Japanese
Title局所脳血流測定の精度を左右する因子の検討 - HEADTOMEによるXe-133吸入法について -
Subtitle《原著》
Authors駒谷昭夫*, 高橋和栄*, 安久津徹*, 高梨俊保*, 菅井幸雄*, 山口昂一*
Authors(kana)
Organization*山形大学医学部放射線科
Journal核医学
Volume23
Number8
Page1019-1024
Year/Month1986/8
Article原著
Publisher日本核医学会
Abstract「要旨」: リング型SPECT (HEADTOME) を用い, Xe-133吸入法による3次元的局所脳血流 (rCBF) の測定精度を左右する因子について検討し, 良好なrCBF測定値の再現性を保持するための方法の確立を試みた. 吸入用Xeバッグ (spiro-bag) の容積は, 小さいほどXe-133濃度は高くなるが, 小さすぎるとrCBF値は過小評価される傾向があった. バッグ容積は0.8〜1.0lが最適であった. 吸入システムのバルブ切り換えタイミングを呼気終期に同期させた. 頭部データの収集開始時期は, Xe-133吸入開始後一定時間遅延する半固定式とした. 鼻腔内Xe-133による散乱線が少ないマウスピースの使用を原則とした. これらの改善策により, 健常者の平均rCBF値の標準偏差 (SD) は著明に小さくなった. さらに, partial volume effectで, 皮質の厚さや溝の形状により小局所のrCBF値は大きく変動するので, 小領域での精度には限界があり, 慎重な評価が必要と考えられた.
Practice臨床医学：一般
KeywordsRegional cerebral blood flow, Xe-133 inhalation method, HEADTOME, Dynamic SPECT.
English
TitleFactors Affecting Accuracy of Tomographic Measurement of rCBF by HEADTOME
SubtitleOriginal Articles
AuthorsAkio KOMATANI, Kazuei TAKAHASHI, Tohru AKUTSU, Toshiyasu TAKANASHI, Yukio SUGAI, Koichi YAMAGUCHI
Authors(kana)
OrganizationDepartment of Radiology, Yamagata University School of Medicine
JournalThe Japanese Journal of nuclear medicine
Volume23
Number8
Page1019-1024
Year/Month1986/8
ArticleOriginal article
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
Abstract[Summary] : Factors affecting accuracy of tomographic regional cerebral blood flow (rCBF) were investigated using a Xe-133 inhalation method and a dynamic single photon tomographic system ; HEADTOME. Several improvements were attempted in method and devices based on the investigation. To minimize statistical error, loss of xenon gas and an error in estimating air curve, volume of the spiro-bag was set properly (0.8-1.0 l) and a breath-synchronized control of the inhalation system was introduced. To avoid time mismatching between the tomographic head data and the respiratory air curve, the interval of their data acquisition starting was standerdized. For the inhalation of Xe-133, mouthpiece was superior to face-mask because of less effect by scattered radiation from the nasal cavity. Standard deviation of mean rCBF in normal volunteers was improved to 50.0+-1.7 ml/100g/min, from 51.2+-7.1 obtained before these improvements. Partial volume effect was also evaluated using simulated rCBF images calculated as a weighted mean value in each 32×32 pixels on trans-axial atlas of the normal brain. The rCBF value was noted to change with thickness or form of the cortex, sulci and ventricles.
PracticeClinical medicine
KeywordsRegional cerebral blood flow, Xe-133 inhalation method, HEADTOME, Dynamic SPECT.

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