RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 24 , Issue 5
Showing 1-15 articles out of 15 articles from the selected issue
  • Takahiko AOYAMA, Kazuaki KAMATA, Yoshimitsu KOBAYASHI, Tamaki WATANABE
    1975 Volume 24 Issue 5 Pages 305-311
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    In this paper the dependency of sparking voltage of a self-triggering spark chamber on the specific ionization of incident particles and its application are described.
    The chamber was composed of an electroconductive glass anode and a gauze cathode with gap length d of 0.5 cm. The filling gas, a mixture of argon and a few per cent of ethylalcohol vapor, was used with pressure p of 300-760 Torr at room temperature. DC voltage was supplied on the anode through a quenching resistor. Spark pulses were taken out of the cathode and counted.
    Using a RaDEF source, α- and β-rays, their specific ionizations are largely different, were shot into the gap nearly perpendicularly to the electrodes. Two step plateaus appeared on the curve of counting rate vs. applied voltage. It was found that the sparking voltage in the case of α-ray incidence was decreased more than 10% compared with that in the case of β-ray incidence. Setting the DC voltage to make sparks occur only in the case of α-ray incidence, it was possible to obtain an α-ray source image from an α- and β-ray mixing source.
    In order to discuss theoretically about these results, an equation of sparking voltage Vs as a function of specific ionization N0was delived using the streamer theory of spark. Considering the reduction of Townsend's first ionization coefficient due to the space charge effect of an electron avalanche, the following was obtained.
    Vs≅√C+1/2lnVs-lnNOpd/A/√1-2pd/AVs/(Vs-Bpd)3+Bpd
    where A, B and C are constants which depend on the sort of the gas. From this equation the sparking voltage V for α-ray incidence and that Vfor β-ray incidence were calculated. Theoretical values of the decreasing rate of sparking voltage, (V-V) /Vand experimental values agreed well. Then it was shown that the decrease of sparking voltage was well explained with the difference of specific ionization of incident particles.
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  • Yatsuka MATSUDA, Tetsuo MAMURO
    1975 Volume 24 Issue 5 Pages 312-317
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    An analytical technique for the simultaneous measurements of the atmospheric concentrations of SO2 gas and sulphur absorbed by aerosol particles has been developed. Aerosol particles are collected on membrane filter and at the same time SO2 gas is captured on alkali impregnated filter. The sulphur content in each filter is measured by an energy dispersive X-ray fluorescence spectrometer consisting of a Si (Li) semiconductor detector connected to a multi-channel pulse height analyzer and an excitation source of 55Fe. Two methods are acceptable for the determination of the sulphur content in impregnated filter by X-ray fluorescence analysis. In the first method X-ray fluorescence analysis is made after the collected sulphur has diffused and distributed uniformly enough throughout filter, and in the second method X-ray fluorescence analysis has to be finished before the diffusion of the collected sulphur becomes appreciable.
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  • Ieaki UEMURA, Hironori MURAKAMI
    1975 Volume 24 Issue 5 Pages 318-321
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    FI 6934 (Caerulein) is a biologically active decapeptide extracted from the skin of Australian amphibians (Hyla caerulea) . For metabolic study of FI 6934, we have attempted to label the sulfo group of tyrosine moiety of FI 6934 with 35S. The starting decapeptide was sulfonated with an exccess of pyridine-N-sulfonate-35S, and the 35S-labeled peptide resulted was deacetylated by hydrolysis in alkaline, purified by paper chromatography to obtained radio chemically pure 35S-labeled FI 6934. The 35S-labeled FI 6934 was identified as a standard FI 6934 in physiological activity to contract guinea pig gallbladders.
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  • Koichi ISHIGAMI, Masanori MATSUMOTO
    1975 Volume 24 Issue 5 Pages 322-326
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The fundamental study of quantitative scale display of the organ uptake with γ-camera was performed in special respect of the thyroid gland and the pancreas.
    As one of the measurements on certain dimension of the organ, an optical progression outside the digital image was expressed, and was subjected to the quantitative scale with the use of the threshold level. And a rather satisfactory correlation was clinically obtaind between the scale display and the thyroidal 131I uptake.
    For the purpose of revising the above scale display, the organ depth was measured with RI by the aid of the phantom. Then the pancreas depth was determined by the count rate ratio curve of 140 and 270 keV peak of 75Se energies. However, the body background and the radioactive rays from the neighboring organs interferred this curve.
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  • Ikuro ANZAI, Masanori KANNO, Tomomitsu HIGASHI, Hideo KATO, Koh NAKAMU ...
