Objectives: An optimized, longitudinal in vivo magnetic resonance vessel wall-imaging protocol was evaluated regarding its capability of detecting differences in the time-dependent atherosclerotic lesion progression in the aortic arch between ApoE(-/-) and double-deficient ApoE(-/-)/TNF(-/-) mice at comparatively early plaque development stages.
Materials and methods: Seven ApoE(-/-) and seven ApoE(-/-)/TNF(-/-) female mice underwent MRI at 11.75 teslas at four stages up to 26 weeks of age. A double-gated spin-echo MRI sequence was used with careful perpendicular slice positioning to visualize the vessel wall of the ascending aortic arch.
Results: Wall-thickness progression measured with MRI was significant at 11 weeks of age in ApoE(-/-) mice, but only at 26 weeks in ApoE(-/-)/TNF(-/-) mice. A significant correlation was found between MRI wall-thickness and lesion area determined on histology.
Conclusion: MRI was shown to be sensitive enough to reveal subtle genetically-induced differences in lesion progression at ages earlier than 25 weeks.