병렬 연산을 이용한 방출 단층 영상의 재구성 속도향상 기초연구 (Preliminary Study on the Enhancement of Reconstruction Speed for Emission Computed Tomography Using Parallel Processing) |
Author |
박민재1,3, 이재성1,2,3, 김수미1,4, 강지연1, 이동수1,4, 박광석3, |
Min Jae Park, M.S.1,3, Jae Sung Lee, Ph.D.1,2,3, Soo Mee Kim, M.S.1,4, Ji Yeon Kang, M.D.1, Dong Soo Lee, M.D.1,4, and Kwang Suk Park, Ph.D.3 |
Affiliation |
서울대학교 의과대학 핵의학교실1, 의생명과학과2, 서울대학교 대학원 의용생체공학 협동과정3, 서울대학교 대학원 방사선응용생명과학 협동과정4 Departments of 1Nuclear Medicine and 2Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea; 3Interdisciplinary Program, Biomedical Engineering Major, Graduate School of Seoul National University, Seoul, Korea; 4Interdisciplinar |
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 |
Full text Article |
10_박민재.pdf
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