探討低事件率對醫學圖像視覺搜索漏報的影響,用SMI250眼動儀記錄放射科專家與新手檢測胸部X光片的過程。結果發現:(1)專家和新手在低事件率(10%)下的漏報率多于高事件率(50%),但專家在高低事件率的漏報率的差值小于新手。(2)專家和新手在低事件率下的注視次數少于高事件率,眼跳幅度、掃描錯誤比例大于高事件率。結論認為:專家與新手進行醫學圖像視覺搜索時出現低事件率效應,低事件率效應主要是由于掃描錯誤引起的。

To measure the effect of abnormality-prevalence on novices and experienced radiologists ′ performance during pulmonary nodular lesion detection on a chest radiograph,SMI250 eye tracker was used to record participants ′eye movements.We asked experts and novices to detect chest X-ray in different target prevalence(50% or10%).The results showed that:1) the miss(false-negative) rate of experts and novices in low prevalence(10%) was significantly higher than that of high prevalence(50%),but the miss rate difference of experts in high and low prevalence was less than that of novices.2) Experts and novices spent less fixation counts but more fixation duration average in low prevalence.In addition,the average saccade amplitude and the scanning error in low prevalence were greater than that in high prevalence.These findings suggested that scanning errors were the main reason for the more miss errors in low prevalence than those in high prevalence.