Abstract： Objective To compare the efficacy of MRI and DSA in assessment of carotid artery stenosis and atherosclerotic plaque.Methods Forty-six patients with carotid plaque detected by ultrasound were enrolled in this study,and 89 carotid arteries were evaluated by MRI and DSA.MRI examination was acquired with 3.0 T MR scanner and 8 channel phase-array surface coil.The MRI sequences consisted of pre-and post-contrast T1WI,T2WI,PDWI,TOF.Anterior-posterior and lateral views of carotid artery were performed on DSA.The degree of carotid artery stenosis was evaluated by the NASCET standard.Fibrous cap rupture,intraplaque hemorrhage,and calcification were also evaluated on MRI and DSA.Statistical comparison was performed with the Kappa value and paired Chi-square test.Results The degree of carotid artery stenosis was 50％ (16％-78％) on MRI and 47％ (7％-73％) on DSA.Two imaging modalities were in good consistency in evaluation of the degree of stenosis ( Kappa =0.882,P ＜ 0.01 ).There was statistical difference in detecting fibrous cap rupture by MRI and DSA (34 vessels vs 10 vessels,respectively,x2 =20.346,P ＜ 0.01 ).Furthermore,thirty-seven vessels with intraplaque hemorrhage and 71 vessels with calcification in the plaque were found on MRI but none on DSA.Conclusion MRI is a reliable tool in assessment of the degree of the carotid stenosis and it is superior to DSA in detecting fibrous cap rupture,intraplaque hemorrhage,and calcification.