Japanese
Titleシンチレーションカメラの感度不均一性に関する研究 第3報 不均一性のエネルギースペクトル依存性
Subtitle原著
Authors松本徹*
Authors(kana)
Organization*放射線医学総合研究所 臨床研究部
Journal核医学
Volume15
Number2
Page181-188
Year/Month1978/4
Article原著
Publisher日本核医学会
Abstract「I. 緒言」前報(第1, 2報)で行った, アンガー型シンチレーションカメラの感度不均一性に関する一連の実験により, 不均一性補正の成否を左右する重要な因子は, 光電ピークのゲイン(利得)とエネルギーウィンドー幅であることが示唆された. そこで本報では不均一性補正の効果および精度をより一層高めるために, ゲインとウィンドー幅の2因子を組み合せた時の不均一性について, さらに詳細に検討した. また, 臨床像を撮影する際に発生する散乱体からの散乱線を第3の因子として考慮した時の不均一性についても検討した. これより不均一性補正法の具体的な手順について, いくつかの知見を得たので報告する. 「II. 方法」本報では以下の2種の測定を行った. 解析の対象となったカメラは東芝製GCA 202型遅延線方式である. 「(a)カメラ自体の不均一性」コリメータを取りはずした状態で次の3つの因子の関数としてflood像を測定した.
Practice臨床医学：一般
KeywordsNon-uniformity, Delay-line camera, Energy spectrum.
English
TitleNon-Uniform Sensitivity of Delay-Line Scintillation Camera (No.3) ; Non-Uniformity as a Function of Energy Spectra
SubtitleOriginal Articles
AuthorsToru MATUMOTO
Authors(kana)
OrganizationClinical Division, National Institute of Radiological Sciences
JournalThe Japanese Journal of nuclear medicine
Volume15
Number2
Page181-188
Year/Month1978/4
ArticleOriginal article
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
Abstract[Summary]The non-uniformity of a delay-line scintillation camera (TOSHIBA GCA 202) were measured with a 99mTc point or plane source as a function of energy window width, gain-variations with or without scattering medium and with or without a collimator. The results were analyzed quantitatively by using the parameter of the extent of non-uniformity and differences in non-uniformity patterns previously reported. The results obtained are as follows. (1) In the case of the measurement with scattering medium and with a collimator, changes in non-uniformity of 99mTc flood image are significant compared with those without scattering medium and without a collimator. (2) The extent of non-uniformity of the images which are measured over the window from 20% to 80% with the scattering medium and the correlation coefficients between flood images are almost unchanged with window width even if the gain-variations are varied from -5% to +5% of the 99mTc photopeak. (3) Using the energy window less than 15%, small variations of the peak centering result in increasing of non-uniformity and the significant changes of the pattern of the flood image. (4) For above reasons, the flood image for correcting non-uniformity should be acquired at the settings approximating the energy spectrum seen in clinical studies with a collimator. (5) In the case of the window width less than 15%, correction of the non-uniformity is difficult. (6) But with respect to the window more than 20%, practical performance of non-uniformity correction is easy.
PracticeClinical medicine
KeywordsNon-uniformity, Delay-line camera, Energy spectrum.

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