TITLE:
Dual-Energy X-Ray Computed Tomography Scanner Using Two Different Energy-Selection Electronics and a Lutetium-Oxyorthosilicate Photomultiplier Detector
AUTHORS:
Osahiko Hagiwara, Eiichi Sato, Yasuyuki Oda, Satoshi Yamaguchi, Yuichi Sato, Hiroshi Matsukiyo, Toshiyuki Enomoto, Manabu Watanabe, Shinya Kusachi
KEYWORDS:
X-Ray Photon Counting, LSO-PMT Detector, Dual-Energy Counter, Energy-Dispersive CT, Gd-L-Edge CT, Gd-K-Edge CT
JOURNAL NAME:
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology,
Vol.6 No.3,
July
31,
2017
ABSTRACT: To obtain two kinds of tomograms at two different
X-ray energy ranges simultaneously, we have constructed a dual-energy X-ray
photon counter with a lutetium-oxyorthosilicate photomultiplier detector
system, three comparators, two
microcomputers, and two frequency-voltage converters. X-ray photons are
detected using the detector system, and the event pulses are input to three
comparators simultaneously to determine threshold energies. At a tube voltage
of 100 kV, the three threshold energies are 16, 35 and 52 keV, and two energy
ranges are 16 - 35 and 52 - 100 keV. X-ray photons
in the two ranges are counted using microcomputers, and the logical pulses from
the two microcomputers are input to two frequency-voltage converters. In
dual-energy computed tomography (CT), the tube voltage and current were 100 kV
and 0.29 mA, respectively. Two tomograms were obtained simultaneously at two
energy ranges. The energy ranges for gadolinium-L-edge and K-edge CT were 16 - 35 and 52 - 100 keV, respectively.
The maximum count rate of dual-energy CT was 105 kilocounts per second with
energies ranging from 16 to 100 keV, and the exposure time for tomography was
19.6 min.