Mass preserving nonrigid registration of CT lung images using cubic B-spline
Mass preserving nonrigid registration of CT lung images using cubic B-spline
复制标题
DOI：
10.1118/1.3193526
复制
发表时间：
2009-09-01
期刊：
影响因子：
3.8
通讯作者：
Lin, Ching-Long
中科院分区：
文献类型：
--
作者：
Yin, Youbing;Hoffman, Eric A.;Lin, Ching-Long
作者提出了一种非刚性图像配准方法，当两个体积之间的图像失真较大时，在两个吸气水平下屏气期间采集的两个计算机断层扫描（CT）衍生的肺数据集对齐。我们的目标是推导出一个三维翘曲函数，可用于与计算流体动力学研究。在对比的平方强度差（SSD）的总和，一个新的相似性标准，平方组织体积差（SSTVD）的总和，考虑到重建Hounsfield单位（缩放衰减系数，HU）与通货膨胀的变化。该新标准旨在最小化匹配区域之间的肺内的局部组织体积差异，从而在假设组织密度相对恒定的情况下保留肺的组织质量。局部组织体积差异由两个因素造成：由于变形引起的区域体积变化和由于膨胀引起的区域中组织含量分数变化。区域体积的变化是根据从翘曲函数导出的雅可比值计算的，并且部分组织含量的变化是根据基于重建的HU的油定量CT测量来估计的。采用多层B样条的组合对图像进行变形，并施加一个充分条件，即使对于体积差异较大的配准对也能确保一对一映射。在多分辨率框架下，采用有限记忆拟牛顿最小化方法对变换模型的参数进行优化。为了评价新相似性度量的有效性，作者对6个肺容积对进行了配准。使用半自动系统生成了100多个位于血管分叉处的注释标志。结果表明，SSTVD方法在所有六个配准对上产生的平均地标误差小于SSD方法。(C)2009年美国医学物理学家协会。[DOI：10.1118/1.3193526]
The authors propose a nonrigid image registration approach to align two computed-tomography (CT)-derived lung datasets acquired during breath-holds at two inspiratory levels when the image distortion between the two volumes is large. The goal is to derive a three-dimensional warping function that can be used in association with computational fluid dynamics studies. In contrast to the sum of squared intensity difference (SSD), a new similarity criterion, the sum of squared tissue volume difference (SSTVD), is introduced to take into account changes in reconstructed Hounsfield units (scaled attenuation coefficient, HU) with inflation. This new criterion aims to minimize the local tissue volume difference within the lungs between matched regions, thus preserving the tissue mass of the lungs if the tissue density is assumed to be relatively constant. The local tissue volume difference is contributed by two factors: Change in the regional volume due to the deformation and change in the fractional tissue content in a region due to inflation. The change in the regional volume is calculated from the Jacobian value derived from the warping function and the change in the fractional tissue content is estimated from reconstructed HU based oil quantitative CT measures. A composite of multilevel B-spline is adopted to deform images and a sufficient condition is imposed to ensure a one-to-one mapping even for a registration pair with large volume difference. Parameters of the transformation model are optimized by a limited-memory quasi-Newton minimization approach in a multiresolution framework. To evaluate the effectiveness of the new similarity measure, the authors performed registrations for six lung Volume pairs. Over 100 annotated landmarks located at vessel bifurcations were generated using a semiautomatic system. The results show that the SSTVD method yields smaller average landmark errors than the SSD method across all six registration pairs. (C) 2009 American Association of Physicists in Medicine. [DOI: 10.1118/1.3193526]