Oral carcinoma: Clinical evaluation using diffusion kurtosis imaging and its correlation with histopathologic findings

PURPOSE: In this study, we aimed to determine the usefulness of diffusion kurtosis imaging (DKI) as a noninvasive method for evaluation of the histologic grade and lymph node metastasis in patients with oral carcinoma. MATERIALS AND METHODS: Twenty-seven patients with oral carcinoma were examined with a 3-T MR system and 16-channel coil. DKI data were obtained by a single-shot echo-planar imaging sequence with repetition time, 10,000ms; echo time, 94ms; field of view, 250x204.25ms; matrix, 120x98; section thickness, 4mm; four b values of 0, 500, 1000, and 2000s/mm(2); and motion-probing gradients in three orthogonal directions. Diffusivity (D) and kurtosis (K) were calculated using the equation: S=S0 exp(-b D+b(2) D(2) K/6). Conventional apparent diffusion coefficient (ADC) was also calculated. The MR images were compared with the histopathologic findings. RESULTS: Relative to the histologic grades (Grades 1, 2, and 3) of the 27 oral carcinomas, D values showed a significant inverse correlation (r=-0.885; P<0.001) and K values showed a significant positive correlation (r=0.869; P<0.001), whereas ADC values showed no significant correlation (r=-0.311; P=0.115). When comparing between metastatic and non-metastatic lymph nodes, significant differences in the D values (P<0.001) and K values (P<0.001), but not the ADC values (P=0.110) became apparent. CONCLUSIONS: In patients with oral carcinoma, DKI seems to be clinically useful for the evaluation of histologic grades and lymph node metastasis