Ladak H M, Milner J S, Steinman D A
Imaging Research Labs, John P. Robarts Research Institute, London, ON, Canada.
J Biomech Eng. 2000 Feb;122(1):96-9. doi: 10.1115/1.429646.
The current trend in computational hemodynamics is to employ realistic models derived from ex vivo or in vivo imaging. Such studies typically produce a series of images from which the lumen boundaries must first be individually extracted (i.e., two-dimensional segmentation), and then serially reconstructed to produce the three-dimensional lumen surface geometry. In this paper, we present a rapid three-dimensional segmentation technique that combines these two steps, based on the idea of an expanding virtual balloon. This three-dimensional technique is demonstrated in application to finite element meshing and CFD modeling of flow in the carotid bifurcation of a normal volunteer imaged with black blood MRI. Wall shear stress patterns computed using a mesh generated with the three-dimensional technique agree well with those computed using a mesh generated from conventional two-dimensional segmentation and serial reconstruction. In addition to reducing the time required to extract the lumen surface from hours to minutes, our approach is easy to learn and use and requires minimal user intervention, which can potentially increase the accuracy and precision of quantitative and longitudinal studies of hemodynamics and vascular disease.
计算血液动力学的当前趋势是采用从离体或体内成像得出的逼真模型。此类研究通常会生成一系列图像，必须首先从这些图像中逐个提取管腔边界（即二维分割），然后进行串行重建以生成三维管腔表面几何形状。在本文中，我们基于扩展虚拟球囊的理念，提出了一种将这两个步骤结合起来的快速三维分割技术。这种三维技术在应用于有限元网格划分以及对一名正常志愿者的颈动脉分叉处血流进行CFD建模（该志愿者通过黑血MRI成像）时得到了验证。使用三维技术生成的网格计算出的壁面剪应力模式与使用传统二维分割和串行重建生成的网格计算出的结果吻合良好。除了将提取管腔表面所需的时间从数小时缩短至数分钟外，我们的方法易于学习和使用，并且需要最少的用户干预，这有可能提高血液动力学和血管疾病定量及纵向研究的准确性和精确性。
