| Project/Area Number |
02670505
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | The Jikei University School of Medicine |
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Principal Investigator |
KAWAKAMI Kenji Dept. of Radiology, Associate Professor, 医学部, 助教授 (10056814)
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| Co-Investigator(Kenkyū-buntansha) |
MOCHIZUKI Sachio Dept. of Radiology, Professor, 医学部, 教授 (10056533)
森 豊 東京慈恵会医科大学, 放射線医学教室, 助手 (30166376)
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| Project Period (FY) |
1990 – 1993
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | ^<99m>Tc-technegas / Radio labelled ultrafine patricle / Ventilation / ^<133>Xe / ^<81m>Kr / ^<81>^mKr / テクネガス / ^<99m>TcO_4^ー存在比 / 生成量の時間的変化 / Hot Spot形成 / テクネガス肺内分布 / ^<99m>Tcーpertechnetate / 呼吸機能検査 |
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| Research Abstract |
^<133>Xe and ^<81m>Kr gas are used for the routine examination of ventilation, but these gases are not available for ambulant test, for example to pulmonary embolism. ^<99m>Tc-aerosol is also applied to ventilation study, but particle size of aerosol is too large to asess the ventilation. ^<99m>Tc-technegas (^<99m>Tc-gas) was developped to avoid such disadvantages.
^<99m>Tc-gas is produced by burning (2500ﾟC) ^<99m>Tc-pertechnetate in a carbon crucible in the technegas generator. Most particles of ^<99m>Tc-gas were 5-30nm in diameter as determined by electron microscopy.
About 37MBq of ^<99m>Tc-gas was inhaled in the lung by three times of deep inspiration, when 296MBq of ^<99m>Tc-pertechnetate was injected in the generator. Blood activity was appeared immediately after inhalation of ^<99m>Tc-gas and it was 0.2% of the inhaled dose/litter of blood after 2 hours. Urine activity was also increased after inhalation and cumulative dose was 4.96% of the in haled dose after 24 hrs. Biological half time of ^<99m>Tc-gas in the lung was 135 hrs and pulmonary image was stable even after 24 hrs. Radiation dose to the lung was 0.004 Gy/37MBq.
In a comparative study with radioactive inert gases (^<133>Xe, ^<81m>Kr), ^<99m>Tc-gas showed a similar distribution to the inert gas in most patients. Although the patients with obstructive lung disease showed hot spots in the entral airways, ^<99m>Tc-gas penetrated to the peripheral lung fields.
These results suggest that ^<99m>Tc-gas inhalation study is safe and useful method to evaluate ventilatory function even in patients with chonic obstructive pulmonary diseases.
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