MRI appearance of nerve regeneration in a surgically repaired ulnar nerve

Background and Purpose: Magnetic resonance imaging (MRI) findings for surgical repair of a transected nerve have not been published. We describe the first reported postoperative MR imaging findings of a repaired transected ulnar nerve. Methods: A patient presented to our institution following surgical repair of a severed ulnar nerve at the level of the forearm. MRI was obtained to evaluate postsurgical outcome and potential complications. Results: Magnetic resonance imaging demonstrates the presence of nerve fascicles that are clearly depicted above and below the level of injury but appear indistinct at the level of transection. Conclusion: To our knowledge, the MRI appearance of a repaired transected nerve has not been previously described. We believe that the MRI findings may be used to assess the anatomic progress of nerve healing and, when combined with a series of progressively favorable results from a focused neurologic exam, provide convincing evidence of nerve regeneration.