Correlation Between Diagnostic Value of Diffusion Kurtosis Imaging for Nasopharyngeal Carcinoma and Ki-67 Expression

Objective: The objective of this study was to observe the correlation between multiple quantitative parameters of magnetic resonance diffusion kurtosis imaging and expression of proliferation-related antigen Ki-67 in nasopharyngeal carcinoma. Methods: The imaging data of 25 cases receiving 1.5 T magnetic resonance imaging and pathologically diagnosed as nasopharyngeal carcinoma were retrospectively analyzed. They were divided into Ki-67 high-expression group (n = 13) and low-expression group (n = 12). Diffusion kurtosis imaging parameters in parenchymal lesions were measured by 2 observers. The consistency of measurement results of the 2 observers was detected using intraclass correlation coefficient. The efficiency of differential diagnosis was assessed using receiver operating characteristic curve. The correlation between each parameter and Ki-67 expression index was explored through the Pearson's analysis. Results: The consistency of parameters of lesions measured by 2 observers was good in the 2 groups (intraclass correlation coefficient > 0.75). In the Ki-67 high-expression group, mean kurtosis, axial kurtosis, and radial kurtosis were higher, while mean diffusivity, axial diffusivity, and radial diffusivity were lower than those in the Ki-67 low-expression group (P< .05). Area under the curve values of mean kurtosis, axial kurtosis, radial kurtosis, mean diffusivity, axial diffusivity, and radial diffusivity for predicting high Ki-67 expression were 0.984, 0.922, 0.899, 0.903, 0.974, and 0.878, respectively. Mean kurtosis, axial kurtosis, and radial kurtosis were positively correlated with Ki-67 expression index, while mean diffusivity, axial diffusivity, and radial diffusivity were negatively correlated with this index (P < .05). Conclusion: The values of mean kurtosis, axial kurtosis, radial kurtosis, mean diffusivity, axial diffusivity, and radial diffusivity in the diffusion kurtosis imaging sequence are correlated with Ki-67 expression in nasopharyngeal carcinoma, and they have the potential to reflect the proliferation degree of nasopharyngeal carcinoma cells. Mean kurtosis is the optimal parameter. Keywords: Nasopharyngeal carcinoma, Ki-67, magnetic resonance, diffusion kurtosis imaging