Razek AAKA, et al. - Using diffusion weighted imaging (DWI), researchers sought to differentiate sublingual thyroglossal duct cyst (TGDC) from midline dermoid cyst (DC). DWI of the floor of the mouth was undertaken in 22 consecutive patients (11 male and 11 female aged 5-15 years) with midline cystic lesion at the floor of the mouth. Outcomes support the reliability and reproducibility of DWI for differentiating sublingual TGDC from DC. When using apparent diffusion coefficient of 1.76 and 1.62 X10^-3 mm²/s as a threshold value for differentiating TGDC from DC, they obtained the best results with area under the curve of 0.94 and 0.96, accuracy of 90% and 86%, sensitivity of 91% and 91%%, specificity of 90% and 80%, negative predictive value of 90% and 88% and positive predictive value of 92% and 84% of both reviewers respectively.