Increased neovascularization in advanced lipid-rich atherosclerotic lesions detected by gadofluorine-M-enhanced MRI: implications for plaque vulnerability.

Background— Inflammation and neovascularization may play a significant role in atherosclerotic plaque progression and rupture. We evaluated gadofluorine-M-enhanced MRI for detection of plaque inflammation and neovascularization in an animal model of atherosclerosis. Methods and Results— Sixteen rabbits with aortic plaque and 6 normal control rabbits underwent gadofluorine-M-enhanced MRI. Eight rabbits had advanced atherosclerotic lesions, whereas the remaining 8 had early lesions. Magnetic resonance atherosclerotic plaque enhancement was meticulously compared with plaque inflammation and neovessel density as assessed by histopathology. Advanced plaques and early atheroma were enhanced after gadofluorine-M injection. Control animals displayed no enhancement. After accounting for the within-animal correlation of observations, mean contrast-to-noise ratio was significantly higher in advanced plaques than compared with early atheroma (4.29�0.21 versus 3.00�0.32; P=0.004). Macrophage density was higher in adva...