Ersoy I, Bunyak F, Palaniappan K, Sun M, Forgacs G
Department of Computer Science, University of Missouri-Columbia, Columbia MO 65211, USA.
Med Image Comput Comput Assist Interv. 2008;11(Pt 1):376-83. doi: 10.1007/978-3-540-85988-8_45.
Cell adhesion and spreading within the extracellular matrix (ECM) plays an important role in cell motility, cell growth and tissue organization. Measuring cell spreading dynamics enables the investigation of cell mechanosensitivity to external mechanical stimuli, such as substrate rigidity. A common approach to measure cell spreading dynamics is to take time lapse images and quantify cell size and perimeter as a function of time. In our experiments, differences in cell characteristics between different treatments are subtle and require accurate measurements of cell parameters across a large population of cells to ensure an adequate sample size for statistical hypothesis testing. This paper presents a new approach to estimate accurate cell boundaries with complex shapes by applying a modified geodesic active contour level set method that directly utilizes the halo effect typically seen in phase contrast microscopy. Contour evolution is guided by edge profiles in a perpendicular direction to ensure convergence to the correct cell boundary. The proposed approach is tested on bovine aortic endothelial cell images under different treatments, and demonstrates accurate segmentation for a wide range of cell sizes and shapes compared to manual ground truth.
细胞在细胞外基质（ECM）中的黏附和铺展在细胞运动、细胞生长和组织形成中起着重要作用。测量细胞铺展动力学能够研究细胞对外部机械刺激（如底物硬度）的机械敏感性。测量细胞铺展动力学的一种常用方法是拍摄延时图像，并将细胞大小和周长作为时间的函数进行量化。在我们的实验中，不同处理之间细胞特征的差异很细微，需要对大量细胞的细胞参数进行准确测量，以确保有足够的样本量进行统计假设检验。本文提出了一种新方法，通过应用改进的测地线活动轮廓水平集方法来估计具有复杂形状的准确细胞边界，该方法直接利用了相差显微镜中常见的光晕效应。轮廓演化由垂直方向的边缘轮廓引导，以确保收敛到正确的细胞边界。所提出的方法在不同处理下的牛主动脉内皮细胞图像上进行了测试，与手动标注的真实情况相比，该方法对各种细胞大小和形状都能进行准确分割。
