Characterization of parotid gland tumors: Whole-tumor histogram analysis of diffusion weighted imaging, diffusion kurtosis imaging, and intravoxel incoherent motion – A pilot study

•The whole-tumor histogram analysis of diffusion MRI could help to characterize parotid gland tumors.•The intravoxel incoherent motion model and combined diffusion model had better diagnostic specificity and accuracy than diffusion weighted imaging model in differentiating benign and malignant parotid gland tumors.•The diffusion kurtosis imaging model had similar diagnostic performance compared with diffusion weighted imaging model.•Diffusion parameters may serve as potential imaging biomarkers for the prediction of Ki-67 expression. To investigate the diagnostic performance of histogram features of diffusion parameters in characterizating parotid gland tumors. From December 2018 to January 2023, patients who underwent diffusion weighted imaging (DWI), diffusion kurtosis imaging (DKI), and intravoxel incoherent motion (IVIM) were consecutively enrolled in this retrospective study. The histogram features of diffusion parameters, including apparent diffusion coefficient (ADC), diffusion coefficient (Dk), diffusion kurtosis (K), pure diffusion coefficient (D), pseudo-diffusion coefficient (DP), and perfusion fraction (FP) were analyzed. The Mann-Whitney U test was used for comparison between benign parotid gland tumors (BPGTs) and malignant parotid gland tumors (MPGTs). Receiver operating characteristic curve and logistic regression analysis were used to identify the differential diagnostic performance. The Spearman’s correlation coefficient was used to analyze the correlation between diffusion parameters and Ki-67 labeling index. For diffusion MRI, twenty-three histogram features of diffusion parameters showed significant differences between BPGTs and MPGTs (all P