A computer-based method for determination of the cell-free layer width in microcirculation
A computer-based method for determination of the cell-free layer width in microcirculation
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DOI：
10.1080/10739680600556878
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发表时间：
2006-04-01
期刊：
影响因子：
2.4
通讯作者：
Johnson, PC
中科院分区：
文献类型：
--
作者：
Kim, S;Kong, RL;Johnson, PC
目的：红细胞柱与血管壁之间的无细胞层是微循环血管流体动力学阻力的重要决定因素。作者报道了一种连续测量微循环血管层宽度的方法。方法：根据微循环血管的视频图像，连续测定垂直于血管轴线的线性像素阵列的光强度。基于Otsu方法的阈值水平被用来建立无细胞层和红细胞柱之间的界面。为了验证该方法，在右旋糖酐500诱导红细胞聚集前后，从正常动脉压和降压状态下的大鼠脊髓斜方肌小静脉和小动脉获得750-4500帧/S的视频图像。结果：经Bland-Altman分析，在95%的置信限内，经相关系数(R-2)在90%~95%的范围内，手工测量结果与新方法的测量结果一致。更频繁的测量显示，随着动脉压和红细胞聚集性的变化，无细胞层宽度和平均值发生了显著、快速的变化。结论：一种新的基于计算机的技术已经开发出来，可以测量微循环中无细胞层宽度的快速、随时间变化的变化。
Objectives: The cell-free layer between the erythrocyte column and the vessel wall is an important determinant of hydrodynamic resistance in microcirculatory vessels. The authors report a method for continuous measurement of the width of this layer.Methods: The light intensity of a linear array of pixels perpendicular to the vessel axis is continuously determined from a video image of a microcirculatory vessel. A threshold level based on Otsu's method is used to establish the interface between the cell-free layer and the erythrocyte column. To test the method, video images at 750-4500 frames/s were obtained from venules and arterioles in rat spinotrapezius muscle at normal and reduced arterial pressures before and after induction of erythrocyte aggregation with Dextran 500. The current measurements were compared to manual measurements of the same images.Results: Values obtained by the manual and the new methods were in agreement within the 95% confidence limit by the Bland-Altman analysis and within 90-95% range by the correlation coefficient (R-2). The more frequent measurements reveal substantial, rapid variations in cell-free layer width and changes in mean values with alteration of arterial pressure and red cell aggregability.Conclusions: A new, computer-based technique has been developed that provides measurements of rapid, time-dependent variations in the width of the cell-free layer in the microcirculation.