Lago Miguel A, Sechopoulos Ioannis, Bochud François O, Eckstein Miguel P
University of California, Institute for Collaborative Biotechnologies, Department of Psychological and Brain Sciences, Santa Barbara, California, United States.
Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen, The Netherlands.
J Med Imaging (Bellingham). 2020 Mar;7(2):022411. doi: 10.1117/1.JMI.7.2.022411. Epub 2020 Feb 8.
: With three-dimensional (3-D) images displayed as stacks of 2-D images, radiologists rely more heavily on vision away from their fixation point to visually process information, guide eye movements, and detect abnormalities. Thus the ability to detect targets away from the fixation point, commonly characterized as the useful field of view (UFOV), becomes critical for these 3-D imaging modalities. We investigate how the UFOV, defined as the eccentricity, in which detection performance degrades to a given probability, varies across imaging modalities and targets. : We measure the detectability of different targets at various distances from gaze locations for single slices of liver computed tomography (CT), 2-D digital mammograms (DM), and single slices of digital breast tomosynthesis (DBT) cases. Observers with varying expertise were instructed to maintain their gaze at a point while a short display of the image was flashed and an eye tracker verified observer's steady fixation. Display times were 200 and 1000 ms for CT images and 500 ms for DM and DBT images. : We find variations in the UFOV from 9 to 12 deg for liver CT to as small as 2.5 to 5 deg for calcification clusters in breast images (DM and DBT). We compare our results to those reported in the literature for lung nodules and discuss the differences across methods used to measure the UFOV, their dependence on case selection/task difficulty, viewing conditions, and observer expertise. We propose a complementary measure defined in terms of performance degradation relative to the peak foveal performance (relative-UFOV) to circumvent UFOV's variations with case selection/task difficulty. : Our results highlight the variations in the UFOV across imaging modalities, target types, observer expertise, and measurement methods and suggest an additional relative-UFOV measure to more thoroughly characterize the detection performance away from point of fixation.
由于三维（3-D）图像以二维图像堆栈的形式显示，放射科医生在视觉处理信息、引导眼球运动和检测异常时，对远离其注视点的视觉依赖程度更高。因此，检测远离注视点目标的能力，通常被称为有用视野（UFOV），对于这些三维成像模式至关重要。我们研究了定义为检测性能下降到给定概率时的偏心率的UFOV如何随成像模式和目标而变化。我们测量了肝脏计算机断层扫描（CT）单切片、二维数字乳腺X线摄影（DM）和数字乳腺断层合成（DBT）单切片病例中不同目标在距注视位置不同距离处的可检测性。指导不同专业水平的观察者在图像短暂闪烁时将目光保持在一点上，同时眼动仪验证观察者的稳定注视。CT图像的显示时间为200和1000毫秒，DM和DBT图像的显示时间为500毫秒。我们发现肝脏CT的UFOV在9至12度之间变化，而乳腺图像（DM和DBT）中钙化簇的UFOV小至2.5至5度。我们将我们的结果与文献中报道的肺结节结果进行比较，并讨论用于测量UFOV的不同方法之间的差异、它们对病例选择/任务难度、观察条件和观察者专业知识的依赖性。我们提出了一种基于相对于中央凹峰值性能的性能下降定义的补充测量方法（相对UFOV），以规避UFOV随病例选择/任务难度的变化。我们的结果突出了UFOV在成像模式、目标类型、观察者专业知识和测量方法之间的差异，并提出了一种额外的相对UFOV测量方法，以更全面地表征远离注视点的检测性能。
