Multi‐core accelerated simulation of x‐ray projection based on Unigraphics NX model

Abstract

In computed tomography, the simulation of x‐ray projection is very important for developing and evaluating image reconstruction methods. Currently, the computer aided design models have been used for projection simulation. Compared with the stereolithographic model, the Unigraphics NX (UG) model can describe complex objects with multiple materials. However, calculating the intersection of a ray with a UG model can only be performed by an internal function, which greatly decreases the efficiency of the projection simulation. Therefore, we propose a fast method for projection simulation based on multi‐core. In this method, we use the internal function to calculate the intersection points and the corresponding face normal vectors for a ray. By computing the dot product between the direction vector of the ray and the face normal vectors, we can determine the entry and exit point pairs, and further obtain the simulation projection. On this basis, the projection simulation tasks are evenly decomposed to multiple processes. Then, we invoke these processes by multi‐thread in a main process, and realize parallel implementation of the projection simulation. Numerical experiments demonstrate the accuracy and effectiveness of the method, and we can obtain nearly linear speedup of the multi‐core acceleration.