Share Email Print

Proceedings Paper

Initial characterization of a hybrid direct-indirect active matrix flat panel imager for digital radiography
Author(s): Adrian Howansky; Anastasiia Mishchenko; Sébastien Léveillé; Scott Dow; Jann Stavro; A. Goldan; James Scheuermann; A. R. Lubinsky; Wei Zhao
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Direct active matrix flat panel imagers (AMFPIs) using amorphous selenium (a-Se) offer high intrinsic spatial resolution but have limited x-ray quantum efficiency at general radiographic energies due to selenium’s low atomic number. Conversely, indirect AMFPIs using inorganic scintillators typically have superior x-ray quantum efficiency at these energies, but inferior spatial resolution and increased noise due to optical effects in the scintillator. These inherent limitations motivate alternative AMFPI designs to further improve detector xray sensitivity and signal-to-noise performance. Towards this goal, this work constructs and experimentally investigates the x-ray imaging performance of a novel direct-indirect prototype imager referred to as Hybrid AMFPI. The imager comprises a direct conversion a-Se layer that may be coupled to an interchangeable scintillator screen through a transparent blocking layer and bias electrode. In this direct-indirect “hybrid” configuration, a-Se serves as both an x-ray and optical sensor. Readout is performed by a thin-film transistor array with 85 μm pixel pitch. The prototype imager’s x-ray sensitivity, modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) are measured in a direct AMFPI configuration (i.e. a-Se alone) and in a Hybrid configuration under identical x-ray exposure conditions and the results are compared. Contrast-detail and spatial resolution phantoms are also imaged using direct, Hybrid and indirect AMFPI configurations under identical exposure conditions to evaluate differences in their imaging performance.

Paper Details

Date Published: 16 March 2020
PDF: 9 pages
Proc. SPIE 11312, Medical Imaging 2020: Physics of Medical Imaging, 113120X (16 March 2020); doi: 10.1117/12.2549893
Show Author Affiliations
Adrian Howansky, Stony Brook Univ. (United States)
Anastasiia Mishchenko, Analogic Canada Corp. (Canada)
Sébastien Léveillé, Analogic Canada Corp. (Canada)
Scott Dow, Stony Brook Univ. (United States)
Jann Stavro, Stony Brook Univ. (United States)
A. Goldan, Stony Brook Univ. (United States)
James Scheuermann, Stony Brook Univ. (United States)
A. R. Lubinsky, Stony Brook Univ. (United States)
Wei Zhao, Stony Brook Univ. (United States)

Published in SPIE Proceedings Vol. 11312:
Medical Imaging 2020: Physics of Medical Imaging
Guang-Hong Chen; Hilde Bosmans, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?