Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Int J Cardiovasc Imaging. 2012 Jun;28(5):1181-91. doi: 10.1007/s10554-011-9910-6. Epub 2011 Jun 19.
We have applied an imaging system of phase-contrast X-ray CT to the detection of atherosclerotic plaque components by means of the differences of tissue mass densities. In this study, we investigated the effect of the anti-platelet therapies, widely used for secondly prevention of cardiovascular events, on plaque stability and examined whether this novel technique could detect the changes of plaque components under the therapy. Apolipoprotein E-deficient mice were fed on high-cholesterol diet alone and either with 0.1% cilostazol or clopidogrel for 10 weeks. We assessed atherosclerotic lesion volumes and components at brachiocephalic artery by the phase-contrast X-ray CT imaging and histochemistry. The phase-contrast X-ray CT imaging could reveal that cilostazol and clopidogrel significantly decreased atherosclerotic lesion volumes at brachiocephalic artery (31.2% reduction in cilostazol group and 37.4% reduction in clopidogrel group), compared with control group. In addition, the mass densities calculated by this method revealed the anti-platelet treatment increased stable plaque areas including high collagen content, but decreased unstable plaque areas including lipid and macrophage content. These findings were confirmed by histological analyses. Real-time PCR analyses indicated that anti-platelets inhibited gene expressions of cytokines and adhesion molecules, such as IFNγ and ICAM-1. Anti-platelet therapies had a beneficial effect on plaque stability maybe due to anti-inflammatory actions. Phase-contrast X-ray CT imaging could quantify the plaque volume and qualify the plaque components affected by anti-platelet therapies. This novel phase-contrast X-ray CT imaging system could be a plausible method to detect the unstable plaque non-invasively in the future.
我们应用了一种基于相衬 X 射线 CT 的成像系统，通过组织质量密度的差异来检测动脉粥样硬化斑块成分。在这项研究中，我们研究了抗血小板治疗（广泛用于心血管事件的二级预防）对斑块稳定性的影响，并探讨了这种新的技术是否能够检测到治疗过程中斑块成分的变化。载脂蛋白 E 缺陷小鼠单独喂食高胆固醇饮食，或同时给予西洛他唑或氯吡格雷治疗 10 周。我们通过相衬 X 射线 CT 成像和组织化学评估了肱动脉的动脉粥样硬化病变体积和成分。相衬 X 射线 CT 成像能够显示西洛他唑和氯吡格雷可显著降低肱动脉的动脉粥样硬化病变体积（西洛他唑组减少 31.2%，氯吡格雷组减少 37.4%），与对照组相比。此外，该方法计算的质量密度显示，抗血小板治疗增加了包括高胶原含量在内的稳定斑块区域，但减少了包括脂质和巨噬细胞含量在内的不稳定斑块区域。这些发现得到了组织学分析的证实。实时 PCR 分析表明，抗血小板药物抑制了细胞因子和粘附分子（如 IFNγ和 ICAM-1）的基因表达。抗血小板治疗对斑块稳定性有有益的影响，可能是由于抗炎作用。相衬 X 射线 CT 成像可以定量斑块体积，并定性受抗血小板治疗影响的斑块成分。这种新型的相衬 X 射线 CT 成像系统有望成为未来非侵入性检测不稳定斑块的一种方法。
