Role of DWI MRI as a Recent Modality in Differentiation between Benign from Malignant Ovarian Tumors

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. Consequently, it may not be possible to decide pre-operatively whether conservative or radical surgery is appropriate. Areliable method with which to differentiate a benign from a malignant adnexal mass would provide a basis for optimal pre-operative planning. Aim of Study: To get judgment for the utilized MRI tools of assessment and to find out whether diffusion weighted imaging is a necessity or luxury in case we need to asses an adnexal mass. Patients and Methods: The current study is a prospective analysis that was conducted at Ain Shams University Hospital and Damnhour Scan Center from 2018 to 2019. The study was performed on 22 cases of ovarian tumors. 5 patients presented by abdominal enlargement, 5 were complaining of long standing abdominal pain, 7 came with other different complaints; 4 came complaining with frequency of micturition, dysuria, loss of weight and one case accidentally discovered during US examination. Results: DWI had shown 100% sensitivity in its individual performance; yet a low specificity which was 78.6%. Such low specificity value was attributed to the presence of benign masses that have mimicked malignancy on DWI; starting from their misleading signal intensities of restricted diffusion, down to their measured ADC values. These masses were: Mature teratomas and tubo-ovarian abscess. Conclusion: The solo performance of DWI is not an applicable way to discriminate benign from malignant adnexal masses due to its low specificity. According to us, DWI has sensitivity of (100%), but didn't improve the specificity (78.6%) or the accuracy (86.4%). DWI can help and increase confidence of MRI in assessment or exclude potential malig-nancy in complex adnexal masses; provided I) inclusion of the conventional MRI data, II) Combined analysis of DWI quantitative and qualitative criteria and iii) awareness of the possible sequence pitfalls.