Tetsuya Horiuchi

Publications (2)1.22 Total impact

• Article: Design of a DICOM image-based program for estimating patient exposure dose in computed tomography.

  Shuji Yamamoto, Tetsuya Horiuchi, Junko Sekiguchi, Shigeo Wada, Mitsuru Komizu, Takami Yamaguchi
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  ABSTRACT: During the past decade, there has been a notable worldwide increase in the number of computed tomographic (CT) examinations. Since the radiation exposure to the patient during CT examinations is relatively high, it is important to optimize the dose so that it is set as low as possible but remains consistent with the required diagnostic image quality. Therefore we have developed a Digital Imaging and Communications in Medicine (DICOM) image-based program that calculates organ dose and effective dose values corresponding to tube current modulation. The values for primary radiation were derived from manufacturer specifications with international recommendations and from reference values (ICRP publication 60). Based on these values, organ doses can be computed by the program for arbitrary scan protocols in conventional and in spiral CT. In contrast to similar programs for CT dose assessment, our developed program can perform automatic extraction of the scan protocols from the DICOM tag. Users can easily reproduce and recalculate values by loading DICOM data without the requirement for time-consuming work. Additionally, further extensions are planned to our developed software.
  Technology and health care: official journal of the European Society for Engineering and Medicine 02/2007; 15(2):147-56.
• Article: Computer-simulation technique for low dose computed tomographic screening.

  Kouzou Hanai, Tetsuya Horiuchi, Junko Sekiguchi, Yoshihisa Muramatsu, Ryutaro Kakinuma, Noriyuki Moriyama, Ryosuke Tuchiiya, Noboru Niki
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  ABSTRACT: The purpose of this study is to assess the relative influence of noise and artifact in detecting lung nodules on low dose computed tomographic (CT) screening. We develop the computer-simulation technique that allows tube current simulation and virtual nodule insertion in any CT images. The tube current simulation uses a reduction model that adds random Gaussian noise distribution to existing projection data. The virtual nodules are generated using a dedicated CT simulation tool with same scanner geometry. The coefficient of the correlations between the contrast-to-noise ratio of the actual scan and simulated tube current images was 0.98. There was no difference in CT number between virtual nodules and actual nodules [t test results = 0.60, t50(0.01) = 2.70 at 10 mA] and the coefficient of the correlations of the image noise was 0.99. Our technique is useful for systematic evaluation of radiation dose reduction and structure visibility in low-dose CT screening.
  Journal of Computer Assisted Tomography 30(6):955-61. · 1.22 Impact Factor