Wei-Ben Wang, Presenter: Nothing to Disclose

Bo-Wen Xiao, Abstract Co-Author: Nothing to Disclose

Chien-Ju Lee, Abstract Co-Author: Nothing to Disclose

Ming Hua Yeh, Abstract Co-Author: Nothing to Disclose

Wen-Tung Wang, Abstract Co-Author: Nothing to Disclose

Ming-Huan Yang, Abstract Co-Author: Nothing to Disclose

A low dose, high resolution digital radiography sensor (DRS) is proposed herein. By using an electron-blocking electrode of poly(3,4-ethylene-dioxythiophene)-poly-(styrenesulfonate) (PEDOT) coupling with a 2T-1C pixel circuit, a 70-um pixel size of DRS is suitable for overcoming the drawbacks in conventional flat-panel X-ray detector, who suffer from limited resolution and sensitivity as the pixel size reduces to sub-100-μm as the prominent need for X-ray tomosynthesis, such as mammography.

Fig. 1 shows the pixel structure with 1-um thickness amorphous selenium (α-Se) as the conversion layer and PEDOT as the conducting electrode. By overlaying a-Se with 100% effective fill factor, the DRS could perform high resolution and low dose benefits. The blue-light is excited from phosphor with x-ray irradiating and then be absorbed by the a-Se. As shown in Fig. 2, the Se-containing photodiode consisted of an indium tin oxide (ITO) electrode, a Se layer and a PEDOT electrode.

The DRS with a flexible characteristic is demonstrated as shown in Fig. 3. The sensor could be still operated after a repeated bending test with 1.5 cm curvature radius and 2,000 bending times. The X-ray image obtained by full system is shown in Fig. 3 which the phantom image with circle profile could be observed. The image quality could be enhanced by implementing image processing algorithm in the future. Fig. 4 shows the current results in a Se-containing photodiode. As seen, by using PEDOT to be an electron-blocking electrode, the device exhibits higher current than that of an Ag-containing counterpart under an emission of a 470 nm blue light. Nevertheless, without any emission, the PEDOT-containing device possesses the lowest current among all.

The 70-um pixel size of high resolution DRS is fabricated. Under a low dose X-ray emission, a preliminary image of a phantom appearance could be obviously shown in the sensor. Flat-panel amplified pixel sensor array can be integrated into digital X-ray imaging systems for mammography, breast tomosythesis, fluoroscopy, dental imaging, and cone-beam CT applications.

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Wang, W, Xiao, B, Lee, C, Yeh, M, Wang, W, Yang, M, A Low Dose, High Resolution Digital Radiography Sensor by Using an Electron-Blocking Electrode.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006293.html