Material Discriminated X-Ray CT System by Using New X-Ray Imager with Energy Discriminate Function
Toru Aoki, Takuya Nakashima, Hisashi Morii, Yoichiro Neo, Hidenori Mimura
Material discriminated X-ray CT system has been constructed by
using conventional X-ray tube (white X-ray source) and
photon-counting X-ray imager as an application with energy band
detection. We have already reported material identify X-ray CT
using K-shell edge method elsewhere. In this report the principle
of material discrimination was adapted the separation of
electron-density and atomic number from attenuation coefficient
mapping in X-ray CT reconstructed image in two wavelength
X-ray CT method using white X-ray source and energy
discriminated X-ray imager by using two monochrome X-ray
source method.
The measurement phantom was prepared as four kinds material
rods (Carbon(C), Iron(Fe), Copper(Cu), Titanium(Ti) rods of
3mm-diameter) inside an aluminum(Al) rod of 20mm-diameter.
We could observed material discriminated X-ray CT reconstructed
image, however, the discrimination properties were not good than
two monochrome X-ray CT method. This results was could be
explained because X-ray scattering, beam-hardening and so on
based on white X-ray source, which could not observe in two
monochrome X-ray CT method. However, since our developed
CdTe imager can be detect five energy-bands at the same time, we
can use multi-band analysis to decrease the least square error
margin. We will be able to obtain more high separation in atomic
number mapping in X-ray CT reconstructed image by using this
system. Full Text
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