Detection of simulated microcalcifications in a phantom with digital mammography: effect of pixel size.
Detection of simulated microcalcifications in a phantom with digital mammography: effect of pixel size.
复制标题
使用数字乳房X线照相术检测体模中的模拟微钙化：像素大小的影响。
DOI：
10.1148/radiol.2441060977
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发表时间：
2007
期刊：
影响因子：
19.7
通讯作者：
D'Orsi,CarlJ
中科院分区：
文献类型：
--
作者：
Suryanarayanan,Sankararaman;Karellas,Andrew;Vedantham,Srinivasan;Sechopoulos,Ioannis;D'Orsi,CarlJ
Purpose:To evaluate the effect of pixel size on the detection of simulated microcalcifications in a phantom with digital mammography.Materials and Methods:A high-spatial-resolution prototype imager that yields variable pixel size (39 and 78 μm) and a clinical full-field digital mammography (FFDM) system that yields a 100-μm pixel size were used. Radiographic images of a contrast-detail (CD) phantom were obtained to perform four-alternative forced-choice observer experiments. Polymethylmethacrylate was added to obtain phantom thicknesses of 45 and 58 mm, which are typical breast thicknesses encountered in mammography. Phantom images were acquired with both systems under nearly identical exposure conditions by using an antiscatter grid. Twelve images were acquired for each phantom thickness and pixel size (for a total of 72 images), and six observers participated in this study. Observer responses were used to compute the fraction of correctly detected disks. A signal detection model was used to fit the recorded data from which CD characteristics were obtained. Repeated-measures analyses with mixed-effects linear models were performed for each of the six observers. All statistical tests were two sided and unadjusted for multiple comparisons. APvalue of .05 or less was considered to indicate a significant difference.Results:Statistical analysis revealed significantly better CD characteristics with 39- and 78-μm pixel sizes compared with 100-μm pixel size for all disk diameters and phantom thicknesses (P< .001). Increase in phantom thickness degraded CD characteristics regardless of pixel size (P< .001).Conclusion:On the basis of the conditions of this study, reducing pixel size below 100 μm with low imaging system noise enhances the visual perception of small objects that correspond to typical microcalcifications.© RSNA, 2007
