Ergun D L, Mistretta C A, Brown D E, Bystrianyk R T, Sze W K, Kelcz F, Naidich D P
Philips Medical Systems North America, Shelton, CT 06484.
Radiology. 1990 Jan;174(1):243-9. doi: 10.1148/radiology.174.1.2294555.
Recent reports have emphasized the potential for dual-energy computed radiographic applications. An improved method for single-exposure material-selective imaging with a photostimulable phosphor computed radiography system was investigated. The essential elements of the technique are (a) prefiltration with gadolinium, which divides the incident broad-beam x-ray spectrum into low-energy and high-energy peaks; (b) a cassette consisting of four photostimulable phosphor plates that record images of increasing mean energies, with a computed energy separation of 23 keV from the front to the rear plate; (c) spatially dependent scatter and beam-hardening corrections; and (d) a noise-reduction algorithm based on noise correlations between bone-selective and soft-tissue-selective dual-energy images. These elements result in improved material cancellation and signal-to-noise ratio throughout the image.
近期报告强调了双能计算机射线照相应用的潜力。研究了一种利用光激励荧光体计算机射线照相系统进行单曝光材料选择性成像的改进方法。该技术的基本要素包括：(a) 用钆进行预过滤，将入射的宽束X射线光谱分为低能峰和高能峰；(b) 一个暗盒，由四个光激励荧光体板组成，记录平均能量不断增加的图像，从前板到后板计算能量间隔为23 keV；(c) 空间相关散射和束硬化校正；以及(d) 一种基于骨选择性和软组织选择性双能图像之间噪声相关性的降噪算法。这些要素可在整个图像中改善材料消除效果并提高信噪比。
