Differentiation between benign and malignant ovarian masses using multiparametric MRI

To investigate the capabilities of multiparametric MRI including dynamic contrast enhanced (DCE) perfusion and diffusion-weighted imaging (DWI) to discriminate between benign and malignant ovarian masses.

A total of 43 women with a total of 43 ovarian masses were retrospectively included. They had a mean age of 51.26±18.05 (SD) years (range: 20-88years). Twenty women had benign and 23 had malignant ovarian tumors. All women had multiparametric MRI examinations including DWI (b50-b800) and DCE perfusion imaging at 1-5T. Results of DWI (apparent diffusion coefficient [ADC], b-800) and DCE imaging (volume transfer coefficient [K^trans], rate constant [K_ep], interstitial volume [V_e], initial area under the curve [iAUC]) were compared between benign and malignant ovarian masses.

Mean ADC was significantly lowed in malignant tumors (0.92±0.25 [SD]×10^-3 mm²/s (range: 0.6-1.6×10^-3 mm²/s) than in benign tumors (1.37±0.69 [SD]×10^-3 mm²/s; range: 0.4-2.9×10^-3 mm²/s) (P=0.011). B-800 was significantly greater in malignant tumors (80.61±24.73 [SD] s/mm²; range: 24-110 s/mm²) than in benign ones (61.15±22.17 [SD] s/mm²; range: 38-155 s/mm²) (P=0.010). K^trans was lower in benign tumors (0.13±0.06 [SD] min^-1; range: 0-0.2min^-1) than in malignant ones (0.25±0.16 [SD] min^-1; range: 0.1-0.8min^-1) (P=0.002). K_ep was significantly greater in malignant tumors (0.55±0.19 [SD] min^-1; range: 0.1-1.9min^-1) than in benign ones (0.44±0.38 [SD] min^-1; range: 0.2-1.1min^-1) (P=0.003). iAUC was greater in malignant tumors (15.59±7.98 [SD] mM/min; range: 6.6-42.1mM/min) than in benign ones (7.98±5.06 [SD] mM/min; range: 0.2-17.7mM/min) (P=0.001). No differences in V_e were found between benign and malignant masses (P=0.084). The area under the ROC curve was significant for all parameters but V_e. Logistic regression analysis revealed 5.590 and 11.637 times higher malignancy risk for an ADC≤0.93×10^-3 mm²/s and an iAUC≥13.88mM/min, respectively.

Multiparametric MRI has high accuracy in discrimination between benign and malignant ovarian masses. Therefore, adding these methods to the more common MRI protocol can help select the best treatment option in women with ovarian mass.