Author/Authors :
Oda، نويسنده , , Yasuyuki and Sato، نويسنده , , Eiichi and Abudurexiti، نويسنده , , Abulajiang and Hagiwara، نويسنده , , Osahiko and Osawa، نويسنده , , Akihiro and Matsukiyo، نويسنده , , Hiroshi and Enomoto، نويسنده , , Toshiyuki and Watanabe، نويسنده , , Manabu and Kusachi، نويسنده , , Shinya and Sugimura، نويسنده , , Shigeaki and Endo، نويسنده , , Haruyuki and Sato، نويسنده , , Shigehiro and Og، نويسنده ,
Abstract :
High-speed X-ray photon counting is useful for discriminating photon energy, and the counting can be used for constructing an X-ray computed tomography (CT) system. A photon-counting X-ray CT system consists of an X-ray generator, a turntable, an oscillation linear detector, a two-stage controller, a multipixel photon counter (MPPC) module, a 1.0 mm-thick crystal (scintillator) of YAP(Ce) (cerium-doped yttrium aluminum perovskite), a counter card (CC), and a personal computer (PC). Tomography is accomplished by repeating the linear scanning and the rotation of an object, and projection curves of the object are obtained by the linear scanning using the detector consisting of an MPPC module, the YAP(Ce), and a scan stage. The pulses of the event signal from the module are counted by the CC in conjunction with the PC. Because the lower level of the photon energy was roughly determined by a comparator in the module, the average photon energy of the X-ray spectra increased with increase in the lower-level voltage of the comparator at a constant tube voltage. The maximum count rate was approximately 3 Mcps (mega counts per second), and photon-counting CT was carried out.
Keywords :
YAP(Ce) scintillator , Oscillation linear detector , X-ray CT , Mcps photon counting , Energy-discrimination effect , Multipixel photon counter
