Review of Lumbosacral MR Neurography

Magnetic resonance neurography (MRN) is increasingly used for the evaluation of lumbosacral plexopathy and peripheral neuropathy.1 Although clinical evaluation and electroclinical studies are helpful in evaluating function, they are limited in their ability to characterize the underlying pathology. Electromyography is very sensitive for nerve injury but lacks specificity and cannot depict the level of anatomic detail often needed to localize the nerve lesion and for treatment planning. Furthermore, conventional imaging studies, such as MRI or CT, have a role in evaluating extrinsic structural abnormalities that may compress the nerves, such as retroperitoneal hematomas or pelvic abscesses, but are unable to adequately depict the lumbosacral plexus and peripheral nerves due to limited imaging contrast between neural tissue and adjacent soft tissues. With advances in MR technology and acquisition technique, MRN has become a frequently requested advanced imaging modality for the detection of lumbosacral plexopathy and muscles and nonneural structures in the lumbar spine and pelvis.The objective of this article is to illustrate the utility of lumbosacral MR neurography and provide clinical examples through which readers can increase their familiarity with interpretation of MRN findings in lumbosacral plexopathy and neuropathy.