Japanese Journal of Radiological Technology
Online ISSN : 1881-4883
Print ISSN : 0369-4305
ISSN-L : 0369-4305
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Volume 63, Issue 11
Displaying 1-14 of 14 articles from this issue
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Opening Article
Original
  • Reduction of Vascular Artifact on T1-weighted Images of the Brain by Using Three-dimensional Double IR Fast Spoiled Gradient Echo Recalled Acquisition in the Steady State (FSPGR) at 3.0 Tesla
    Yasuhiro Fujiwara, Tsuyoshi Matsuda, Yoshiyuki Ishimori, Isao Yamaguch ...
    2007 Volume 63 Issue 11 Pages 1239-1245
    Published: November 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1239
    JOURNAL FREE ACCESS
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    The purpose of this study was to decrease vascular artifacts caused by the in-flow effect in three-dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady state (3D IR FSPGR) at 3.0 Tesla. We developed 3D double IR FSPGR and investigated the signal characteristics of the new sequence. The 3D double IR FSPGR sequence uses two inversion pulses, the first for obtaining tissue contrast and the second for nulling vascular signal, which is applied at the time of the first IR period at the neck region. We have optimized scan parameters based on both phantom and in-vivo study. As a result, optimized parameters (1st TI=700 ms, 2nd TI=400 ms) successfully have produced much less vessel signal at reduction than conventional 3D IR FSPGR over a wide imaging range, while preserving the signal-to-noise ratio (SNR) and gray/white matter contrast. Moreover, the decreased artifact was also confirmed by visual inspection of the images obtained in vivo using those parameters. Thus, 3D double IR FSPGR was a useful sequence for the acquisition of T1-weighted images at 3.0 Tesla. (Article in Japanese)
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Clinical Technology
  • Creation of a Crystalline Lens Radiation Exposure Defense Cover and the Effect of Radiation Exposure Decrease on Neuro-interventions
    Toshio Take, Kaori Sato, Katsunori Kiuchi, Yasuo Nakazawa
    2007 Volume 63 Issue 11 Pages 1246-1252
    Published: November 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1246
    JOURNAL FREE ACCESS
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    A variety of radiation hazards resulting from interventional radiology (IVR) have been reported in recent years. Particularly affected are the skin and the crystalline lens, with their high radiation sensitivity. During neurological interventions, the radiological technologist should consider decreasing radiation exposure. We found exposure projections where the exposure dose became a radiation hazard for the crystalline lens, and examined an efficient method of cover for the exposure projections used for neurological interventions. The exposure projection for maximum crystalline lens radiation exposure was a lateral projection. In the crystalline lens the maximum exposure to radiation was on the X-ray tube side. The method of defense adopted was that of installing a lead plate of the appropriate shape on the surface of the X-ray tube collimator. In other exposure projections, this cover did not become a redundant shadow. With the cover that was created, the X-ray side crystalline lens lateral projection could be defended effectively. (Article in Japanese)
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Work in Progress
  • Sensitivity Characteristic That Uses Optical Filters in GafChromic Radiation Dosimetry
    Takeshi Kamomae, Yuuki Miyabe, Manabu Nakata, Shinsuke Yano, Takashi O ...
    2007 Volume 63 Issue 11 Pages 1253-1256
    Published: November 20, 2007
    Released on J-STAGE: January 10, 2008
    DOIhttps://doi.org/10.6009/jjrt.63.1253
    JOURNAL FREE ACCESS
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    GafChromic EBT film (GC-EBT) is lower in sensitivity than ready-pack film. The purpose of this study was to increase GC-EBT sensitivity by using band-pass filters and a polarized light filter. The filters were inserted between the GC-EBT and the scanner bed and digitized. We evaluated the sensitivity characteristic, amount of noise, and the dose corresponding to noise. When only the band-pass filter was inserted, a filter of transmission wavelength peak at 600 nm showed the maximum sensitivity. When a filter of 600 nm in transmission peak at wavelength was combined with a polarized light filter, sensitivity improved. There was no increase in the amount of noise according to the type of filter. The dose corresponding to noise increased as the quantity of light after passing through the filter decreased. When a suitable band-pass filter for the absorption peak of GC-EBT was used, it was suggested to be able to improve sensitivity without increasing noise. (Article in Japanese)
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The 34th Autumn Scientific Congress
Educational Lecture—Interpreting Medical Images for Radiological Technologists
Basic Lectures—The Image Processing Technology that You Should Learn on Examination
Clinical Technology Course
Series—Law and Medicine (6)
Report from the Scientific Research Group
Science Exchanges Committee Report
Science Exchanges Committee News
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