Characterization of head and neck lesions with diffusion-weighted MR imaging and the apparent diffusion coefficient values

Abstract

PurposeThe aim of this study was to determine the role of diffusion-weighted MR imaging (DWI) and the apparent diffusion coefficient (ADC) in characterization of head and neck lesions. Patients and methodsMR imaging including diffusion-weighted sequences was performed on 43 patients presented with head and neck lesions. Images were obtained with a diffusion-weighted factor (b factor) of 100, 500, and 1000s/mm2. ADC maps were reconstructed, and the ADC value of the lesions was calculated. ResultsThe mean ADC value of malignant tumors was (1.02±0.22)×10−3mm2/s (n=31). The mean ADC value of benign tumors was (1.62±0.27)×10−3mm2/s (n=12). The mean ADC of lymphomas was significantly lower than that of carcinomas. The difference in the ADC value between the malignant tumors and benign lesions was statistically significant (p<0.001). Selection of (1.2)×10−3mm2/s as a threshold value of ADC for differentiating benign from malignant tumors yielded the best result, with an accuracy of 94%, sensitivity of 95%, specificity of 92%, positive predictive value of 92% and negative predictive value of 94%. ConclusionDWI and the ADC measurement are promising, non-invasive imaging approach that can be used for characterization of head and neck lesions. It can help differentiate malignant tumors from benign lesions.