Optimisation strategies introduced for CR at health care centres in Estonia

Abstract

In recent years, starting from 2001, conventional film-screen radiography has been rapidly replaced by digital (mostly by computed radiography, CR) techniques in Estonia. New strategies for optimisation and quality assurance for digital radiography have been introduced by the DIMOND III and SENTINEL partners recently. It includes consideration to diagnostic requirements of a given clinical situation, but also objectivation and standardisation of image quality, e.g. using CDRAD test phantom, and constancy testing. The aim of this work is to evaluate the performance of an automatic exposure control (AEC) at different sensitivities when used with the Fujifilm CR system. Image quality, using threshold contrast-detail detectability (TCDD) and signal-to-noise ratio squared related to dose (SNR2/D), was also investigated for different sensitivities and tube potential values for this combination. Based on the image evaluation data, optimum speed modes for the organ programme settings have been proposed.

A novel method for comparing radiation dose and image quality, between and within different x-ray units in a series of hospitals

“…Our FOM can be useful for optimisation of the x-ray units and imaging protocols. On the other hand, from the reviewed literature on optimisation, it was found that the common FOM formulas that are utilised with LCD detectability and a CD phantom such as CDRAD 2.0 phantom used are FOM=SNR 2 /dose and FOM=CNR 2 /dose [36][37][38]. However, these two formulas use SNR and CNR as a metric which are self-limiting since, as stated, they do not take into account the object size (pathology or anatomical structure) during IQ evaluation [39] which is considered a limitation in these two measures of IQ.…”