The effect on dose accumulation accuracy of inverse-consistency and transitivity error reduced deformation maps
The effect on dose accumulation accuracy of inverse-consistency and transitivity error reduced deformation maps
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DOI：
10.1007/s13246-014-0262-0
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发表时间：
2014-06-01
影响因子：
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通讯作者：
Tome, Wolfgang A.
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文献类型：
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作者：
Hardcastle, Nicholas;Bender, Edward T.;Tome, Wolfgang A.
以前的研究表明，可变形图像配准（DIRs）通常会导致既非逆一致也非传递的变形图，并且如果使用不同的图像路径进行剂量积累，则基于这些变形图的剂量积累可能不一致。一种减少逆一致性和传递性误差的方法被证明可以产生更一致的剂量积累，而不管选择何种图像路径进行剂量积累。本研究探讨了为减少逆一致性和传递误差而处理的变形图对剂量累积精度的影响。分析了一组肺4DCT相位，由四幅图像组成，并在其上创建了剂量网格。手动跟踪75个相应解剖位置的剂量。在所有具有Demons衍生变形图的图像集之间进行剂量累积，并对变形图进行处理以减少逆一致性和传递性误差。然后将实际累积剂量与DIR累积剂量进行比较。考虑了两种剂量累积图像路径。后处理方法减少了逆一致性和传递性误差，对剂量累积精度的影响最小。其中一条途径的剂量积累准确性有统计学意义的提高，而另一条途径的差异无统计学意义。减少反向一致性和传递误差的后处理技术对剂量累积精度的影响是积极的，但影响很小。因此后处理技术在对剂量积累精度影响最小的情况下提高了剂量积累的一致性。
It has previously been shown that deformable image registrations (DIRs) often result in deformation maps that are neither inverse-consistent nor transitive, and that the dose accumulation based on these deformation maps can be inconsistent if different image pathways are used for dose accumulation. A method presented to reduce inverse consistency and transitivity errors has been shown to result in more consistent dose accumulation, regardless of the image pathway selected for dose accumulation. The present study investigates the effect on the dose accumulation accuracy of deformation maps processed to reduce inverse consistency and transitivity errors. A set of lung 4DCT phases were analysed, consisting of four images on which a dose grid was created. Dose to 75 corresponding anatomical locations was manually tracked. Dose accumulation was performed between all image sets with Demons derived deformation maps as well as deformation maps processed to reduce inverse consistency and transitivity errors. The ground truth accumulated dose was then compared with the accumulated dose derived from DIR. Two dose accumulation image pathways were considered. The post-processing method to reduce inverse consistency and transitivity errors had minimal effect on the dose accumulation accuracy. There was a statistically significant improvement in dose accumulation accuracy for one pathway, but for the other pathway there was no statistically significant difference. A post-processing technique to reduce inverse consistency and transitivity errors has a positive, yet minimal effect on the dose accumulation accuracy. Thus the post-processing technique improves consistency of dose accumulation with minimal effect on dose accumulation accuracy.