On developing B-spline registration algorithms for multi-core processors

• Published in: Physics in medicine & biology 2010-11, Vol.55 (21), p.6329-6351
• Main Authors: Shackleford, J A, Kandasamy, N, Sharp, G C
• Format: Article
• Language: English
• Subjects: Algorithms; Computer Graphics; Computers; Humans; Image Processing, Computer-Assisted - methods; Imaging, Three-Dimensional; Radiography, Thoracic; Reproducibility of Results; Software; Tomography, X-Ray Computed
• ISSN: 0031-9155; 1361-6560
• DOI: 10.1088/0031-9155/55/21/001

Spline-based deformable registration methods are quite popular within the medical-imaging community due to their flexibility and robustness. However, they require a large amount of computing time to obtain adequate results. This paper makes two contributions towards accelerating B-spline-based registration. First, we propose a grid-alignment scheme and associated data structures that greatly reduce the complexity of the registration algorithm. Based on this grid-alignment scheme, we then develop highly data parallel designs for B-spline registration within the stream-processing model, suitable for implementation on multi-core processors such as graphics processing units (GPUs). Particular attention is focused on an optimal method for performing analytic gradient computations in a data parallel fashion. CPU and GPU versions are validated for execution time and registration quality. Performance results on large images show that our GPU algorithm achieves a speedup of 15 times over the single-threaded CPU implementation whereas our multi-core CPU algorithm achieves a speedup of 8 times over the single-threaded implementation. The CPU and GPU versions achieve near-identical registration quality in terms of RMS differences between the generated vector fields.