Value of adding diffusion-weighted imaging to conventional MRI for differentiation complex solid from cystic ovarian masses

Background Conventional MRI has an established role in gynecologic imaging. However, increasing clinical demand for improved lesion characterization and disease mapping to optimize patient management has resulted in the incorporation of newer sequences, such as diffusion-weighted imaging (DWI), into routine protocols for pelvic MRI. DWI provides functional information on the microenvironment of water in tissues, hence augmenting the morphologic information derived from conventional MRIs. Aim Aim is to define the role of DWI and apparent diffusion coefficient (ADC) in characterizing complex ovarian masses, with particular concern to differentiating benign versus malignant masses. Patients and methods Eighty patients who had complex ovarian masses between February 2019 and December 2020 underwent pelvic MRI and DWI at b values of 0, 500, and 1000 s/mm2 at 1.5-T unit (Philips Ingenia). Analysis of the pathological specimen with lesion morphology, signal characteristics, and correlation with the appearance at DWI followed by ADC value (both solid and cystic parts) measurement was obtained. Results Included masses proved pathologically benign 41 (51.2%) and 39 (48.8%) malignant. ADC solid component of malignant lesions shows no statistically significant difference from that of the benign lesions, while ADC values of cystic component in malignant masses were significantly higher than those in benign masses (P≤0.001). The receiver operator characteristic analysis indicated that a cut-off ADC (cystic part) value of 2.3×10−3 mm/s may be the optimal one for differentiating between benign and malignant masses. Conclusion The combination of DWI with ADC-value measurements and conventional MRI is useful for differentiating benign and malignant masses.