Author:
Shin Hubeom,Yoo Seungjun,Oh Seokwon,Lee Junho,Kim Ho Kyung
Abstract
Abstract
A sandwich-like double-layered detector can perform dual-energy imaging (DEI) using a
single x-ray exposure without object motion artifacts. The energy separation between measurements
obtained from the front and rear-detector layers can be tuned by introducing an x-ray
beam-attenuating material between them. However, the design of the interdetector filter
significantly influences dose efficiency by altering the number of x-ray photons reaching the
rear-detector layer within the sandwich detector. Since the sandwich detector typically
incorporates phosphors of differing thicknesses for its two detector layers, it exhibits a unique
spatial resolution characteristic in the reconstructed dual-energy (DE) images. To comprehensively
assess detector performance in terms of design (filter) and operation (reconstruction), we
established a framework that describes the dual-energy detective quantum efficiency (DE-DQE) using
linear-systems theory. The developed DE-DQE model was validated through comparison with
measurements. The agreement between the modulation-transfer functions was reasonable, and the
correspondence between noise-power spectra was excellent. This proposed DE-DQE concept is
universally applicable to any linearly operating DE system and holds a significant value in
enhancing the performance of sandwich detectors or ensuring their optimal operation.
Subject
Mathematical Physics,Instrumentation