PRECLINICAL ROC STUDIES OF DIGITAL STEREOMAMMOGRAPHY

This paper reports the diagnostic performance of observers in detectin g abnormalities in computer-generated mammogram-like images, A mathema tical model of the human breast is defined in which breast tissues are simulated by spheres of different sizes and densities, Images are gen erated by casting rays from a specified source, through the model, and onto an image plane, Observer performance when using two viewing moda lities (stereo versus mono) is compared, In the stereo viewing mode, i mages are presented to the observer (wearing liquid-crystal display gl asses), such that the left eye sees the left image only and the right eye sees the right image only. In this way, the images can be fused by the observer to obtain a sense of depth, In the mono viewing mode, id entical images are presented to the left and right eyes so that no bin ocular disparities will be produced by the images, Observer response d ata are evaluated using receiver operating characteristic (ROC) analys is to characterize any difference in detectability of abnormalities (i n either the density or the arrangement of simulated tissue densities) using the two viewing modes. Our experimental results indicate the cl ear superiority of stereo viewing for detection of arrangement abnorma lities, For detection of density abnormalities, the performance of the two viewing modes is similar, These preliminary results suggest that stereomammography may permit easier detection of certain tissue abnorm alities, perhaps providing a route to earlier tumor detection in cases of breast cancer.