الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Summary and Conclusion
• Determining whether a clinically diagnosed adnexal mass is benign or malignant is frequently not possible until surgical exploration and histologic examination are performed. Consequently, it may not be possible to decide preoperatively whether conservative or radical surgery is appropriate. A reliable method with which to differentiate a benign from a malignant adnexal mass would provide a basis for optimal preoperative planning.
• Magnetic resonance (MR) imaging provides useful information for characterization of various ovarian masses. MRI can reveal morphologic characteristics such as papillary projections, nodularity, septa, solid portions and signal intensity on T1- and T2-weighted images, but none of these criteria reliably distinguish between benign and malignant tumors. Diffusion-weighted imaging is sensitive to changes in the microdiffusion of water into both intracellular and extracellular spaces and its use may improve MR characterization of ovarian lesions.
• By performing DWI using different b-values, quantitative analysis, namely, the calculation of apparent diffusion coefficient (ADC) is possible and can be displayed as a parametric map (ADC map). Restricted water diffusion demonstrates high signal intensity on DWI and lower ADC values on ADC map.
Our study was conducted on 26 complex adnexal masses; and presented an individual analysis of the diagnostic performance of DWI as an optional cost effective alternative to post contrast studies during the routine MR examination.
DWI had shown 100% sensitivity in its individual performance with specificity 70 %. Such specificity value was attributed to the presence of 3 benign masses that have mimicked malignancy on DWI due their misleading signal intensities of restricted diffusion. These masses were: ovarian fibromas (n=2) and sclerosing stromal tumor (n=1).
According to us, the addition of DWI to the conventional MRI improved the specificity (90 %) and overall accuracy (96.2 %)
In conclusion:
• The solo performance of DWI is not an applicable way to discriminate benign from malignant ovarian masses.
• DWI can confirm or exclude potential malignancy in complex ovarian masses; provided:
i) Inclusion of the conventional MRI data.
ii) Combined analysis of DWI quantitative and qualitative criteria
iii) Awareness of the possible sequence pitfalls.