Quantitative optical densitometry with scanning-laser film digitizers.
Quantitative optical densitometry with scanning-laser film digitizers.
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使用扫描激光胶片数字化仪进行定量光密度测定。
DOI：
10.1118/1.598664
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发表时间：
1999
期刊：
影响因子：
3.8
通讯作者：
J. Williamson
中科院分区：
文献类型：
--
作者：
J. Dempsey;D. Low;A. Kirov;J. Williamson
提出了一种消除市售透射扫描激光胶片数字化仪中固有的两种伪影的新工艺。第一种伪影导致不可再现的干涉图样波动高达 7%。第二种导致透射光在 OD 快速变化的区域中从低光密度 (OD) 传播到高光密度 (OD)，产生高达 50% 的误差。这些 OD 伪影导致低 OD 区域（第一类型）的薄膜精度损失，以及高 OD 梯度附近的高 OD 区域（第二类型）的薄膜精度损失。通过均匀暴露于 6 MV 光子束和高剂量率 192Ir 近距离放射治疗源产生的测试放射变色胶片以及测试放射照相胶片用于表征市售扫描激光胶片数字化仪的伪影。通过在掩模漫射磨砂玻璃扫描床上对胶片进行数字化，消除了干涉图案伪影。通过使用测量的数字转换器线扩展函数对传输曲线进行离散快速傅立叶变换 (DFFT) 去卷积，消除了光传输伪影。在 DFFT 反卷积后获得精确的 OD 分布需要事先去除干扰图案伪影并应用低通维纳噪声滤波器。光传输伪影对于需要测量高梯度 OD 分布的应用尤其重要，例如近距离放射治疗或保形光子束薄膜剂量测定和二维电泳凝胶的定量。代表这些应用的 OD 分布中出现高达 15%-35% 的误差。本研究中开发的数据收集和校正过程成功地消除了这些伪影。
A new process for eliminating two types of artifacts inherent in commercially available transmission scanning-laser film digitizers is presented. The first kind of artifact results in nonreproducible interference-pattern fluctuations as large as 7%. The second kind results in spreading of transmitted light from low-to-high optical density (OD) in regions with rapidly varying ODs, producing errors as large as 50%. These OD artifacts cause the loss of precision for films with low-OD regions (first type) and the loss of accuracy for films with regions of high-OD near high-OD gradients (second type). Test radiochromic films, produced by uniform exposure to a 6 MV photon beam and a high dose rate 192Ir brachytherapy source, along with test radiographic films were used to characterize the artifacts of a commercially available scanning-laser film digitizer. The interference-pattern artifact was eliminated by digitizing the films on a masked diffusing ground-glass scanning bed. The light-transmission artifact was eliminated through discrete-fast-Fourier-transform (DFFT) deconvolution of transmission profiles with measured digitizer line-spread functions. Obtaining precise OD distributions after the DFFT deconvolution required prior removal of the interference-pattern artifact and application of a low-pass Wiener noise filter. Light-transmission artifacts are particularly significant for applications requiring measurement of high-gradient OD distributions, such as brachytherapy or conformal photon-beam film dosimetry and quantitation of two-dimensional electrophoresis gels. Errors as large as 15%-35% occur in OD distributions representative of these applications. The data collection and correction process developed in this study successfully removes these artifacts.
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用于二维凝胶定量分析的 QUEST 系统。
DOI：
--
发表时间：
1989
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Garrels,JI
通讯作者：
Garrels,JI
用于 125I 种子的高灵敏度 GafChromic 薄膜剂量测定。
影响因子：
3.8
作者：
Chiu-Tsao,ST;delaZerda,A;Lin,J;Kim,JH
通讯作者：
Kim,JH
影响因子：
3.8
作者：
MUENCH, PJ;MEIGOONI, AS;MCLAUGHLIN, WL
通讯作者：
MCLAUGHLIN, WL
兆伏光子束的薄膜剂量测定：等密度到等剂量曲线转换的实用方法。
影响因子：
3.8
作者：
Williamson,JF;Khan,FM;Sharma,SC
通讯作者：
Sharma,SC