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High-Performance Computing is Radiation Cancer Treatment
Published in Theo C. Pilkington, Bruce Loftis, Joe F. Thompson, Savio L-Y. Woo, Thomas C. Palmer, Thomas F. Budinger, High-Performance Computing in Biomedical Research, 2020
Julian Rosenman, Timothy Cullip
The dose computation is based on a differential scatter air-ratio algorithm which separates the dose into primary and scatter portions. The original approach relied heavily on computationally intensive ray-casting techniques to determine patient depth, beam penumbra, and filter thickness along the rays from the source to each dose point (seeFigure 4a) The original code spent over 80% of its time in theray-casting algorithm. By replacing ray casting with a polygon scan conversion algorithm (common in the field of computer graphics), the depth information for all rays can be quickly precomputed into appropriate depth buffers. Once scan-converted, the information could then simply be looked up with bilinear interpolation for each ray (seeFigure 4b). This reduces theO(n3) ray casting toO(n2) scan conversion.
Three-Dimensional Visualization
Published in Diego Galar, Uday Kumar, Dammika Seneviratne, Robots, Drones, UAVs and UGVs for Operation and Maintenance, 2020
Diego Galar, Uday Kumar, Dammika Seneviratne
In volume rendering (as in surface rendering), voxel projection is substantially faster than ray casting. Figure 6.13 shows the CT knee dataset illustrated in Figure 6.14 rendered with this method. Three types of tissue—bone, fat, and soft tissue—are identified (Udupa, 1999).
Treatment verification and delivery
Published in Jing Cai, Joe Y. Chang, Fang-Fang Yin, Principles and Practice of Image-Guided Radiation Therapy of Lung Cancer, 2017
Ning Wen, Carri Glide-Hurst, Karen Chin Snyder, Mischa Hoogeman, Martina Descovich, Lei Ren, Indrin Chetty
2D/3D image registration can register an orthogonal pair of kV or MV x-ray images acquired prior or during treatment to DRRs rendered from the original CT set. DRRs are rendered iteratively from the CT data set until the optimal similarity measure is achieved [47]. Various methods have been proposed to expedite the rendering process, such as the ray casting method and the shear warp method [48]. Six DOF corrections can be applied for patient setup from the 2D/3D image registration. 2D/3D image registration has proven to be an accurate and reliable target localization method on various platforms including ExacTrac® [49], CyberKnife® [50], or On-Board Imager [51].
GPU ray casting method for visualizing 3D pipelines in a virtual globe
Published in International Journal of Digital Earth, 2019
Zhaocong Wu, Nan Wang, Jie Shao, Guohui Deng
With the improvement of GPU computing power, the ray casting method has been widely used in computer graphics, CAD, biological visualization, and other applications. It has been used in some previous studies for the visualization of molecular protein models (Lindow et al. 2010), city building models (Cignoni et al. 2007; Yoo 2013), terrain (Lee, Lee, and Shin 2016), and algebraic surfaces (Singh and Narayanan 2010).