Aortic specimens were fixed in 10% paraformaldehyde. From five different lesions on the lower thoracic aorta, we cut paraffin-embedded 4 µm thick sections on the axial plane. These were stained with Prussian blue to identify the accumulation of iron oxide. We also stained macrophages immunohistochemically with RAM11, and compared Prussian blue-and RAM11-stained areas. For quantitative assessment, we measured the Prussian blue-stained area in one FOV (magnification, 200×) in three different lesions for each histological section of the lower intrathoracic aorta (using Image-Pro Plus; Media Cybernetics, Silver Spring, MD), and calculated the average values. In addition, the amount of iron per unit weight (300 µg) of the lower submit your manuscript | www.dovepress.com Dovepress Dovepress intrathoracic aortic specimens of dose 3 rabbits was measured by nuclear magnetic resonance (Minispec MQ20; Bruker Optics, Billerica, MA) (20 MHz, 0.47 T).