Department of Radiology, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, 20133, Milan, Italy.
Department of Radiology, Ospedale San Bassiano, Via Dei Lotti 40, 36061, Bassano del Grappa (VI), Italy.
Radiol Med. 2018 Aug;123(8):586-592. doi: 10.1007/s11547-018-0891-6. Epub 2018 Apr 18.
To evaluate the effects of display pixel pitch and maximum luminance on intra- and inter-observer reproducibility and observer performance when evaluating chest lesions and bone fractures.
This was a multi-institutional study for a retrospective interpretation of selected digital radiography images. Overall, 82 images were selected by senior radiologists, including 50 cases of chest lesions and 32 cases of bone fractures. These images were displayed at two pixel pitches (0.212 and 0.165 mm size pixels) and two maximum luminance values (250 and 500 cd/m) and reviewed twice by senior and junior radiologists. All the observers had to indicate the likelihood of the presence of the lesions and to rate the relative confidence of their assessment. Cohen Kappa statistic was computed to estimate the reproducibility in correctly identifying lesions; for multi-reader-multi-case (MRMC) analysis, weighted Jackknife Alternative Free-response Receiver Operating Characteristic (wJAFROC) statistical tools was applied.
The intra-radiologist and inter-observer reproducibility values were the highest for the 0.165 mm size pixel at 500 cd/m display, for both chest lesions and bone fractures evaluations. As regards chest lesions, observer performances were significantly greater with 0.165 mm size pixel display at 500 cd/m than with lower maximum luminance and/or larger pixel pitch displays. Concerning bone fractures, the performance obtained with 0.212 mm size pixel display at 250 cd/m was statistically lower than that obtained with 0.165 mm sixe pixel display at 500 cd/m.
Our results indicate that an increased maximum luminance level and a decreased pixel pitch of medical-grade display improve the accuracy of detecting both chest lesions and bone fractures.
评估显示像素间距和最大亮度对评估胸部病变和骨折时的观察者内和观察者间可重复性和观察者性能的影响。
这是一项多机构研究，用于回顾性解释选定的数字射线照相图像。总共由资深放射科医生选择了 82 张图像，包括 50 例胸部病变和 32 例骨折。这些图像以两种像素间距（0.212 和 0.165 毫米大小像素）和两种最大亮度值（250 和 500 cd/m）显示，并由资深和初级放射科医生两次审查。所有观察者都必须指出病变存在的可能性，并对其评估的相对置信度进行评分。使用 Cohen Kappa 统计量来估计正确识别病变的可重复性；对于多读者多病例（MRMC）分析，应用加权 Jackknife 替代自由响应接收器操作特征（wJAFROC）统计工具。
在最大亮度为 500 cd/m 时，0.165 毫米大小像素的观察者内和观察者间可重复性值对于胸部病变和骨折评估都是最高的。就胸部病变而言，与较低的最大亮度和/或较大的像素间距显示相比，观察者在 0.165 毫米大小像素显示在 500 cd/m 时的性能显著更高。关于骨折，在最大亮度为 250 cd/m 时，0.212 毫米大小像素的显示性能明显低于在最大亮度为 500 cd/m 时 0.165 毫米大小像素的显示性能。
我们的结果表明，提高医疗级显示器的最大亮度水平和降低像素间距可以提高检测胸部病变和骨折的准确性。
