Figure 5.

Histological analysis of abdominal aortic aneurysms (AAA) and correlation with $T_2^{*}$ signal loss on MRI. A: Immunohistochemical AAA staining showed mural macrophage infiltration and endothelial cell expression within the AAA wall. Perl's iron staining showed greater accumulation of RGD‐HFn‐Fe₃O₄ in the media and adventitia of AAA wall (AAA RGD⁺) compared to HFn‐Fe₃O₄ (AAA RGD^–), colocalizing with both macrophages (asterisks) and endothelial cells (dagger). The control aortic wall showed minimal Perl's iron staining in both RGD⁺ and RGD^– groups. B: There was a close correlation between the total number of Perl's iron‐stained cells and % SI loss in the AAA (n = 10, r = 0.83, P = 0.003).