Visualizing axon regeneration after peripheral nerve injury with magnetic resonance tractography

Diffusion tensor imaging (DTI) with tractography is an MRI technique that can visualize nerve pathways by taking advantage of anisotropy of water diffusion in tracts with longitudinally oriented fibers. To date, no study in humans has shown that DTI and tractography can follow regeneration of axons during recovery from traumatic peripheral neve injury. We show that tractography is able to identify regenerating axons advancing through a graft repair of an injured neve, and demonstrate correlation with evidence of recovery on serial clinical, electrodiagnostic, and muscle MRI assessments.