Comparison of image quality test methods in computed radiography

Abstract

Nowadays radiation dose and image quality optimisation is one of the major tasks of quality assurance in medical digital imaging. Because of broad dynamic range of the computed radiography (CR) systems an inappropriate technique could lead to unnecessary high exposure and potential harm of radiation dose to the patient while keeping a perfect image quality. Therefore there is a need to find out the reliable image quality parameters and optimisation methods which could guarantee an acceptable level of diagnostic performance of the images and at the same could be easily implemented in clinical environment. In the present work the threshold contrast-detail detectability (TCDD) evaluated with a CDRAD test phantom was studied at different tube potentials, with keeping constant detector entrance dose, phantom entrance surface dose (ESD) and time-current product (MAS) which corresponds to different strategies in dose-quality optimisation practice. The results of this work could be used for future research and development of constant CNR based method by combining it with the method of constant detector dose, enabling improvement of TCDD at lower tube potentials.