CT Image Contrast of High-Z Elements: Phantom Imaging Studies and Clinical Implications
CT Image Contrast of High-Z Elements: Phantom Imaging Studies and Clinical Implications
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DOI：
10.1148/radiol.2015150577
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发表时间：
2016-03-01
期刊：
影响因子：
19.7
通讯作者：
Yeh, Benjamin M.
中科院分区：
文献类型：
--
作者：
FitzGerald, Paul F.;Colborn, Robert E.;Yeh, Benjamin M.
目的：在临床相关的成像条件下，对可能有用的对比剂元素产生的计算机断层扫描(CT)图像对比度进行量化。材料和方法：在水溶液中以化合物的形式表示7种放射性元素的等质量浓度(每毫升溶液中的活性元素克)，包括碘、钡、镓、钽、铟、金和铋。选择的化合物使活性元素控制溶液的X射线衰减。这些溶液在改良的32厘米CT剂量指数模体中以80、100、120和140kVp的CT进行成像。为了模拟更大的机身尺寸，使用了0.2 mm、0.5 mm和1.0 mm厚的铜过滤器。对CT图像对比度进行了测量，并对一些化合物中氯的测量浓度和存在情况进行了校正。结果：在某些试管电位水平上，所测试的每种元素的图像对比度都高于碘。在临床上适用于中等大小和较大成人的管子电位范围内--即100kVp或更高--与碘相比，钡、Gd、Yb和Ta提供了持续增强的图像对比度，分别显示在100kVp时增加39%、56%、34%和24%；在120kvp时增加39%、66%、53%和46%；在不加滤光片的情况下，在140kVp时，Ta的对比度分别增加40%、72%、65%和60%。结论：与等质量浓度的铋和碘相比，Ta在100~140kVp时产生的图像对比度一直很高，提示Ta作为临床CT对比剂具有潜在的应用前景。(C)RSNA，2015年
Purpose: To quantify the computed tomographic (CT) image contrast produced by potentially useful contrast material elements in clinically relevant imaging conditions.Materials and Methods: Equal mass concentrations (grams of active element per milliliter of solution) of seven radiodense elements, including iodine, barium, gadolinium, tantalum, ytterbium, gold, and bismuth, were formulated as compounds in aqueous solutions. The compounds were chosen such that the active element dominated the x-ray attenuation of the solution. The solutions were imaged within a modified 32-cm CT dose index phantom at 80, 100, 120, and 140 kVp at CT. To simulate larger body sizes, 0.2-, 0.5-, and 1.0-mm-thick copper filters were applied. CT image contrast was measured and corrected for measured concentrations and presence of chlorine in some compounds.Results: Each element tested provided higher image contrast than iodine at some tube potential levels. Over the range of tube potentials that are clinically practical for average-sized and larger adults-that is, 100 kVp and higher-barium, gadolinium, ytterbium, and tantalum provided consistently increased image contrast compared with iodine, respectively demonstrating 39%, 56%, 34%, and 24% increases at 100 kVp; 39%, 66%, 53%, and 46% increases at 120 kVp; and 40%, 72%, 65%, and 60% increases at 140 kVp, with no added x-ray filter.Conclusion: The consistently high image contrast produced with 100-140 kVp by tantalum compared with bismuth and iodine at equal mass concentration suggests that tantalum could potentially be favorable for use as a clinical CT contrast agent. (C) RSNA, 2015