Standard diffusion-weighted, diffusion kurtosis and intravoxel incoherent motion MR imaging of sinonasal malignancies: correlations with Ki-67 proliferation status

To explore the correlations of parameters derived from standard diffusion-weighted imaging (DWI), diffusion kurtosis imaging (DKI) and intravoxel incoherent motion (IVIM) with the Ki-67 proliferation status. Seventy-five patients with histologically proven sinonasal malignancies who underwent standard DWI, DKI and IVIM were retrospectively reviewed. The mean, minimum, maximum and whole standard DWI [apparent diffusion coefficient (ADC)], DKI [diffusion kurtosis (K) and diffusion coefficient (Dk)] and IVIM [pure diffusion coefficient (D), pseudo-diffusion coefficient (D*) and perfusion fraction (f)] parameters were measured and correlated with the Ki-67 labelling index (LI). The Ki-67 LI was categorised as high (> 50%) or low ( 50%). The K and f values were positively correlated with the Ki-67 LI (rho = 0.295 similar to 0.532), whereas the ADC, Dk and D values were negatively correlated with the Ki-67 LI (rho = -0.443 similar to-0.277). The ADC, Dk and D values were lower, whereas the K value was higher in sinonasal malignancies with a high Ki-67 LI than in those in a low Ki-67 LI (all p < 0.05). A higher maximum K value (K-max > 0.977) independently predicted a high Ki-67 status [odds ratio (OR) = 7.614; 95% confidence interval (CI) = 2.197-38.674; p = 0.017]. ADC, Dk, K, D and f are correlated with Ki-67 LI. K-max is the strongest independent factor for predicting Ki-67 status. DWI-derived parameters from different models are capable of providing different pathophysiological information. DWI, DKI and IVIM parameters are associated with Ki-67 proliferation status. K (max) derived from DKI is the strongest independent factor for the prediction of Ki-67 proliferation status.