title: [Evaluation of the OS-EM parameter with automatic quantitative analysis for cerebral blood flow of the ECD tool].
abstract: 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.
authors: Kyushu Central Hospital of the Mutual Aid Association of Public School Teachers, Department of Radiology, Japan.
authors: Kimie
authors: K
authors: Asao
authors: Hitomi
authors: H
authors: Takeda
authors: Akihiro
authors: A
authors: Takaki
authors: Kazunori
authors: K
authors: Kawakami
authors: Satomi
authors: S
authors: Teraoka
mesh_terms: D000328:Adult; D000465:Algorithms; D002544:Cerebral Infarction / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006801:Humans; D008297:Male; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*