Radiation dose reduction without degradation of low-contrast detectability at abdominal multisection CT with a low-tube voltage technique: Phantom study
Radiation dose reduction without degradation of low-contrast detectability at abdominal multisection CT with a low-tube voltage technique: Phantom study
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DOI：
10.1148/radiol.2373041643
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发表时间：
2005-12-01
期刊：
影响因子：
19.7
通讯作者：
Yamashita, Y
中科院分区：
文献类型：
--
作者：
Funama, Y;Awai, K;Yamashita, Y
目得：通过使用低管电压（90 W）技术降低腹部计算机断层扫描（CT）的辐射剂量，而不降低低对比度可检测性。材料和方法：机构审查委员会批准放射科医师参与观察员性能测试，并获得所有参与放射科医师的知情同意，用16排CT扫描仪在120 W和90 W下扫描用于测量辐射剂量的体模和包含低对比度物体的体模。为了确定90 W和120 W的辐射剂量，管电流-时间乘积设置为100-560 mAs，并测量体模中心和外围的剂量。为了评估低对比度的可接受性，我们在120 W时使用300 mAs设置，在90 W时使用250-560 mAs设置。5名观察员参与了受试者操作特性分析。计算每个观察者的受试者工作特征曲线下面积（A（z））值。记录每种扫描技术获得的A值，并通过Dunnet方法检查差异的显著性。结果：在120 W和300 mAs时，平均A值为0.951。在90 W和450-560 mAs下，A值为0.927-0.973，这些值与在120 W和300 mAs下获得的值之间的差异不显著（P = 0.937 - 0.952）。在120 W和300 mAs条件下，向体模中心输送的辐射剂量值为100%。在90 W的相对剂量范围从65%在450 mAs到79%在560 mAs.CONCLUSION：从120 W到90 W的减少导致多达35%的辐射剂量减少，而不牺牲低对比度的可检测性，在CT。(c)RSNA，2005年。
PURPOSE: To reduce radiation dose from abdominal computed tomography (CT) without degradation of low-contrast detectability by using a technique with low tube voltage (90 W).MATERIALS AND METHODS: The institutional review board approved the participation of the radiologists in the observer performance test, and informed consent was obtained from all participating radiologists, A phantom for measurement of the radiation dose and a phantom containing low-contrast objects were scanned with a 16-detector row CT scanner at 120 W and 90 W. For determination of the radiation dose at both 90 W and 120 W, the tube current-time product settings were 100-560 mAs, and the doses at the center and periphery of the phantom were measured. To assess low-contrast delectability, we used a 300-mAs setting at 120 W and 250-560-mAs settings at 90 W. Five observers participated in the receiver operating characteristic analysis. Area under the receiver operating characteristic curve (A(z)) values were calculated in each observer. A, values obtained with each of the scanning techniques were recorded, and differences were examined for significance by using the Dunnet method.RESULTS: The mean A, value was 0.951 at 120 W and 300 mAs. A, values were 0.927-0.973 at 90 W and 450-560 mAs, and the differences between those values and values obtained at 120 W and 300 mAs were not significant (P = .937-.952). A value of 100% was assigned to the radiation dose delivered to the center of the phantom at 120 W and 300 mAs. The relative dose delivered at 90 W ranged from 65% at 450 mAs to 79% at 560 mAs.CONCLUSION: A reduction from 120 W to 90 W led to as much as a 35% reduction in the radiation dose, without sacrifice of low-contrast detectability, at CT. (c) RSNA, 2005.