3D shape reconstruction of lumbar vertebra from two X-ray images and a CT model
3D shape reconstruction of lumbar vertebra from two X-ray images and a CT model
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DOI：
10.1109/jas.2019.1911528
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发表时间：
2020-07-01
影响因子：
11.8
通讯作者：
He, Huiguang
中科院分区：
文献类型：
--
作者：
Fang, Longwei;Wang, Zuowei;He, Huiguang
从双平面x射线图像中重建三维解剖结构是一个具有挑战性的课题。传统的基于弹性模型的方法是通过变形弹性网格上的控制点来重建三维形状。然而，由于有限的控制点只分布在弹性网格的边缘，重构的形状并不光滑。另外，基于统计模型的方法，包括基于形状模型和基于强度模型的方法，由于它们的平滑重建而被引入。然而，两者都有局限性。基于形状模型的方法只考虑边界轮廓，导致丢失有效的强度信息。对于基于强度的方法，由于每次迭代都需要计算强度分布，计算速度较慢。为了解决这些问题，我们提出了一种利用x射线图像和标本CT数据的新的重建方法。具体来说，CT数据提供了椎体的形状网格和强度模型。强度模型用于从x射线图像中生成变形场，形状模型用于应用计算的变形场生成患者特定模型。在公共合成数据集和临床数据集上的实验表明，平均重构误差分别为1.1 mm和1.2 mm。平均重建时间为3分钟。
Structure reconstruction of 3D anatomy from biplanar X-ray images is a challenging topic. Traditionally, the elastic-model-based method was used to reconstruct 3D shapes by deforming the control points on the elastic mesh. However, the reconstructed shape is not smooth because the limited control points are only distributed on the edge of the elastic mesh. Alternatively, statistical-model-based methods, which include shape-model-based and intensity-model-based methods, are introduced due to their smooth reconstruction. However, both suffer from limitations. With the shape-model-based method, only the boundary profile is considered, leading to the loss of valid intensity information. For the intensity-based-method, the computation speed is slow because it needs to calculate the intensity distribution in each iteration. To address these issues, we propose a new reconstruction method using X-ray images and a specimen's CT data. Specifically, the CT data provides both the shape mesh and the intensity model of the vertebra. Intensity model is used to generate the deformation field from X-ray images, while the shape model is used to generate the patient specific model by applying the calculated deformation field. Experiments on the public synthetic dataset and clinical dataset show that the average reconstruction errors are 1.1 mm and 1.2 mm, separately. The average reconstruction time is 3 minutes.