MRI is the modality of choice for evaluating lesions of the brachial plexus. The brachial plexus is a network of nerves that exits the lower cervical spine, traveling with the subclavian neurovascular structures, into the axilla and finally into the arm, and innervating the entire upper extremity. Patients with lesions in these regions may experience neuropathies, or what are referred to as “brachial plexopathies”.
The multiplanar imaging capability of MRI, and the exquisite soft tissue contrast make it an ideal modality to examine the brachial plexus. Mass lesions at the apices of the lungs can compress the plexus, fractures of the clavicle can impinge on and damage the plexus, and traumatic injuries can result in avulsion of the roots of the plexus from the cervical spine. MRI of the brachial plexus should be performed on a high field strength magnet.