Spinal cord atrophy in injured rodents: high-resolution MRI.

Longitudinal magnetic resonance imaging (MRI) was performed in normal and spinal cord (SC)-injured rodents. A fast technique based on polar B-spline snake was developed to extract the SC contour from the MR images in order to estimate the cord atrophy. Based on pooled data from all of the imaging studies, the extracted contours correlated well with manually defined contours. Results from the injured group showed cord atrophy shortly after the contusion injury. The maximum amount of atrophy (9.7% +/- 3.5% decrease in the cross-sectional area (CSA)) occurred mainly at the epicenter around 14 days postinjury. The caudal and rostral segments in the injured group did not exhibit significant atrophy compared to the normal controls. The MRI-based atrophy measurements obtained in injured cords are consistent with previous histological findings.