Rogowska J, Patel N A, Fujimoto J G, Brezinski M E
Orthopedics Department, Brigham and Women's Hospital/Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115, USA.
Heart. 2004 May;90(5):556-62. doi: 10.1136/hrt.2003.016956.
To evaluate optical coherence tomographic elastography as a method for assessing the elastic properties of atherosclerotic plaque and the parameters that influence interpretation.
Phantoms and aorta were examined in vitro to quantify speckle modulation and measure the displacement and strain maps. A correlation method was used as a speckle tracking technique for measuring axial and lateral displacement vectors and calculation of strain maps. The influence of correlation kernel size on accuracy of the method was evaluated.
In terms of a percentage error between calculated and measured displacements, the best results for phantoms were obtained with a 41 x 41 kernel (1.88% error). For both phantom and aorta images, it was found that, with the increasing size of cross correlation kernel, the axial and lateral displacement maps are less noisy and the displacement vectors are more clearly defined. However, the large kernels tend to average out the differences in displacements of small particles in phantoms and decrease the ability of speckle tracking to make microstructural assessments. Therefore, it is important to select kernel size carefully, based on the image features.
Optical tomographic elastography can be used to assess the microstructural properties of atherosclerotic tissue at micrometre scale resolution, but preselected analysis criteria must be understood in a critical interpretation of the results.
评估光学相干断层弹性成像作为一种评估动脉粥样硬化斑块弹性特性及影响解读参数的方法。
对体模和主动脉进行体外检查，以量化散斑调制并测量位移和应变图。使用相关方法作为散斑跟踪技术来测量轴向和横向位移矢量并计算应变图。评估相关内核大小对该方法准确性的影响。
就计算位移与测量位移之间的百分比误差而言，使用41×41内核时体模获得的结果最佳（误差为1.88%）。对于体模和主动脉图像均发现，随着互相关内核尺寸的增加，轴向和横向位移图的噪声更小，位移矢量更清晰。然而，大内核往往会使体模中小颗粒位移的差异平均化，并降低散斑跟踪进行微观结构评估的能力。因此，基于图像特征仔细选择内核大小很重要。
光学断层弹性成像可用于在微米级分辨率下评估动脉粥样硬化组织的微观结构特性，但在对结果进行批判性解读时必须理解预先选择的分析标准。
