Does Expectation of Abnormality Affect the Search Pattern of Radiologists When Looking for Pulmonary Nodules?

Abstract

This experiment investigated whether there might be an effect on the visual search strategy of radiologists during image interpretation of the same adult chest radiographs when given different clinical information. Each of 17 experienced radiologists was asked to interpret a set of 57 (10 abnormal) posteroanterior chest images to identify the presence of pulmonary lesions using differing clinical information (leading to unknown, low and high expectations of prevalence). Eye position metrics (search time, dwell time and time to first fixation) were compared for normal and abnormal images, as well as between conditions. For all images, there was a significantly longer search time at high prevalence expectation compared to low prevalence expectation (W = 75.19, P = <0.0001). Mann-Whitney analysis of the abnormal images demonstrated that the dwell time on correctly identified lesions was significantly shorter at low prevalence expectation compared to both unknown (U = 364.5, P = 0.02) and high prevalence expectation (U = 397.0, P = 0.0002). Visual search patterns of radiologists appear to be affected by changing a priori information where such information fosters an expectation of abnormality.

Diagnosing Crime and Diagnosing Disease‐II: Visual Pattern Perception and Diagnostic Accuracy

“…When they were expecting a high prevalence of abnormality, such as a past history of malignancy from referral information, they showed a reduced ability to recognize normal images, tending to mislabel normal appearances. An expectation of abnormality may thus lead to a false‐positive identification . Eye movement tracking experiments lend support to this presumption .…”

“…An expectation of abnormality may thus lead to a false‐positive identification . Eye movement tracking experiments lend support to this presumption . When not expecting to find an abnormality, the duration of visual search is shorter.…”

“… both have been studied at a perceptual level, including eye tracking both have been studied using signal detection theory both have been studied in terms of the relation between confidence and accuracy . …”

“…This finding parallels Littlefair's experimental eye tracking data. Such “satisfaction of search” is another instance of how prior information misleads .…”

“…This alters the sequence of test reading routines. By far, the typical test interpretation sequence is to refer to available clinical referral (or history), then read the test, and lastly interpret the findings to render a diagnostic impression to the referral source . Changing this time‐honored sequence can be a key to reducing errors in test interpretations.…”