Update and review on the basics of brachial plexus imaging

Brachial plexopathy is a type of peripheral neuropathy. Injuries to the brachial plexus can be classified according to their severity, ranging from neuropraxia, the mildest form, to axonotmesis and neurotmesis, the most severe forms. The causes of brachial plexopathy include traumatic and non-traumatic injuries. Because the brachial plexus can sustain various types of injuries, different imaging modalities are required. Recent advances in diagnostic imaging have enabled better investigation of brachial plexopathy. This article reviews the major and most widely used imaging methods used for investigating brachial plexopathy along with newer modalities. The indications, advantages, and disadvantages of each modality are examined. The major factor in realizing the full potential of any imaging method is the knowledge of the requesting physician about the capabilities and limitations of each method. Magnetic resonance imaging (MRI) is the standard imaging modality for evaluating non-traumatic injury to the brachial plexus; however, there are several limitations to its use and, therefore, other modalities should be pursued. MR myelography should be used for traumatic meningoceles and root avulsions. MR neurography is a relatively new technique with massive potential. It is a tissue-specific modality with the ability to elicit morphological as well as pathological features of nerves. CT myelography is the gold standard for evaluating traumatic injury of the brachial plexus. Other potential uses are with tumors of the brachial plexus as well as obstetric brachial plexus palsies. Finally, sonography is addressed. With its ability to detect almost all plexopathies and the fact that it does not employ radiation and can be done in virtually every patient, it should be the baseline or, at least, the screening method for plexopathies.