针对建立三维血管矢量表面模型时血管树存在复杂分叉和管径狭小的问题,提出一种高效可靠的矢量建模方法.首先将血管树骨架线从血管体素中提取出来并重组为各条单分支,在此基础上,结合中间点的最优截面管径重建出各个单分支管道表面;然后利用类Delaunay三角剖分对每个分叉区域进行表面过渡拼接,将各个分支表面融合成一个符合CGAL标准的闭合多面体;最后通过对模型表面进行曲面细分,得到一个逼真细腻的三维模型.该方法在重建分叉区域时充分利用了分支之间的“互吃”关系,计算开销小.实验结果表明,文中方法效率高,重建模型准确,优于已有的建模方法.
Targeting at the possibly existing complex furcations and narrow tubes which are problematic in reconstructing vectorial surface of blood vessels,we introduce an efficient and reliable vector-based modeling method.First,the skeletal representation of vascular volume is extracted from its segmented volume and further converted into an adaptive one constituted by a number of single lines,whose optimal radii are computed simultaneously upon continuous center points.And then based on this adaptive skeleton and the optimal radii,we reconstruct tubular surface for each single line.And for each furcating part,we use our Delaunay triangulation-like method to merge the surfaces of its branching single lines into a closed one which meets the CGAL standard.Finally,the whole surface is further subdivided to provide an exquisite and accurate model.The Delaunay triangulation-like method takes full advantage of the eating-each-other relationships among these single lines with small computation overhead required.The experimental outcomes show that our method is effective and the resulted model is accurate,surpassing the pre-existing vector-based methods.