K-Edge Imaging Using Dual-Layer and Single-Layer Large Area Flat Panel Imagers

Dual-layer, or stacked, detectors reduce motion artifacts in combined x-ray images, such as k-edge images, by acquiring low-and high-energy signals simultaneously. In this work we constructed a prototype single pixel dual-layer detector using amorphous selenium (a-Se) as the conversion material based on the same technology used for commercial large area flat panel imagers. A cascaded detector model was used to model the detector and for comparison with the experimental measurements. The detector was demonstrated to obtain contrast-enhanced mammography signals using an iodinated contrast agent. The experimentally obtained contrast was compared with the model and good agreement was found demonstrating the feasibility of the dual-layer technology. For comparison purposes, a single-layer single pixel detector capable of k-edge imaging but prone to motion artifacts (acquiring low-and high-energy signals sequentially) was also studied.