Optimized radiographic spectra for small animal digital subtraction angiography
Optimized radiographic spectra for small animal digital subtraction angiography
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DOI：
10.1118/1.2356646
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发表时间：
2006-11-01
期刊：
影响因子：
3.8
通讯作者：
Johnson, G. Allan
中科院分区：
文献类型：
--
作者：
De Lin, Ming;Samei, Ehsan;Johnson, G. Allan
在基础研究中越来越多地使用小动物，激发了人们对新成像方法的兴趣。数字减影血管造影术（DSA）为小动物的功能成像提供了一种特别有吸引力的方法。本研究检查了最佳X射线、钼（Mo）或钨（W）靶源，以及在对比度和信噪比平方（SdNR（2））方面生成最高质量小动物功能减影血管造影片的技术。考虑了两个限制条件-相对于剂量的标准化和相对于管负载的标准化。图像对比度和SdNR 2使用建立的X射线模型进行模拟。在W和Mo源的两个代表性管电位下拍摄活体大鼠的DSA图像。结果表明，对于小动物DSA，钼源提供了更好的对比度。然而，对于数字检波器，SdNR（2）是更相关的品质因数。在kVps > 60下工作的W源实现了较高的SdNR（2）。在90 kVp以上的电压下获得最高的SdNR（2）。然而，在更高电位下的操作导致显著更大的剂量和管负载以及减少的对比量化。在性能平稳期开始时的管电位（约70 kVp）处可以实现合理的折衷，此时SdNR（2）中的相对增益最大。(c)2006年美国医学物理学家协会。
The increasing use of small animals in basic research has spurred interest in new imaging methodologies. Digital subtraction angiography (DSA) offers a particularly appealing approach to functional imaging in the small animal. This study examines the optimal x-ray, molybdenum (Mo) or tungsten (W) target sources, and technique to produce the highest quality small animal functional subtraction angiograms in terms of contrast and signal-difference-to-noise ratio squared (SdNR(2)). Two limiting conditions were considered-normalization with respect to dose and normalization against tube loading. Image contrast and SdNR2 were simulated using an established x-ray model. DSA images of live rats were taken at two representative tube potentials for the W and Mo sources. Results show that for small animal DSA, the Mo source provides better contrast. However, with digital detectors, SdNR(2) is the more relevant figure of merit. The W source operated at kVps > 60 achieved a higher SdNR(2). The highest SdNR(2) was obtained at voltages above 90 kVp. However, operation at the higher potential results in significantly greater dose and tube load and reduced contrast quantization. A reasonable tradeoff can be achieved at tube potentials at the beginning of the performance plateau, around 70 kVp, where the relative gain in SdNR(2) is the greatest. (c) 2006 American Association of Physicists in Medicine.