Modeling the Performance Characteristics of Computed Radiography (CR) Systems

Abstract

Computed radiography (CR) using storage phosphors is widely used in digital radiography and mammography. A cascaded linear systems approach wherein several parameter values were estimated using Monte Carlo methods was used to model the image formation process of a single-side read ‘flying spot’ CR system using a granular phosphor. Objective image quality metrics such as modulation transfer function (MTF) and detective quantum efficiency (DQE) were determined using this model and show good agreement with published empirical data. A model such as that addressed in this work could allow for improved understanding of the effect of storage phosphor physical properties and CR reader parameters on objective image quality metrics for existing and evolving CR systems.

Image simulation and a model of noise power spectra across a range of mammographic beam qualities

“…Some authors have built an entirely theoretical model of detectors to show how detector composition and thickness affect image quality. [19][20][21] The models examine not only primary quantum noise but estimate the excess noise sources such as the Lubberts effect. 22 These models have been used in examining the effect of changes in the design parameters of detectors such as detector thickness and material.…”

Scintillator performance considerations for dedicated breast computed tomography

“…For the specified breast dimensions, imaging geometry and acquisition parameters, the air kerma at isocenter in each projection view and consequently the fluence incident on the breast were determined. The x-ray fluence transmitted through the breast was propagated through the imaging chain using a validated parallel-cascaded systems model [27,30,32,33] that accounted for characteristic x-ray emission and reabsorption within the scintillator. The model was used to obtain the objective imaging metrics in projection space such as modulation transfer function (MTF), noise power spectrum (NPS), noise-equivalent quanta (NEQ), and detective quantum efficiency (DQE) in spatial frequency (Fourier) domain [33].…”

Simulating radiographic inspections with imaging plates

“…In the previous works, Vedantham and Karellas have developed a complete (from X-ray exposure to digital readout) analytic CR model to analyze the propagation of system performance factor, such as detective quantum efficiency (DQE) and modulation transfer function (MTF), during the image formation process [6]. In their approach, the X-ray scattering effect is considered negligible.…”