Japanese
TitleWhole body counter (plastic scintillators) による鉄吸収試験 - (1) その基礎的検討 -
Subtitle原著
Authors古松苣子*, 森下玲児**, 森田陸司*, 鳥塚莞爾***
Authors(kana)
Organization*京都大学医学部附属病院放射線部, **京都大学医学部附属病院第1内科, ***京都大学医学部附属病院放射線核医学科
Journal核医学
Volume16
Number8
Page1365-1371
Year/Month1979/11
Article原著
Publisher日本核医学会
Abstract「要旨」人体内で, 鉄は赤血球内のヘモグロビン中に最も多く存在する金属成分である. 鉄吸収試験が簡便にできるwhole body counterを用い, 分解能は劣るが感度の良いplastic scintillators(PS)で基礎検討を行なった. 59Fe線源0.11μCiから0.65μCiまでは直線関係があり, 最小検出感度は0.31nCiであった. PSは, 移動架台ベッドの下に設置されている. ベッド上では90%以上の感度が得られるが, 幾何学的条件, 高さの影響で感度は低下する. そこで, 体厚を補正するために仰臥位と腹臥位の両体位を測定し, その平均値を用いる. 放射性鉄0.4μCiとcarrier鉄として硫酸第一鉄の形で鉄量5mgを混和し. さらに, アスコルビン酸100mgを加えた水溶液とした試料を経口投与する. この値を100%値とし, この値に対する7日後の放射性鉄の体内残存率を鉄吸収率とした, この方法は, 簡便であると共に糞便採集や採血も必要なく, 優れた検査方法であると考える.
Practice臨床医学：一般
KeywordsWhole body counter, 59Fe-ferrous citrate, Iron absorption, Plastic scintillators, MDA
English
TitleThe Study of Iron Absorption Test using a Whole Body Counter with Plastic Scintillators - (1) Fundamental Studies -
SubtitleOriginal Articles
AuthorsChisako FURUMATSU*, Reiji MORISHITA**, Rikushi MORITA*, Kanji TORIZUKA***
Authors(kana)
Organization*The Central Clinical Radioisotope Division, **The First Department of Internal Medicine and ***Department of Radiology and Nuclear Medicine, Kyoto University School of Medicine
JournalThe Japanese Journal of nuclear medicine
Volume16
Number8
Page1365-1371
Year/Month1979/11
ArticleOriginal article
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
Abstract[Summary] This study reports the fundamental examination of iron absorption in human subjects using a whole body counter with plastic scintillators (PS). Four plastic scintillation probes were set under the bed. Each plastic scintillation probe contains a 500×500×150mm3 scintillator and four photomultiplier tubes. The counting rates of 59Fe-ferrous citrate from 0.11 to 0.65μCi were plotted and indicated a straight line relationship. However, the counting errors were observed over the range of 0.65μCi of 59Fe isotope according to this machinery property. Based on these findings, the administration dose of radioiron was determined as 0.4μCi. The minimum detectable amount of 59Fe point source was calculated as 0.31 nCi. The sensitivity was over 90 per cent on the bed of PS, but it decreased to about 70 per cent in air at 10 cm from the bed. Therefore, a subject was measured both in supine and prone position during a 300 seconds period. No significant decrease in count rate was found in subjects with various body weight. The measurement was made before, immediately after (100%), and again 7 and 14 days after the oral administration of 59Fe-ferrous citrate with carrier iron, about 5 mg as iron in the form of ferrous sulfate and aqueous solution with 100 mg of ascorbic acid. The subject was kept fasting at least for 2 hours after the administration of radioactive ferrous citrate. The retention percentages of 59Fe measured in each subject on the 7th and the 14th day, were almost the same. Therefore, the following formula is used to calculated the absorption of iron. Absorption(%)=cps day 7-background/cps day 1-background×100×a, where cps means counts per second and a is the correction factor for the radioactivity decay of 59Fe. This method is very simple and useful in comparison with other methods such as chemical balance, red cell radioiron incorporation as a measure of absorption and double isotope method for measuring iron absorption. There is no need to collect excreta or to draw blood sample. The amount of the radioactive iron required is the smallest and not hazardous to the human subject.
PracticeClinical medicine
KeywordsWhole body counter, 59Fe-ferrous citrate, Iron absorption, Plastic scintillators, MDA

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