Abstract: Objective To evaluate the diagnostic value of diffusion weighted imaging （DWI） for assessing radiation damage to parotid glands of miniature pigs. Methods Miniature pigs were exposed to single-dose radiation on either the left or right parotid gland（n=8） or they were not exposed to radiation（n=4），then all pigs were examined by conventional magnetic resonance imaging and DWI.Pathological changes and ADC values for parotid glands were recorded before and after irradiation. Results Before irradiation，the three groups did not differ significantly in salivary flow rate or ADC value（P>0.05）.The flow rate increased slightly in the control group over the course of the study，and both flow rate and ADC value were significantly lower in the irradiated groups than in the control group （P<0.05）.In addition， the two groups irradiated on the left or right parotid differed significantly in flow rate and ADC value（P<0.05）. Conclusions The ADC value may indicate microstructural changes in parotid gland tissue after irradiation，and DWI may prove a useful method for monitoring parotid gland radiosensitivity.

Key words: Diffusion weighted imaging, Parotid gland, Radiation damage