In this research, we develop an efficient intensity-based rigid 2D-3D image registration method. We implement the resulting algorithm using the RapidMind Multi-core Development Platform to exploit the highly parallel multi-core architecture of graphics processing units (GPUs). We use a ray casting algorithm to generate the digitally reconstructed radiographs (DRRs) on GPUs and efficiently reduce the complexity of DRR construction. The registration optimization problem is solved by the Gauss-Newton method. To fully exploit the multi-core parallelism, we implement almost the entire registration process in parallel by RapidMind. Numerical results are presented to demonstrate the efficiency of our method.
Image resolution | C++ | RapidMind | |
16x16x16 | Time per iteration (sec) | 0.015 | 0.138 |
Iteration | 6 | 6 | |
32x32x32 | Time per iteration (sec) | 0.200 | 0.186 |
Iteration | 5 | 5 | |
64x64x64 | Time per iteration (sec) | 5.308 | 0.262 |
Iteration | 5 | 5 | |
128x128x128 | Time per iteration (sec) | 56.720 | 0.400 |
Iteration | 6 | 6 |
Portal image parameters | C++ | RapidMind | |
Rotations: (2, 2, 2) Translations: (2mm, 2mm, 2mm) | Total time (sec) | 168.16 | 1.75 |
Iteration | 5 | 5 | |
Rotations: (4, 4, 4) Translations: (4mm, 4mm, 4mm) | Time per iteration (sec) | 263.30 | 2.70 |
Iteration | 8 | 8 | |
Rotations: (6, 6, 6) Translations: (6mm, 6mm, 6mm) | Time per iteration (sec) | 371.39 | 3.65 |
Iteration | 11 | 11 |