Nature of expertise in searching mammograms for breast masses

Abstract

The authors investigated how training and experience affect the performance of observers searching mammograms for breast masses. Eye positions of mammographers, mammography technologists, mammography residents, and laypersons were compared to scan paths generated by a simulated scanner as each searched nine two-view digital mammogram pairs for breast masses. Analysis of time-to-hit data revealed that mammographers and mammography technologists with the most extensive training and experience had the fastest search times in the detection and confirmation of a breast mass on two views. Scanning patterns of less-experienced mammography residents were less efficient due to wider dispersion of visual attention between potential breast masses and perturbations in breast parenchyma. Because laypersons lacked both training and experience in mammography, bright blobs in the breast image were considered to be intuitively valid target candidates and these features distracted the search by capturing visual attention. Experience reading normal and abnormal mammograms plays a critical role in training radiologists. Experience combined with training provides the basis for generating efficient visual search strategies and developing distinctive conceptual criteria for perceptual differentiation and interpretation of true breast masses from image artifacts and structured noise that mimics breast abnormalities.