The Role of Dynamic Contrast-Enhanced Magnetic Resonance Imaging Parameters in Head-Neck Tumors

We evaluated dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in various head-neck masses, some of which are very rare tumors whose DCE-MRI have not been published to date. The purpose of this study was to investigate DCE-MRI in the differentiation of benign versus malignant lesions and to evaluate the DCE-MRI parameters most predictive for malignancy. Forty-one head-neck tumors including parotid gland tumors in 41 patients were examined at gadolinium-enhanced dynamic MR imaging. There were 26 malignant and 15 benign tumors. DCE-MR images were obtained between four and six minutes. Time-signal intensity curves (TICs) of the tumors on dynamic MR images were plotted, and then time of peak enhancement (Tpeak), and enhancement ratios (ER) with different times (such as ER30, ER60, ER90, ER120, ERmax) were also calculated. Data of the benign and malignant group with head-neck masses were compared by Mann-Whitney U-test. The mean values of time to peak (Tpeak) were found to be significantly shorter for the malignant group than the benign tumors (P<0.05). The mean enhancement rates of malignant lesions were ER30: 60.62±52.62, ER60: 105.65±56.26, ER90: 113.17±45.83, ER120: 116.59±46.75 and ERmax: 128.56±56.51 whereas the mean enhancement rate of benign lesions were ER30: 67.35±60.78, ER60: 79.79±63.33, ER90: 84.53±64.92, ER120: 88.41±67.07 and ERmax: 112.06±66.48. The mean signal intensity values of the 60th second (ER60) and 90th second (ER90) were significantly different from other values for predicting malignancy (P<.05). The parameters obtained from the time-signal intensity curve are important in differentiating benign and malignant enhancing lesions in dynamic head-neck MR imaging. DCE-MRI cannot replace standard MR imaging sequences for evaluating head-neck masses, but in addition to routine MR imaging it will improve differentiation between benign and malignant lesions.