◾ Implementation of Convolution Superposition Methods on a GPU

For both the TERMA computation and the superposition, ray tracing techniques are used to step through the voxel volumes to determine density and attenuation information from the patient’s CT data.

13.1.3Approximations Made in CPU-Based Implementations

In the central processing unit (CPU)-based algorithms, ray tracing was the dominant computation aecting the performance. Approximations were made to minimize the required computations for performance.