Analysis of observer performance in detecting radiographic signals using ROC approach

Analysis in terms of the receiver operating characteristic curve (ROC) has recently been applied to evaluate medical imaging technique. This paper presents a brief description of ROC and shows how it provides a measure of diagnostic observer performance. Test radiographs of 5 by 5 cm film, were shown to 4 observers. Radiographs containing 2 mm lucite bead plus noise, or noise only, were obtained with 3 film-screen combinations as AOG+KS, AOG+KH, and AO+KH. Individual ROC curves of 4 observers and 3 film-screen combinations, and pooled ROC curves were analysed. No definite difference of observer performance between 4 observer, and there was superior ROC curve in AO+KH combination than others. The results demonstrate that ROC analysis was useful for evaluating observer performance in detecting task of diagnostic imaging technique.