Department of Radiology and Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, South Korea.
JACC Cardiovasc Imaging. 2010 Nov;3(11):1127-35. doi: 10.1016/j.jcmg.2010.08.012.
We investigated the contributing factors for plaque enhancement and examined the relationships between regional contrast enhancement and the inflammatory activity of atherosclerotic plaques in an experimental rabbit model using contrast-enhanced high-resolution 3-dimensional (3D) black-blood magnetic resonance imaging (MRI) in comparison with histopathologic analysis.
Inflammation plays a critical role in plaque initiation, progression, and disruption. As such, inflammation represents an emerging target for the treatment of atherosclerosis. MRI findings suggest that contrast agent-induced signal enhancement is associated with the degree of macrophage infiltration and neovessels that can be detected in plaque.
Ten atherosclerotic rabbits and 3 normal control rabbits underwent high-resolution 3D contrast-enhanced black-blood MRI. Magnetic resonance images and the corresponding histopathologic sections were divided into 4 quadrants. Plaque composition was analyzed for each quadrant according to histopathologic criteria (percent of lipid-rich, fibrous, macrophage area and microvessel density) and imaging criteria (enhancement ratio [ER], ER = signal intensity(post)/signal intensity(pre)). Multiple linear regression analysis was performed to determine independent factors for plaque enhancement.
A total of 62 noncalcified plaques (n = 248; 156 lipid-rich quadrants and 92 fibrous quadrants) were identified based on histopathologic analysis. Mean ER values were significantly higher in atherosclerotic vessel walls than in normal vessel walls (2.03 ± 0.25 vs. 1.58 ± 0.15; p = 0.017). The mean ER values were significantly higher in lipid-rich quadrants compared with the fibrous quadrants (2.14 ± 0.31 vs. 1.84 ± 0.21; p = 0.001). Mean ER values were significantly higher in macrophage-rich plaques compared with the macrophage-poor plaques (2.21 ± 0.28 vs. 1.81 ± 0.22; p = 0.001). Using multiple regression analysis, macrophage area and microvessel density were associated independently with ER values that reflected plaque enhancement (p < 0.001).
Contrast-enhanced high-resolution 3D black-blood MRI may be an efficient method to detect plaque inflammation.
我们通过对比增强高分辨率 3 维（3D）黑血磁共振成像（MRI）与组织病理学分析，研究了斑块增强的影响因素，并在实验性兔动脉粥样硬化模型中探讨了局部对比增强与斑块炎症活性之间的关系。
炎症在斑块的发生、进展和破裂中起着关键作用。因此，炎症是动脉粥样硬化治疗的一个新兴靶点。MRI 研究结果表明，对比剂诱导的信号增强与巨噬细胞浸润程度和斑块内可检测到的新生血管有关。
10 只动脉粥样硬化兔和 3 只正常对照兔进行高分辨率 3D 对比增强黑血 MRI。将磁共振图像及其相应的组织病理学切片分为 4 个象限。根据组织病理学标准（富含脂质、纤维、巨噬细胞面积和微血管密度的百分比）和影像学标准（增强比 [ER]，ER = 信号强度（post）/信号强度（pre））对每个象限的斑块成分进行分析。采用多元线性回归分析确定斑块增强的独立影响因素。
根据组织病理学分析，共确定了 62 个非钙化斑块（n = 248；156 个富含脂质的象限和 92 个纤维象限）。动脉粥样硬化血管壁的平均 ER 值明显高于正常血管壁（2.03 ± 0.25 比 1.58 ± 0.15；p = 0.017）。富含脂质象限的平均 ER 值明显高于纤维象限（2.14 ± 0.31 比 1.84 ± 0.21；p = 0.001）。富含巨噬细胞的斑块的平均 ER 值明显高于巨噬细胞较少的斑块（2.21 ± 0.28 比 1.81 ± 0.22；p = 0.001）。多元回归分析显示，巨噬细胞面积和微血管密度与反映斑块增强的 ER 值独立相关（p < 0.001）。
对比增强高分辨率 3D 黑血 MRI 可能是一种有效的检测斑块炎症的方法。
