Cause of satisfaction of search effects in contrast studies of the abdomen

Rationale and Objectives. Extraintestinal abnormalities visible without contrast material on abdominal radiographs are reported less frequently when contrast examinations are performed. Gaze dwell time was used to determine whether this difference is due to failure by observers to scan plain-film regions of contrast studies or discounting of plain-film abnormalities that were actually scanned. Methods. Patients were included whose contrast studies had elicited the largest reductions in positive responses compared with their plain-film studies in a previous detection experiment. Gaze of 10 radiologists was studied. Results. Significantly less time was spent gazing at non-contrast regions of contrast examinations than at the corresponding regions of radiographs. Errors with radiographs were based primarily on failures of recognition and decision making, whereas errors with contrast studies were based primarily on faulty scanning. Conclusion. Satisfaction of search errors on contrast examinations are caused by reduction in scanning of noncontrast regions.