MRI had sensitivity, specificity, accuracy rate in diagnosis of C5 root avulsion / rupture were: 83.3%, 75%, and 82.5%, C6 root avulsion / rupture were: 91.9%, 66.7% and 90%, C7 root avulsion / rupture were: 96.2%, 57.1%, 82.5%, C8 root avulsion / rupture were: 71.4%, 73.1% and 72.5%; T1 root avulsion / rupture were: 60.0%, 91.4% and 87.5%, upper trunk lesion: 88.9%, 83.9% and 85%, middle trunk: 87.5%, 90.9% and 90.0%, lower trunk: 94.4%, 92.5% and 60.0%, compared with surgery.