance (MR) imaging provides useful information for characterization of various ovarian masses. Diffusion-weighted imaging is sensitive to changes in the micro diffusion of water into both intracellular and extracellular spaces and its use may improve MR characteri-zation of ovarian lesions.
Aim of Study: To reveal added value of Diffusion Weighted Images (DWI) in differentiation between benign and malignant ovarian masses.
Patients and Methods: The study included 26 female patients referred from Gynecology to Radiology Department with indeterminate complex and solid ovarian masses based on preliminary abdominopelvic ultrasound; pelvic MRI and Diffusion Weighted Imaging (DWI) were conducted.
Results: Both conventional MRI and DWI had shown 100% sensitivity while the specificity was higher for DWI 70% compared to conventional MRI sequences 50%, as well as the accuracy which was 80.8% for conventional MRI while that of DWI was 88.5%. Addition of DWI to the conventional MRI increased the specificity and the accuracy of examination to 90 and 96.6% respectively.
The mean ADC values for malignant lesions was (0.9 X 10–3±0.1SDmm2/s), while that for benign lesions was (1.5 X 10–3±0.4SDmm2/s), The lower ADC values associated with the malignant group were found to be statistically significant (p-value <0.05) with 0.9 X 10–3mm2/s may be an optimal cutoff value for differentiating benign and malignant ovarian tumors with sensitivity 81.25%, specificity 100%.
Conclusion: Combined evaluation of conventional MRI sequences as well as DWI (both qualitative and quantitative analysis) can confirm or exclude potential malignancy in suspicious ovarian masses taking into consideration possible sequence pitfalls.