Shaw C C, Wang T, King J L, Breitenstein D S, Chang T S, Harris K M, Baratz A B, Ganott M A, Reginella R, Sumkin J H, Gur D
Department of Radiology, University of Pittsburgh, PA 15261-0001, USA.
Acad Radiol. 1998 Mar;5(3):173-80. doi: 10.1016/s1076-6332(98)80281-x.
The authors compare a 43-micron computed radiographic system with a mammographic screen-film system for detection of simulated microcalcifications in an observer-performance study.
The task of detecting microcalcifications was simulated by imaging aluminum wire segments (200-500 microns in length; 100, 125, or 150 microns in diameter) that overlapped with tissue background structures produced by beef brisket. A total of 288 such simulations were generated and examined with both computed radiography and conventional screen-film mammography techniques. Computed radiography was performed with high-resolution plates, a 43-micron image reader, and a 43-micron laser film printer. Computed radiographic images were printed with simple contrast enhancement and compared with screen-film images in a receiver operating characteristic study in which experienced readers detected and scored the simulated microcalcifications. Observer performance was quantitated and compared by computing the area under the receiver operating characteristic curve.
Although the resolution of the computed radiography system was better than that of commercial systems, it fell short of that of screen-film systems. For the 100-micron microcalcifications, the difference in the average area under the curve was not statistically significant, but it was significant for the larger simulated microcalcifications: the average area under the curve was 0.58 for computed radiography versus 0.76 for screen-film imaging for the 125-micron microcalcifications and 0.83 versus 1.00, respectively, for the 150-micron microcalcifications.
Observer performance in the detection of small simulated microcalcifications (100-150 microns in diameter) is better with screen-film images than with high-resolution computed radiographic images.
在一项观察者性能研究中，作者将43微米的计算机X线摄影系统与乳腺X线屏-片系统用于检测模拟微钙化灶进行比较。
通过对与牛胸肉产生的组织背景结构重叠的铝线段（长度200 - 500微米；直径100、125或150微米）进行成像来模拟微钙化灶的检测任务。共生成288个这样的模拟影像，并采用计算机X线摄影和传统屏-片乳腺摄影技术进行检查。计算机X线摄影使用高分辨率平板、43微米的图像读取器和43微米的激光胶片打印机。计算机X线摄影图像通过简单的对比度增强进行打印，并在接受操作特征研究中与屏-片图像进行比较，由经验丰富的阅片者对模拟微钙化灶进行检测和评分。通过计算接受操作特征曲线下的面积来定量和比较观察者的性能。
尽管计算机X线摄影系统的分辨率优于商业系统，但仍低于屏-片系统。对于100微米的微钙化灶，曲线下平均面积的差异无统计学意义，但对于较大的模拟微钙化灶则有显著差异：对于125微米的微钙化灶，计算机X线摄影的曲线下平均面积为0.58，而屏-片成像为0.76；对于150微米的微钙化灶，分别为0.83和1.00。
在检测小的模拟微钙化灶（直径100 - 150微米）时，观察者使用屏-片图像的性能优于高分辨率计算机X线摄影图像。
