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 (T_peak), and enhancement ratios (ER) with different times (such as ER₃₀, ER₆₀, ER₉₀, ER₁₂₀, ER_max) 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 (T_peak) 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 ER_max: 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 ER_max: 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.