Abstract:Objective: To explore the correlations between biexponential model(IVIM) of diffusion-weighted imaging parameters and nasopharyngeal carcinoma(NPC) clinical stage, and to evaluate its value in assessing invasion and metastasis of NPC. Methods: Forty-nine newly diagnosed NPC patients received MRI examination and clinical staging was decided based on Chinese 2008 staging system. The correlations between IVIM parameters(ADCstand, ADCslow, ADCfast, Ffast) and clinical stage were analyzed. Results: T stage showed negative correlation with ADCslow(r=-0.356, P=0.012) and positive correlation with ADCfast(r=0.388, P=0.006). ADCstand showed a positive correlation with overall stage(r=0.410, P=0.003), N stage(r=0.313, P=0.029) and M stage(r=0.349, P=0.014). ADCstand showed significant differences in different overall stages, N stages and M stages(P<0.05), and ADCslow showed significant differences in the different overall stages, T stages and N stages(P<0.05). Conclusion: IVIM parameters of primary NPC lesions have significant correlations with clinical stages. IVIM parameters may act as imaging biomarkers for non-invasive assessing of the tumour microstructure, disease level and aggressiveness of NPC.