Development of a novel high-resolution direct conversion x-ray detector

Abstract

The development of a new high spatial resolution x-ray detector system is described. The prototype detector is based on a patented detector technology that utilizes selenium for the x-ray conversion material, charge storage capacitors, and a thin film transistor (TFT) array for reading out the charge image. This experimental detector consists of a 512 X 512 matrix with a pixel pitch of 70 microns. The selenium layer deposited on the TFT array is 250 microns thick. With a low absorption entrance window the system is optimized for an energy range of 10 - 30 keV, and is designed for applications that require high spatial resolution and low noise. This presentation describes the imaging performance of the detector using the DQE and MTF metrics. Example images of phantoms are shown. Previously, we demonstrated a practical flat-panel self-scanned digital radiography system based on amorphous selenium and TFT technology. This system is being used clinically for chest radiography and general musculoskeletal imaging, and in industrial applications. The current work demonstrates the feasibility of adapting this technology for applications requiring higher spatial resolution.