Influence of the scattered X-rays on object sharpness of radiograph

Hidetaka Arimura, Takuji Date, Kaoru Morikawa, Hideaki Kubota, Masao Matsumoto, Hitoshi Kanamori

Research output: Contribution to journalConference article

1 Citation (Scopus)

Abstract

We investigated the influence of the scattered x-rays on the object sharpness of radiographs for tube voltages of 50 to 100 kV. For the purpose, using a phantom of the polymethyl methacrylate (PMMA) with an aluminum plate of low contrast object, the edge images including the blurs due to the x-ray focal spot, the screen-film system, and the scattered x-rays were produced. However, the shape of the overall modulation transfer function (MTF) derived from the edge image is considered not to be influenced by the scattered x-rays. As a result of comparing the overall MTFs with the product of the MTFs of the x-ray focal spot and the screen-film system, we found that the scattered x-rays gave different influence on the contrast at each spatial frequency for each tube voltage. To investigate the influence of the scattered x-ray on the overall MTF in detail, considering the MTF of the x-ray focal spot, we developed a method for determining the primary and scatter components of the overall MTF, whose components are proportional to the MTFs of the screen-film system and the scattered x-rays, respectively. Using the method, it was found that (1) the overall MTF depends on the MTF of scattered x-rays as well as the MTFs of the focal spot and screen-film system; and (2) at frequencies near 0 mm-1, the influence of the blur due to the scattered x-rays on the object sharpness was greater than that occurred in the intensifying screen and increased with the tube voltage.

Original languageEnglish
Pages (from-to)506-513
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume3977
Publication statusPublished - Jan 1 2000
Externally publishedYes
EventMedical Imaging 2000: Physics of Medical Imaging - San Diego, CA, USA
Duration: Feb 13 2000Feb 15 2000

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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