Top row shows images from allograft with mild CCAR (A-D), the bottom row shows images of an allograft with severe CCAR (E-H). A few spots of hypointensity can be seen in T2* weighted in vivo CCMRI (A) resulting from labeled macrophage infiltration in different regions of the allograft experiecnin mild rejection. There are a larger number of dark spots detected in the severly rejecting allograft (E). These dark spots were confirmed by MRM at 11.7 T (B and F). The corresponding tissue sections stating with anti-rat EDI antibody (C and G) were used to confirm macrophage infiltration. The H&£ staining indicated a mild rejecting allograft graft (D) has less CCAR dchanges. The more concentrated macrophage accumulated in the encdocardium, adventitita, and severe intimal thickening in the severly rejecting allograft.