A new representation of intensity atlas for GPU-accelerated instance generation

Fast instance generation is a key requirement in atlas-based registration and other problems that need a large number of atlas instances. This paper describes a new method to represent and construct intensity atlases. Both geometry and intensity information are represented using B-spline deformation lattices; intensities are approximated using the multi-level B-spline approximation algorithm during model creation and the parallel computation capability of modern graphics processing units is used to accelerate the process of instance generation. Experiments with distal radius CTs show that, with a coefficients-to-voxels ratio of 0.16, intensities can be approximated up to an average accuracy of 2 ± 17 grey-levels (out of 3072 total grey-levels), and instances of resolution 256×256×200 can be produced in a rate of 25 instances per second with a GeForce GTX 285 video card, which is about 500 times performance improvement over the traditional method that uses plain CPU.