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Title: Quasimonochromatic x-ray computed tomography by the balanced filter method using a conventional x-ray source

Journal Article · · Medical Physics
DOI:https://doi.org/10.1118/1.1819553· OSTI ID:20634535
 [1]
  1. Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Niigata University, Niigata 951-8518 (Japan)

A quasimonochromatic x-ray computed tomography (CT) system utilizing balanced filters has recently been developed for acquiring quantitative CT images. This system consisted of basic components such as a conventional x-ray generator for radiography, a stage for mounting and rotating objects, and an x-ray line sensor camera. Metallic sheets of Er and Yb were used as the balanced filters for obtaining quasimonochromatic incident x rays that include the characteristic lines of the W K{alpha} doublet from a tungsten target. The mean energy and energy width of the quasimonochromatic x rays were determined to be 59.0 and 1.9 keV, respectively, from x-ray spectroscopic measurements using a high-purity Ge detector. The usefulness of the present x-ray CT system was demonstrated by obtaining spatial distributions of the linear attenuation coefficients of three selected samples--a 20 cm diameter cylindrical water phantom, a 3.5 cm diameter aluminum rod, and a human head phantom. The results clearly indicate that this apparatus is surprisingly effective for estimating the distribution of the linear attenuation coefficients without any correction of the beam-hardening effect. Thus, implementing the balanced filter method on an x-ray CT scanner has promise in producing highly quantitative CT images.

OSTI ID:
20634535
Journal Information:
Medical Physics, Vol. 31, Issue 12; Other Information: DOI: 10.1118/1.1819553; (c) 2004 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
Country of Publication:
United States
Language:
English