Samei E, Flynn M J, Eyler W R
Department of Diagnostic Radiology, Henry Ford Health System, Detroit, MI 48202, USA.
Radiology. 1999 Dec;213(3):727-34. doi: 10.1148/radiology.213.3.r99dc19727.
To assess the relative influence of quantum mottle and structured lung patterns (anatomic noise) on the detection of subtle lung nodules on chest radiographs.
Sixty 8 x 8-cm lung pattern images were extracted from digital chest radiographs in healthy individuals. Sixty quantum mottle images of the same size and quantum noise level were extracted from uniformly exposed digital radiographs. Simulated nodules with various peak contrast-diameter products (CD) that emulated subtle tissue-equivalent lung nodules were numerically superimposed at the center on three-fourths of the images. Printouts were independently viewed and scored by five experienced radiologists. The area under the receiver operating characteristic curve (Az) was estimated as a measure of the detectability of the nodules.
At a fixed observer performance level (e.g., Az = 0.8), much smaller and lower-contrast nodules were detected on quantum mottle images (1-mm diameter, CD = 0.01 mm), compared with those on anatomic images (4.5-mm diameter, CD = 0.20 mm). The findings generally agreed with the signal-to-noise ratio calculations based on statistical observer models.
The detection of subtle lung nodules on chest radiographs is limited by anatomic noise.
评估量子斑点和肺部结构影像（解剖噪声）对胸部X光片上微小肺结节检测的相对影响。
从健康个体的数字化胸部X光片中提取60张8×8厘米的肺部影像。从均匀曝光的数字化X光片中提取60张相同尺寸和量子噪声水平的量子斑点影像。将模拟具有各种峰值对比度-直径乘积（CD）的结节，模拟微小组织等效性肺结节，以数字方式叠加在四分之三图像的中心。由五名经验丰富的放射科医生独立查看并对打印件进行评分。估计接收器操作特性曲线（Az）下的面积作为结节可检测性的度量。
在固定的观察者表现水平（例如，Az = 0.8）下，与解剖影像（直径4.5毫米，CD = 0.20毫米）相比，在量子斑点影像上检测到的结节要小得多且对比度更低（直径1毫米，CD = 0.01毫米）。这些发现总体上与基于统计观察者模型的信噪比计算结果一致。
胸部X光片上微小肺结节的检测受解剖噪声限制。
