Mechanical and Structural Characteristics of Carotid Plaques by Combined Analysis With Echotracking System and MR Imaging
Mechanical and Structural Characteristics of Carotid Plaques by Combined Analysis With Echotracking System and MR Imaging
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DOI：
10.1016/j.jcmg.2011.01.017
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发表时间：
2011-05-01
影响因子：
14
通讯作者：
Laurent, Stephane
中科院分区：
文献类型：
--
作者：
Beaussier, Helene;Naggara, Olivier;Laurent, Stephane
结论：本研究的目的是通过高分辨率磁共振成像（HR-MRI）将回声跟踪评估的颈动脉粥样硬化斑块的动脉力学与其组成相关联。分析斑块的机械参数和结构之间的关系可以更好地理解导致斑块材料机械疲劳、斑块破裂和缺血事件的机制。特定的纵向应变梯度（减少的应变，即，斑块水平处的径向应变低于相邻节段处的径向应变）已经在患有高血压、血脂异常或2型糖尿病的患者的颈总动脉（CCA）上的动脉粥样硬化斑块中显示。这种功能behavior.METHODS四十六个颈动脉斑块27例进行了评价，斑块存在于颈动脉分叉的网站，并扩展到CCA的结构异常。在27例患者中，9例既往有颈动脉狭窄同侧缺血性卒中（有症状），18例无症状。在4cm长的颈总动脉段上，用无创超声跟踪系统测量128个部位的力学参数，并计算应变梯度。通过HR-MRI非侵入性地确定斑块组成。HR-MRI上的RE S U L T S复合斑块（即，美国心脏协会[AHA] IV至VIII期）比简单斑块（即，AHA I至III期; p = 0.046）。HR-MRI证实复杂斑块与回声跟踪的外部重塑相关，并且具有比邻近CCA更低的扩张性（17.0 +/- 5.0 MPa（-1）vs. 21.7 +/- 7.3 MPa（-1）; p = 0.007）。在HR-MRI的脂质核心斑块中观察到外部重塑，更频繁的症状carotids.CONCLUSIONS这些研究结果表明，“复杂”斑块的纵向力学遵循一个特定的模式减少应变。他们还表明，与外部重塑相关的应变减少可能是高危斑块的一个特征。（J Am科尔Cardiol Img 2011;4：468-77）（C）美国心脏病学会基金会2011年
OBJECTIVES The purpose of this study was to correlate the arterial mechanics of carotid atherosclerotic plaques assessed from echotracking with their composition by high-resolution magnetic resonance imaging (HR-MRI).BACKGROUND Analysis of the relationship between mechanical parameters and structure of the plaque allows better understanding of the mechanisms leading to mechanical fatigue of plaque material, plaque rupture, and ischemic events. A specific longitudinal gradient of strain (reduced strain, i.e., lower radial strain at the plaque level than at the adjacent segment) has been shown in atherosclerotic plaques on the common carotid artery (CCA) in patients with hypertension, dyslipidemia, or type 2 diabetes mellitus. The structural abnormalities underlying this functional behavior have not been determined.METHODS Forty-six carotid plaques from 27 patients were evaluated; plaques were present at the site of the carotid bifurcation and extended to the CCA. Among the 27 patients, 9 had previous ischemic stroke ipsilateral to carotid stenosis (symptomatic) and 18 had not (asymptomatic). Mechanical parameters were measured at 128 sites on a 4-cm long CCA segment by noninvasive echotracking system, and strain gradient was calculated. Plaque composition was noninvasively determined by HR-MRI. R E S U L T S Complex plaques at HR-MRI (i.e., American Heart Association [AHA] stages IV to VIII) more often displayed a reduced strain than the simple plaques (i.e., AHA stages I to III; p = 0.046). HR-MRI verified complex plaques were associated with an outer remodeling upon echotracking, and had a lower distensibility than adjacent CCA (17.0 +/- 5.0 MPa(-1) vs. 21.7 +/- 7.3 MPa(-1); p = 0.007). An outer remodeling was observed in plaques with a lipid core at HR-MRI and was more frequent in symptomatic carotids.CONCLUSIONS These findings indicate that the longitudinal mechanics of "complex" plaques follows a specific pattern of reduced strain. They also suggest that reduced strain, associated with an outer remodeling, may be a feature of high-risk plaques. (J Am Coll Cardiol Img 2011;4:468-77) (C) 2011 by the American College of Cardiology Foundation