SPECTデータ評価用ディジタルファントムを用いた異なる処理装置間のOS-EM再構成アルゴリズムの比較

• Published in: 日本放射線技術学会雑誌 Vol. 64; no. 11; pp. 1361 - 1368
• Main Authors: 松友, 紀和, 古谷, 洋晃, 山尾, 太一郎, 西山, 徳深, 摺河, 健文, 杉野, 修一, 藤原, 秀司, 吉岡, 隆二
• Format: Journal Article
• Language: Japanese
• Published: 公益社団法人 日本放射線技術学会 2008
• Subjects: iteration; ordered subsets-expectation maximization (OS-EM); simulation phantom; single photon emission computed tomography (SPECT); subset
• ISSN: 0369-4305; 1881-4883
• DOI: 10.6009/jjrt.64.1361

Objective: In the OS-EM method, reconfigured images may be different among reconstruction image processors because the programs are highly arbitrary. The purpose of this study was to evaluate the difference in OS-EM algorithms among four different image processors using a digital phantom dedicated for SPECT data evaluation. The image processors used were GMS-5500A/PI (Toshiba), GENIE Xeleris (GE), e.soft (Siemens), and Odyssey FX (Shimadzu). Methods: Multiple images were reconstructed with OS-EM fluctuating the number of subsets and iterations. A region of interest (ROI) was placed on each image. The average counts, contrast, root mean square uncertainty (%RMSU), and normalized mean squared error (NMSE) of each ROI were calculated and compared with those of different image processors. Results: There was no significant difference in contrast among the algorithms. However, the average counts and (%RMSU were significantly different among algorithms as the number of updates increased. In addition, the minimums of NMSE were also different among algorithms. Conclusion: In the OS-EM method, careful evaluation is necessary when using multiple image processors in research studies on the standardization of nuclear medicine imaging or in clinical applications.