Radiologists are reading more cases with more images, especially in CT and MRI and thus working longer hours than
ever before. There have been concerns raised regarding fatigue and whether it impacts diagnostic accuracy. This study
measured the impact of reader visual fatigue by assessing symptoms, visual strain via dark focus of accommodation, and
diagnostic accuracy. Twenty radiologists and 20 radiology residents were given two diagnostic performance tests
searching CT chest sequences for a solitary pulmonary nodule before (rested) and after (tired) a day of clinical reading.
10 cases used free search and navigation, and the other 100 cases used preset scrolling speed and duration. Subjects filled
out the Swedish Occupational Fatigue Inventory (SOFI) and the oculomotor strain subscale of the Simulator Sickness
Questionnaire (SSQ) before each session. Accuracy was measured using ROC techniques. Using Swensson's technique
yields an ROC area = 0.86 rested vs. 0.83 tired, p (one-tailed) = 0.09. Using Swensson's LROC technique yields an area
= 0.73 rested vs. 0.66 tired, p (one-tailed) = 0.09. Using Swensson's Loc Accuracy technique yields an area = 0.77 rested
vs. 0.72 tired, p (one-tailed) = 0.13). Subjective measures of fatigue increased significantly from early to late reading. To
date, the results support our findings with static images and detection of bone fractures. Radiologists at the end of a long
work day experience greater levels of measurable visual fatigue or strain, contributing to a decrease in diagnostic
accuracy. The decrease in accuracy was not as great however as with static images.