High-speed image reconstruction based on CBP and Fourier inversion methods

Computed tomography (CT) image reconstruction algorithms such as convolution backprojection (CBP) and the Fourier inversion method (FIM) are highly compute intensive applications for today´s single processor systems. Shared memory multiprocessor systems are simple to implement. However the shared bus used to connect the processors to memory is a major bottleneck in a shared memory multiprocessor system. We have designed a hierarchical bus based system (HBBS) which solves the bus congestion problem by hierarchically increasing the number of buses. The architecture is truly expandable and it retains the simplicity of bus based systems. We have implemented the CBP and FIM algorithms on a HBBS, built using commercially available high performance floating point digital signal processor (DSP) devices. The HBBS is found to be efficient in executing the computed tomography (CT) image reconstruction algorithms. The motivation for this work is not to develop new algorithms, but to evaluate the relative performance of well known algorithms when applied to real practical architectures. The results show that an 8-node HBBS executes the CBP and FIM algorithms about 100 times faster compared to the execution time of CBP and FIM algorithms on an IBM 340 series Workstation