Visual Search Characteristics in Mammography: Malignant vs Benign Breast Masses

摘要

Mammography screening is the most widely utilized tool to screen for breast cancer. Radiologists read a mammogram using a two-pass strategy where the first pass is guided by salient features of the image (the so-called 'pop-out' elements), and the second pass is a systematic search. It is assumed that most breast masses that are reported by the radiologist are in fact detected during the first pass of this search strategy, and that the second pass is useful for the detection of microcalcification clusters. Furthermore, experiments in other visual domains have shown that observers are attracted faster to incongruous elements in a display than to normal (i.e., more expected) elements. In this sense, it can be argued that benign findings constitute more expected findings, because they encompass a large percentage of all abnormalities found on a mammogram. In this experiment we sought to determine whether the search for malignant masses was indeed faster than the search for benign masses. We also aimed to determine whether the observers' overall visual search behavior was different between benign and malignant cases, not only in terms of how long it took the observers to hit the location of the lesion, but also how long the observers took analyzing the case, how different the distribution of false positive responses were between the two types of cases, etc.