Figure 1

Structural MRI, ∆R1, and concentration maps for the three NPs and Gd-DTPA. Structural images show injury, dark area near top of brain, ∆R1 and concentration maps show change in R1 and NP concentration between final and initial scans. Highest ∆R1 and concentration values correspond to the injured regions in the structural images. Concentration units for Gd-DTPA have been displayed as mM and for NPs as mg/mL in an attempt to maintain use of units most familiar for these particles.