DETECTABILITY OF SIMULATED LOW-CONTRAST OBJECTS : COMPARISON OF CONTACT, MAGNIFICATION AND STEREO RADIOGRAPHS

Abstract

We investigated the delectability of simulated low contrast radiographic small objects imaged by contact, magnification and stereo techniques. Signal patterns were simulated by 2 mm plastic beads with and without structured noise. The delectability of simulated patterns was quantified in terms of the results of observer performance experiments by using the ROC method. Signal detection for magnification and stereo radiographs was greater than that for contact radiographs. That was especially improved by 2X magnification technique even if objects have structured noise in the background. The improvement in detectability by 2X magnification radiographs can be explained from the viewpoint of signal-to-noise ratio included the observer's internal noise.