T raumatic brachial plexus injuries affect 1% of patients involved in major trauma (1). Brachial plexus injuries may cause permanent disability (2-6), pain (6-8), psychologic morbidity (9,10), and reduced quality of life (2,4,11). Early reconstructive nerve surgery is associated with better functional recovery in the upper limb (2,3,11,12), which improves quality of life (4). Nerve reconstruction for patients with root avulsion(s) is a clinical priority for several reasons. After root avulsion, the cell bodies of motor neurons in the spinal cord recede (4,5,12,13), so the limb never reanimates spontaneously. Because reimplantation of avulsed roots yields no meaningful recovery (14-16), nerve transfers are performed, which significantly improves function (11,17-20). Nerve transfers are relatively minor and cost-effective procedures (21,22) with low morbidity (20,23-25). Furthermore, 95% of patients with traumatic brachial plexus injuries have neuropathic pain (6), and the evolving evidence suggests that early reconstructive nerve surgery reduces cortical reorganization and thus neuropathic or phantom limb pain (26-28). Therefore, correctly identifying patients with root avulsions is of paramount importance. MRI is the best noninvasive test for brachial plexus injuries (29). MRI is superior to nerve and muscle electrophysiology studies (30), US (31-34), and intraoperative somatosensory-evoked potentials (35). Currently, MRI