Development of a selenium-based flat-panel detector for real-time radiography and fluoroscopy

Flat-panel detector (FPD) is the driving force for realizing the next generation of x-ray systems. The purpose of this study was to develop a selenium-based FPD for both radiography and fluoroscopy. The detector uses amorphous selenium (a-Se) and a thin-film transistor (TFT) array. The simple construction of the a-Se layer permits real-time readout. The unique response characteristics of the FPD, which can be saturated over permitted x-ray doses, are provided by the TET structure. Our prototype FPD was designed to acquire images at 30 frames per second (fps). A high modulation transfer factor was obtained: 0.63 at 2.0 Lp/mm. Sequential fluoroscopic images were acquired at up to 30 fps. The linear characteristics of the detector covered the commonly employed range of clinical exposure dose. Less than 1.5 % image lag was measured at 30 fps.