32—Detector局所脳循環測定装置（Meditronic）の構成とその使用経験

COMPOSITION OF THE 32-DETECTOR rCBF SYSTEM (MEDITRONIC) AND EXPERIENCE OF USING IT

I．はじめに

　近年，¹³³Xeクリアランス法による局所脳循環（rCBF）測定法の確立^4,8〜10）と進歩に伴い，種々の脳病態生理に関する知見が報告されている^3,10）。

　とくにcomputer技術の導入とdetector数の増加により，rCBFの微細な変動を敏速に処理することが可能となつた^7,14）。著者等はmicrocomputerを使用した固定プログラムを有する32チャンネルrCBF測定装置（RCBF−322,Meditronic,Denmark）を用いて，神経学的脱落症状を認めない症例のrCBFを閉眼静止時に2回連続して測定し，木装置の再現性の検討を行なつた。rCBF測定法の普及に伴いこれらの結果は，種々のrCBFと比較する上でも重要であると考えられるので，本装置の構成，ソフトウエアの概略およびrCBF測定法の理論的，実際的問題点について若干の考察を加えて報告する。

Regional cerebral blood flow (rCBF) was measured in patients with no neurological deficit and no ab-normal findings of cerebral angiograms except aneurysm itself with Xenon-133 injection technique by using the computerized 32-detector rCBF system (rCBF-322, Meditronic, Denmark). This system consists of a 32-detector head with a concave surface and a 32 pulse height analyser and analog-digital ratemeter as the accumulator connected to display units with an oscilloscope for 32 clearance curves and also a microcomputer programmed for calculating the rCBF initial with the initial slope analysis, for calculating the rCBF 10 with the height-over-area method and the rCBF gray, rCBF white, weight gray and weight white with the SHAM method.

The results obtained were as follows: 1) The mean value and SD of rCBF initial was 58.4±6.2 ml/100 g brain/min; rCBF 10, 50.6±5.0 ml/100 g brain/min ; rCBF gray, 78.0±14.0 ml/100 g brain/ min ; rCBF white, 22.1 ± 6.6 ml/100 g brain/min ; weight gray, 49.0±3.7% ; weight white. 51.0± 3.7%. These data should be considered normal values as reported also by others. 2) Reproduci-bilities were estimated by measuring twice the rCBF initial and the rCBF 10 at rest with closed eyes. The reproducibilities of the rCBF initial eyes 13. 55% (P<0.05) and one of the rCBF 10 was 8.85% (P<0.05).

It was concluded that this system should be widely used for measuring the rCBF in patients with various cerebral diseases.