Japanese Journal of Radiological Technology
Online ISSN : 1881-4883
Print ISSN : 0369-4305
ISSN-L : 0369-4305
Clinical Technology
Evaluation of the OS-EM Parameter with Automatic Quantitative Analysis for Cerebral Blood Flow of the ECD Tool
Kimie AsaoHitomi TakedaAkihiro TakakiKazunori KawakamiSatomi Teraoka
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Keywords: ML-EM, OS-EM, AQCEL, iteration, subset

2008 Volume 64 Issue 7 Pages 822-831


The parameters of reconstruction iteration and subset of the ordered subset expectation maximization (OS-EM) method have a great impact on image quality. In a cerebral blood flow (CBF) examination, it is critical to produce consistent results when analyzing clinical data. We evaluated the number of iterations and subset of the OS-EM method to stabilize image quality using a normal case and an infarction case. In the maximum likelihood expectation maximization (ML-EM) method, it was confirmed that the convergence of an infarction case was somewhat delayed compared with a normal case. With the OS-EM method, we have obtained the same results. Based on the rCBF values, we postulate that the iteration value is more than 8 and the subset value is less than 10. Furthermore, multiplying the iteration by a subset value ranging from 50 to 60 helps in stabilizing the quality of CBF imaging.

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© 2008 Japanese Society of Radiological Technology
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