A pseudoinverse deformation vector field generator and its applications.
A pseudoinverse deformation vector field generator and its applications.
复制标题
一种伪逆变形矢量场发生器及其应用。
DOI:
10.1118/1.3301594
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发表时间:
2010
期刊:
影响因子:
3.8
通讯作者:
Siebers,JV
中科院分区:
文献类型:
--
作者:
Yan,C;Zhong,H;Murphy,M;Weiss,E;Siebers,JV
PurposeTo present, implement, and test aself‐consistent pseudoinverse displacement vector field(PIDVF) generator, which preserves the location of information mapped back‐and‐forth between image sets.MethodsThe algorithm is an iterative scheme based on nearest neighbor interpolation and a subsequent iterative search. Performance of the algorithm is benchmarked using a lung 4DCT data set with six CT images from different breathing phases and eight CT images for a single prostrate patient acquired on different days. A diffeomorphic deformable image registration is used to validate our PIDVFs. Additionally, the PIDVF is used to measure the self‐consistency of two nondiffeomorphic algorithms which do not use a self‐consistency constraint: The ITK Demons algorithm for the lung patient images and an in‐house B‐Spline algorithm for the prostate patient images. Both Demons and B‐Spline have been QAed through contour comparison. Self‐consistency is determined by using a DIR to generate a displacement vector field (DVF) between reference image and study image . The same DIR is used to generate . Additionally, our PIDVF generator is used to create . Back‐and‐forth mapping of a set of points (used as surrogates of contours) using and is compared to back‐and‐forth mapping performed with and . The Euclidean distances between the original unmapped points and the mapped points are used as a self‐consistency measure.ResultsTest results demonstrate that the consistency error observed in back‐and‐forth mappings can be reduced two to nine times in point mapping and 1.5 to three times in dose mapping when the PIDVF is used in place of the B‐Spline algorithm. These self‐consistency improvements are not affected by the exchanging of and . It is also demonstrated that differences between and can be used as a criteria to check the quality of the DVF.ConclusionsUse of DVF and its PIDVF will improve the self‐consistency of points, contour, and dose mappings in image guided adaptive therapy.