| Japanese |
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| Title | 99mTc標識心筋血流製剤を用いた心筋SPECT画像への肝臓からの影響 |
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| Subtitle | 原著 |
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| Authors | 大西英雄*, 増田一孝*, 高田政彦**, 山本逸雄**, 森田陸司** |
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| Organization | *滋賀医科大学医学部附属病院放射線部, **滋賀医科大学医学部放射線科 |
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| Journal | 核医学 |
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| Volume | 35 |
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| Number | 6 |
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| Page | 375-383 |
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| Year/Month | 1998/7 |
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| Article | 原著 |
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| Publisher | 日本核医学会 |
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| Abstract | 「要旨」われわれは, 3検出器型ガンマカメラによる99mTc製剤心筋血流SPECTでの肝高集積の影響について, ファントムを用いて心筋および肝臓の線源強度(hepatic to cardiac activity ratio (HCR))および距離(hepato-cardiac distance (HCD))を変化させてSPECT画像再構成時に伴ういろいろな因子(フィルタ, 吸収補正, 散乱補正)について検討した. 散乱の影響は, HCRが大きくHCDが小さくなるにつれて下壁 > 側壁 > 前壁 > 中隔の順で大きくなり, 最大で35%増加を認めた. フィルタ処理は遮断周波数を高周波領域に設定し吸収および散乱補正を行うことで心筋部のカウントの変動が20%程度改善が見られた. しかし HCR = 3:1 以上で HCD = 0cm の場合においては画像再構成上でアーチファクトが生じた. フィルタサイズおよび次数を下げて, 吸収補正(Sorenson 法)を行うと欠損部のカウント値が15%ほど改善を認めた. |
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| Practice | 臨床医学：一般 |
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| Keywords | Quantitative myocardial SPECT, Hepatic to cardiac activity ratio, Scatter correction, Attenuation correction, Artifacts |
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| English |
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| Title | A Phantom Study for the Evaluation of the Effect of the High Uptake in the Liver on Technetium-99m Myocardial Perfusion SPECT Images |
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| Subtitle | Original Articles |
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| Authors | Hideo OHNISHI, Kazutaka MASUDA, Masahiko TAKADA, Itsuo YAMAMOTO, Rikushi MORITA |
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| Organization | Division of Nuclear Medicine and Department of Radiology, Shiga University of Medical Science |
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| Journal | The Japanese Journal of nuclear medicine |
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| Volume | 35 |
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| Number | 6 |
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| Page | 375-383 |
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| Year/Month | 1998/7 |
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| Article | Original article |
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| Publisher | THE JAPANESE SOCIETY OF NUCLEAR MEDICINE |
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| Abstract | The purpose of this study was to evaluate influences of the high hepatic uptake on parameters such as filtering, attenuation coefficient, and scatter correction at reconstructing of the myocardial SPECT images. Hepatic and cardiac spaces of a myocardial phantom (RH-2, Kyoto Kagaku), were filled with technetium-99m and a three-detector SPECT system (GCA 9300-DI, TOSHIBA) was used. The hepatic activity's influence was estimated from a qualitative percent regional scattering and the effects of attenuation and scatter correction were evaluated by a circumferential profile curve. Percent regional scattering increased in reverse to hepato-cardiac distance (HCD) and in proportion to hepatic to cardiac activity ratio (HCR). This tendency was observed the most significantly in the inferior region, followed by in the lateral, anterior and septal regions, declining in this order. An artifactual defect adjacent to the liver was observed when HCR is three and HCD is zero. However, when the Butterworth filter was used with small filtering-sizes and lower orders in combination with attenuation and scatter correction, the defects were decreased up to 15% at counts in the inferior region. This study showed that the hepatic to cardiac activity ratio, and the hepatocardiac distance should be considered for reconstruction of the SPECT images. |
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| Practice | Clinical medicine |
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| Keywords | Quantitative myocardial SPECT, Hepatic to cardiac activity ratio, Scatter correction, Attenuation correction, Artifacts |
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