FIG. 4.

Sensitivity of in-vivo λ|| compared to histology for assessing hyperacute ventrolateral white matter (VLWM) integrity. Hyperacute λ|| maps are displayed with representative histological sections obtained from animals sacrificed immediately after diffusion tensor imaging (DTI) scans. Each column of histological sections is from the same animal. Outlines on the λ|| maps encompass image voxels displaying normal threshold values (mean ± 2 standard deviations) within regions of spared normal VLWM. Histological regions of interest are represented by boxes in the VLWM of each corresponding MR image. Silver staining and SMI-31 (neurofilament immunostaining) both depict progressively increasing axonal swelling and vacuolation indicative of cytotoxic edema as injury severity increases. Aside from the obvious morphological changes, no changes are evident in sections immunostained with myelin basic protein (MBP) over the range of injury grades (scale bar = 100 μm). Color image is available online at www.liebertonline.com/neu.