Venjakob Antje C, Marnitz Tim, Phillips Peter, Mello-Thoms Claudia R
Technische Universität Berlin, Berlin, Germany
Charité Universitätsmedizin Berlin, Berlin, Germany.
Hum Factors. 2016 May;58(3):441-51. doi: 10.1177/0018720816630450. Epub 2016 Mar 2.
The aim of this study was to explore reader gaze, performance, and preference during interpretation of cranial computed tomography (cCT) in stack mode at two different sizes.
Digital display of medical images allows for the manipulation of many imaging factors, like image size, by the radiologists, yet it is often not known what display parameters better suit human perception.
Twenty-one radiologists provided informed consent to be eye tracked while reading 20 cCT cases. Half of these cases were presented at a size of 14 × 14 cm (512 × 512 pixels), half at 28 × 28 cm (1,024 × 1,024 pixels). Visual search, performance, and preference for the two image sizes were assessed.
When reading small images, significantly fewer, but longer, fixations were observed, and these fixations covered significantly more slices. Time to first fixation of true positive findings was faster in small images, but dwell time on true findings was longer. Readers made more false positive decisions in small images, but no overall difference in either jackknife alternative free-response receiver operating characteristic or reading time was found.
Overall performance is not affected by image size. However, small-stack-mode cCT images may better support the use of motion perception and acquiring an overview, whereas large-stack-mode cCT images seem better suited for detailed analyses.
Subjective and eye-tracking data suggest that image size influences how images are searched and that different search strategies might be beneficial under different circumstances.
本研究旨在探讨在两种不同尺寸的叠加模式下解读头颅计算机断层扫描（cCT）时读者的注视情况、表现和偏好。
医学图像的数字显示使放射科医生能够操控许多成像因素，如图像大小，但通常并不清楚哪些显示参数更适合人类感知。
21名放射科医生在阅读20例cCT病例时提供知情同意以进行眼动追踪。其中一半病例以14×14厘米（512×512像素）的尺寸呈现，另一半以28×28厘米（1024×1024像素）的尺寸呈现。评估了对这两种图像尺寸的视觉搜索、表现和偏好。
阅读小图像时，观察到的注视点明显更少但持续时间更长，且这些注视点覆盖的切片明显更多。小图像中真阳性发现的首次注视时间更快，但对真发现的停留时间更长。读者在小图像中做出的假阳性判断更多，但在留一法替代自由反应接受者操作特征或阅读时间方面均未发现总体差异。
总体表现不受图像大小的影响。然而，小叠加模式的cCT图像可能更有利于运动感知的运用和获取概览，而大叠加模式的cCT图像似乎更适合进行详细分析。
主观和眼动追踪数据表明，图像大小会影响图像的搜索方式，并且不同的搜索策略在不同情况下可能是有益的。
