Multi-detector row CT: Radiation dose characteristics
Multi-detector row CT: Radiation dose characteristics
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DOI：
10.1148/radiol.2263020205
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发表时间：
2003-03-01
期刊：
影响因子：
19.7
通讯作者：
Thrall, JH
中科院分区：
文献类型：
--
作者：
Hamberg, LM;Rhea, JT;Thrall, JH
目得：为了确定多探测器行计算机断层扫描（CT）的剂量特性，并提供有助于最小化多探测器行CT辐射剂量的列表剂量值和经验法则。（CTDI 100 w）值从三个多探测器行CT扫描仪获得（LightSpeed; GE Medical Systems，密尔沃基，威斯康星州）通过使用标准CT剂量体模进行头部和身体CT模式。CTDI 100 w是X射线管电压（80、100、120、140 kVp）、管电流（范围，50-380 mA）、管旋转时间（0.5-4.0秒）、辐射轮廓宽度（RPW）（5、10、15、20 mm）和采集模式的函数。（螺旋高质量和高速模式以及轴向一段、两段和四段模式）。对CTDI 100 w与各技术因素之间的关系进行统计回归分析。（毫戈瑞）随管电流线性增加：在头部模式下，CTDI 100 w =（0.391 mGy/mA +/- 0.004）X射线管电流（毫安）（r（2）= 0.999）;在体模式下，CTDI 100 w =（0.162 mGy/mA +/- 0.002）X射线管电流（毫安）（r（2）= 0.999）。CTDI 100 w随旋转时间线性增加：头部模式下，CTDI 100 w =（34.7 mGy/sec +/- 0.2）×旋转时间（秒）（r（2）= 1.0）;体部模式下，CTDI 100 w =（13.957 mGy/sec 0.005）×旋转时间（秒）（r（2）= 1.0）。标准化CTDI 100 w（毫戈瑞/100 mAs）与管电压的关系符合幂律：在头部模式下，CTDI 100 w = 0.00016 mGy/100 mAs（.）kVp +/-0.00007）X（管电压）（（2.5+/-0.1））（r（2）= 0.997）;在体模式下，CTD（100）w =（0.000012 mGy/100 mAs（.）kVp +/- 0.000007）×（管电压）（（2.8+/-0.1））（r（2）= 0.996）。在所有扫描模式中，CTDI 100 w随RPW的增加而减小。与制造商建议的值（显示在扫描仪控制台上）相比，CTDI 100 w在头部模式下高10%，在身体模式下低13%。当沉积功率超过24千瓦，CTDI 100 w增加了10%，由于使用的大focal spot.CONCLUSION：作者提供了一套表格的辐射剂量作为成像协议的函数，以促进实施辐射剂量效率的研究。((C))RSNA，2003年。
PURPOSE: To determine the dose characteristics of multi-detector row computed tomography (CT) and to provide tabulated dose values and rules of thumb that assist in minimizing the radiation dose at multi-detector row CT.MATERIALS AND METHODS: Weighted CT dose index, (CTDI100w) values were obtained from three multi-detector row CT scanners (LightSpeed; GE Medical Systems, Milwaukee, Wis) for both head and body CT modes by using standard CT-dose phantoms. The CTDI100w was determined as a function of x-ray tube voltage (80, 100, 120,140 kVp), tube current (range, 50-380 mA), tube rotation time (0.5-4.0 seconds), radiation profile width (RPW) (5, 10, 15, 20 mm), and acquisition mode.(helical high-quality and high-speed modes and axial one-, two-, and four-section modes). Statistical regression was performed to characterize the relationships between CTDI100w and various technique factors.RESULTS: The CTDI100w (milligray) increased linearly with tube current: in head mode, CTDI100w = (0.391 mGy/mA +/- 0.004) X tube current (milliampere) (r(2) = 0.999); in body mode, CTDI100w = (0.162 mGy/mA +/- 0.002) X tube current (millampere) (r(2) = 0.999). The CTDI100w increased linearly with rotation time: in head mode, CTDI100w = (34.7 mGy/sec +/- 0.2) X rotation time (seconds) (r(2) = 1.0); in body mode, CTDI100w = (13.957 mGy/sec 0.005) X rotation time (seconds) (r(2) = 1.0). The relationship of normalized CTDI100w (milligrays per 100 mAs) with tube voltage followed a power law: in head mode, CTDI100w = (0.00016 mGy/100 mAs (.) kVp +/-0.00007) X (tube voltage)((2.5+/-0.1)) (r(2) = 0.997); in body mode, CTD(100)w = (0.000012 mGy/100 mAs (.) kVp +/- 0.000007) X (tube voltage)((2.8+/-0.1)) (r(2) = 0.996). in all scanning modes, CTDI100w decreased when RPW increased. CTDI100w was 10% higher in head mode and 13% lower in body mode compared with the value suggested by the manufacturer, which is displayed at the scanner console. When deposited power exceeded 24 kW, CTDI100w increased by 10% as a result of use of the large focal spot.CONCLUSION: The authors provide a set of tables of radiation dose as a function of imaging protocol to facilitate implementation of radiation dose-efficient studies. ((C)) RSNA, 2003.