Resolution properties of a computed radiographic system

Hiroshi Fujita, Junji Morishita, Katsuhiko Ueda, Du Yih Tsai, Akiyoshi Ohtsuka, Tsuyoshi Fujikawa

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


The analysis of spatial-resolution properties in terms of the modulation transfer function (MTF) has been presented in a computed radiographic (CR) system (FCR-101) with the photostimulable-phosphor plate (imaging plate, IP). The newly devised method of determining the presampling MTF which includes the x-ray detector (IP) unsharpness and the unsharpness of the sampling aperture is described in which an image of a slightly-angulated lead slit relative to a horizontal or vertical direction is employed. The IP MTFs as an analog MTF in the system, the presampling MTFs for different types of IPs, different sampling distances, different versions of IPs, simultaneous multisection tomography and magnification radiography, and the laser-printer MTFs as display MTF are measured and shown. The effective sampling aperture MTFs calculated indicate that the noticeable degradation of resolution occurs at the stage of image data sampling. The usefulness of the magnification technique for mammography and bone radiography is demonstrated. It is shown that both of the digital MTF and the overall MTF are difficult to use for general purpose due to the aliasing artifacts. The effect of glare on the contrast is also characterized by lead-disk method. The glare fraction is found to be approximately 6.5%.

Original languageEnglish
Pages (from-to)263-275
Number of pages13
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - May 1 1989
Externally publishedYes

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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