Nucl Med Mol Imaging.  2009 Oct;43(5):443-450.

Preliminary Study on the Enhancement of Reconstruction Speed for Emission Computed Tomography Using Parallel Processing

• Park MJ
• Lee JS
• Kim SM
• Kang JY
• Lee DS
• Park KS

Abstract

PURPOSE
Conventional image reconstruction uses simplified physical models of projection. However, real physics, for example 3D reconstruction, takes too long time to process all the data in clinic and is unable in a common reconstruction machine because of the large memory for complex physical models. We suggest the realistic distributed memory model of fast-reconstruction using parallel processing on personal computers to enable large-scale technologies.
MATERIALS AND METHODS
The preliminary tests for the possibility on virtual manchines and various performance test on commercial super computer, Tachyon were performed. Expectation maximization algorithm with common 2D projection and realistic 3D line of response were tested. Since the process time was getting slower (max 6 times) after a certain iteration, optimization for compiler was performed to maximize the efficiency of parallelization.
RESULTS
Parallel processing of a program on multiple computers was available on Linux with MPICH and NFS. We verified that differences between parallel processed image and single processed image at the same iterations were under the significant digits of floating point number, about 6 bit. Double processors showed good efficiency (1.96 times) of parallel computing. Delay phenomenon was solved by vectorization method using SSE.
CONCLUSION
Through the study, realistic parallel computing system in clinic was established to be able to reconstruct by plenty of memory using the realistic physical models which was impossible to simplify

Keyword

Parallel computing; image reconstruction; optimization

MeSH Terms

Image Processing, Computer-Assisted
Isothiocyanates
Memory
Microcomputers
Tomography, Emission-Computed
Isothiocyanates