The ratio of EMG and MRI in diagnosis of tearing of nerve roots of brachial plexus before surgery is 55. 56% and 68. 52% respectively, and the combination of the two can increase the ratio to 85. 19%.

• 术前肌电圈和MRI检查对臂丛神经根撕脱诊断的符合率分别为55.；56%25和68