Use-fullness of dynamic contrast-enhanced MR imaging and diffusion weighted MR imaging for differentiation of benign and malignant parotid tumors

Abstract

Objectives: To evaluate the usefullness of dynamic contrast-enhanced MR Imaging (DCE-MRI) and diffusion weighted imaging (DWI) for differentiating benign from malignant parotid tumors. Methods: Prospectively,DCE-MRI and DWI were performed in 112 patients, with 148 confirmed parotid masses. The differential optimal thresholds were determined. Results: WConsidering tumors with time-intensity curve (TIC) Type C as malignant, sensitivity, specificity, accuracy were 95%, 76%, 79%, respectively. Considering ADC threshold values 0.709×10-3mm2 /s<ADC<0.948×10-3mm2 /s as malignant, sensitivity, specificity, accuracy were 75%, 78%, 78%, respectively. Considering TIC Type C and ADC values 0.709×10-3mm2 /s<ADC<0.948×10-3mm2 /s as malignant, sensitivity, specificity, accuracy were 75%, 91%, 89%, respectively. With threshold Kep<1.118 min-1 and Ve >0.315 between Warthin and malignant tumors, threshold Kep>0.555 min-1 and Ve <0.605 between pleomorphic adenomas and malignant tumors, sensitivity, specificity, accuracy for malignancy were 70% vs 90%, 96% vs 74%, 92% vs 80%, respectively. Conclusion: DCE-MRI and DWI provide more information in differentiating benign from malignant parotid tumors.