Diagnostic Approach for Brachial Plexus Injuries

Initial Evaluation and Imaging

The American College of Radiology recommends MRI of the brachial plexus as the gold standard first-line imaging test for evaluating brachial plexus injuries due to its superior soft-tissue contrast and spatial resolution 1, 2
Electrodiagnostic studies (EMG/NCS) should be performed to assess the severity and location of nerve injury, with correlation between abnormal intraneural signal on MRI and active radiculopathy on EMG 3
Imaging should ideally be delayed until approximately 1 month after trauma to allow for resolution of hemorrhage and edema, and for pseudomeningocele formation 4, 5, 2

MRI brachial plexus with dedicated protocol is the preferred initial imaging modality, including orthogonal views through the oblique planes of the plexus, T1-weighted, T2-weighted, fat-saturated T2-weighted sequences, STIR sequences 4, 1, 2
Determine if the injury is preganglionic (involving intraspinal nerve roots) or postganglionic (involving plexus lateral to dorsal root ganglion) as prognosis and reconstruction approaches differ 3, 5
Assess whether the nerve is completely ruptured (requiring early operative management) or stretched but intact 4, 3

Penetrating and open injuries typically require early surgical exploration 4, 1
Blunt and closed injuries may be managed operatively or non-operatively depending on severity 4, 1
Complete nerve ruptures generally have worse prognosis and often require early operative intervention 4, 1

Standard MRI protocols for the neck, chest, or spine are inadequate for proper evaluation of the brachial plexus; specialized brachial plexus protocols are required 1, 2
CT of the cervical spine alone cannot fully visualize the preganglionic nerve roots and has limited soft-tissue contrast resolution compared to MRI 4, 5