Physical Imaging Properties and Low-contrast Performance of a Newly Developed Flat-panel Digital Radiographic System

Abstract

We investigated the clinical usefulness of a newly developed flat-panel detector (FPD) system by comparing its physical imaging properties and low-contrast detectability with those of a current FPD system. The newly developed CsI-based indirect FPD (Canon, CXDI-40C) and current Gd(2)O(2)S-based FPD (Canon CXDI-11) systems were used. Characteristic curves, resolution properties, radiographic noise, detective quantum efficiencies (DQEs) and low-contrast detectability for both systems were measured. The new FPD system showed considerably lower noise levels than those of the current FPD system. DQE (0) s of the new and current FPD systems were 75% and 35%, respectively. Observer performance tests of the contrast-detail (C-D) phantom indicated that the new FPD system can significantly improve low-contrast performance over that obtainable with the current FPD system under the same conditions of exposure. The new FPD system provided approximately 50% reduction in exposure while providing comparable detectability. The newly developed FPD system provides radiographic images with excellent inherent physical image quality and low-contrast performance.

Characterization of a clinical unit for digital radiography based on irradiation side sampling technology

“…This was expected and indeed had already been reported in the literature. 31 In particular, for the low-energy beams, the improvement of the CsI is clear and the noise for the GOS system can go up by a factor 2 greater than that found for CsI. On the contrary, at high energies the NPS of the GOS is shown to be comparable or even lower at high spatial frequencies.…”