Duke P R, Hanson J A
Med Phys. 1984 Sep-Oct;11(5):624-32. doi: 10.1118/1.595557.
The use of x-ray tubes as radiation sources for Compton scatter densitometry (CSD) is evaluated theoretically. Bias correction factors (bcf's) which correct for differential attenuation due to Compton shift and polychromaticity, and differential scattering cross section due to polychromaticity, are defined to facilitate comparison of monochromatic and x-ray tube CSD devices. Computer modeling indicates that a 100-kVp x-ray tube spectrum hardened with 0.64 mm of Pb filtration yields bcf's 0.008 to 0.34% higher than a 70-keV monochromatic source for various samples of nylon, and human muscle and bone. This difference is insignificant because multiple scatter errors are typically 1000% higher than errors corrected by bcf's. The high equivalent activities of x-ray tubes (10 to 80 TBq) and their small focal spots (1.0 to 2.0 mm) allow the long-standing CSD problems of marginal statistical precision, long counting times, and low spatial resolution to be overcome.
对将X射线管用作康普顿散射密度计（CSD）辐射源的情况进行了理论评估。定义了偏差校正因子（bcf），用于校正由于康普顿位移和多色性导致的差异衰减，以及由于多色性导致的差异散射截面，以方便比较单色和X射线管CSD设备。计算机模拟表明，对于尼龙、人体肌肉和骨骼的各种样本，用0.64毫米铅过滤使能谱硬化的100 kVp X射线管产生的bcf比70 keV单色源高0.008%至0.34%。这种差异并不显著，因为多重散射误差通常比bcf校正的误差高1000%。X射线管的等效活度高（10至80 TBq）且焦点小（1.0至2.0毫米），使得长期存在的CSD在统计精度、计数时间长和空间分辨率低等问题得以克服。
