1. Introduction To suggest a new type Dual X-ray imaging method, we set the optimum thickness of scintillator for low and high energy. Then, we measured the performance of filters to investigate previous study that is filters reduce X-ray hardening effect.
Material & Method We choose CsI(Tl) 0.16cm and 0.23cm thickness for low and high energy. That is referred in a previous paper. Then, to prove it, we measured the ADC value used by a CMOS sensor (Rad-icon Inc.). We choose filters that are Er 0.5mm for low energy, and Cu 0.8mm + Rh 0.4mm for high energy. These filters are chosen by simulation that conducted in previous research. To investigate the performance of filters, we used two method. 1. We measured the ADC value used by a CMOS sensor (Rad-icon Inc.). 2. We examined the exposure dose used by an ion chamber (Radcal Inc.). To measured the ADC value, we used DRZ series phosphor screens.
Experiment step 1. We examined the exposure dose without the filters and the collimator. 2. We applied the filters and the collimator, then, measured exposure dose.

2. 3. Result & conclusion
Figure Low energy(left) and High energy(right) ADC value at 100kVp when applied Er filter and Rh + Cu filter that used by DRZ screens.
Figure 1. Simulation result of the R value for the suggested K-edge method
Figure Low energy(left) that applied Er filter and High energy(right) that applied Rh + Cu filter ADC value at 100kVp that used by CsI(Tl) scintillator.