    1975 Volume 24 Issue 5 Pages 327-331
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The whole body absorbed dose of the patient administered 57Co-Bleomycin for tumor diagnosis was estimated in accordance with the MIRD Committee method. The whole body retention function was well described by the two component exponential model. The effective half-lives were several hours in the initial rapidly decreasing phase and 2-3 months in the successive slow phase. The accumulated whole body absorbed dose following intravenous administration of 1mCi of 57Co-Bleomycin was calculated to be approximately 3 rads, more than 90% of which was delivered in the first one year following injection. It was also revealed that no less than 99% of the dose was brought by the slow phase component, which indicated the importance of obtaining slow phase excretion date for dose estimation concerning the newly applied radiosubstances, irrespective of necessity or unneeessity for the diagnosis itself. Relatively high level of deposition was observed in the liver of a male patient of 82 years old who died of lung cancer 15 days after intravenous injection of 57Co-Bleomycin.
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  • Akira ISHIBASHI, Katsumi ISHII, Kazushige YODA, Shozo HASHIMOTO
    1975 Volume 24 Issue 5 Pages 332-339
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The scintillation photographs of the kidneys of 35 cases were taken using 99mTc-EDTA. The photographs were compared with those taken using 99mTc-DTPA and 131I-hippuran. In normal cases, 99mTc-EDTA which is excreted most slowly serves to take best the pictures of the parenchyma and the pelvis of the kidney. Being a 99mTc-labelled compound with a short half life time and being administrable at a substantial dose of 2-4 mCi, 99mTc-EDTA provides an advantage to take continuous pictures of the blood vessel phase.
    This reagent can, therefore, help take a clear picture of the congestion site of the renal infarct. However, the renal dynamic test using EDTA or DTPA is difficult to catch such delicate changes as very slight rejection of the transplanted kidney or as very slight disturbance of the kidney parenchyma. In this respect, 131I-hippuran is superior to EDTA and DTPA. In obstructive disorders of the kidney, there was no remarkable difference among these three reagents.
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  • Hiyoshimaru OYAMADA
    1975 Volume 24 Issue 5 Pages 340-344
    Published: May 15, 1975
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    “scintigram Viewer”, SVO-1, is designed for reading the scintigram films by enhancing contrast of the pictures. This is composed of a light source, AKAI CVC-150 T V camera (with a zoom lens, Fu jinon TV·Z, f: 2), AKAI VCS-150 camera control unit and color TV (Sony, Trinitron CVM-1840) .
    The light source is set in a box which has a side-window where the scintigram film is set. The light coming through the film is caught by TV camera where red and blue lights are separated, leaving green light not affected. These lights are then sent to AKAI VCS-150 where the gains for red and blue can be adjusted to desirable color as the operator likes for display.
    After these manual processings, the scintigram film is shown on the color TV. The contrast enhancement can be done by adjusting either picture control on the TV panel or diaphragm of TV camera/or both, and the defocusing can be easily done by changing the focus of the lens. Because the TV camera has a zoom lens as mentioned above, either whole picture or enlarged picture of one area on the film can be displayed.
    Initially, the author designed this machine to find out cold areas which were easily overlooked by the ordinary manner on the original films. However, after examining many scintigram films by this technique it was found that the search for the hot areas was more suitable with this machine and the whole body bone scintigram was the best so far. For example, the metastatic bone lesion which is not definite on the original scintigram by nacked eyes can be easily pointed out on the color T V after the abovementioned processings.
    Now, this machine is working very well and is an important accessory for our daily work.
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  • Masakatsu TEZUKA, Rensuke GOTO, Osamu TAMEMASA
    1975 Volume 24 Issue 5 Pages 345-348
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Keisuke KANAO, Yoshihiko MATSUYUKI
    1975 Volume 24 Issue 5 Pages 349-351
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Kikuo MACHIDA, Akira AKAIKE, Sanshin HAYASHI, Tsutomu WATARI, Hiroshi ...
    1975 Volume 24 Issue 5 Pages 352-353
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Yoshihiko YAMAGISHI, Kazuyoshi HONDA, Hideyuki WATANABE, Shinobu SHIIB ...
    1975 Volume 24 Issue 5 Pages 354-356
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Hirotoshi SANO
    1975 Volume 24 Issue 5 Pages 357-364
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Yosihiko KASIDA
    1975 Volume 24 Issue 5 Pages 365-366
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Akiyo SHIGEMATSU
    1975 Volume 24 Issue 5 Pages 367-377
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • 1975 Volume 24 Issue 5 Pages A1531-A1084
    Published: May 15, 1975
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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