Perception of simulated lung lesions.

Two series of test radiographs were produced, each containing a single nodular lesion. Each series was identical except that the lesions were spatially shifted with respect to adjacent structures, resulting in matched pairs of chest radiographs simulating a stereoscopic examination. Observation of each set singly and in pairs (non-stereoscopically) demonstrated a marked improvement in observer performance when the shifted pairs were viewed side-by-side.