摘要
利用磁共振标记技术对左心室壁进行局部三维有限元应变的分析。在一个心动周期内,分别拍摄24张短轴平面图像和长轴平面图像,然后进行合成,求解出健康人左心室壁上各个位置不同时刻的位移和应变,为临床应用和定量准确地评价心功能提供重要的理论依据。
This paper proposes a three-dimensional anal-
ysis method in local regions of the left ventricle by using
tagged MR imaging. The imaging slices are taken in long
axis and short axis of LV wall. At least two parallel slices
are prepared in each axis. The material points of inter-
est are traced between different phases of beating heart.
Two points are chosen on each intersection line of image
slices which surround the trace point. Three-dimensional
displacements of a point on an intersection line are de-
rived from the two-dimensional displacements on the two
perpendicular slices. By use of the interpolation function
of a hexahedral element in FEM, the displacement and
deformation gradients are derived from the displacements
of eight nodes. Displacements of points at systole with
respect to diastole can be calculated as a sum of each dis-
placement between each phase of beating. Green's strain
is also obtained by using a product of deformation gra-
dient between each phase. The proposed method has an
advantage of reducing the time of calculation by not trac-
ing all nodal points of the finite elements in the LV wall.
出处
《力学与实践》
CSCD
北大核心
2004年第3期65-67,共3页
Mechanics in Engineering
