低剂量CT成像质量控制检测实验研究
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摘要
目的对CT设备的性能进行质量控制检测,并确定符合国家标准的低剂量阈值。方法选取应用于临床的各种品牌型号的126台CT机,参考GB17985-2011《X射线计算机断层摄影装置质量保证检测规范》对CT值、噪声、高对比分辨力、低对比可探测能力等参数进行检测,并对数据进行统计分析。结果实验结果统计表明,120 kV常规mA量下,受检的CT设备的CT值、均匀性、高对比分辨力均合格。受检设备的CT值平均值±标准差为(-1.17±0.97)～(-1.33±0.67)HU;均匀性平均值±标准差为(1.17±0.17)～(1.33±0.67)HU;CT设备的噪声合格率为93.65%;CT设备的低对比分辨力合格率为96.03%。120 kV条件下,低于40 mAs时,噪声、低对比分辨力无法满足标准要求。结论对于国家标准来说,CT值、均匀性的数值标准过于宽松;噪声的检测间隔过长;CTDIw的数值标准过于严格。随着时代的发展,8～10 mm的层厚已不在临床采用;120 kV条件下,推荐40 mAs为CT低剂量检查的剂量阈值。
Objective To determine the low dose threshold that meets the national standard via performing quality control tests on the performance of the CT equipment. Methods A total of 126 CT machines of various brands and models applied in clinical practice were selected. The parameters such as CT value, noise, spatial resolution and low-contrast detectability were tested by referring to GB17985-2011 Specifications for quality assurance test for computed tomography X-ray scanners. Finally, the data were statistically analyzed. Results The experimental results showed that the CT value, uniformity and spatial resolution of the tested CT equipment were all quali?ed under 120 kV and normal mA. The mean ± standard deviation of CT value of the tested equipment was(-1.17±0.97) to(-1.33±0.67) HU. The mean ± standard of homogeneity was(1.17±0.17) to(1.33±0.67) HU. The noise quali?cation rate of CT equipment was 93.65%. The quali?ed rate of low contrast resolution of CT equipment was 96.03%. The noise and low contrast resolution could not meet the standard requirements under the condition of 120 kV and lower than 40 mAs.Conclusion For national standards, the numerical standards of CT value and uniformity are too loose, the noise detection interval is too long and the numerical standard of CTDIw is too strict. With the development of the times, 8 to 10 mm thick layer is no longer in clinical use. Under the condition of 120 kV, 40 mAs is recommended as the dose threshold for low-dose CT examination.
Objective To determine the low dose threshold that meets the national standard via performing quality control tests on the performance of the CT equipment. Methods A total of 126 CT machines of various brands and models applied in clinical practice were selected. The parameters such as CT value, noise, spatial resolution and low-contrast detectability were tested by referring to GB17985-2011 Specifications for quality assurance test for computed tomography X-ray scanners. Finally, the data were statistically analyzed. Results The experimental results showed that the CT value, uniformity and spatial resolution of the tested CT equipment were all quali?ed under 120 kV and normal mA. The mean ± standard deviation of CT value of the tested equipment was(-1.17±0.97) to(-1.33±0.67) HU. The mean ± standard of homogeneity was(1.17±0.17) to(1.33±0.67) HU. The noise quali?cation rate of CT equipment was 93.65%. The quali?ed rate of low contrast resolution of CT equipment was 96.03%. The noise and low contrast resolution could not meet the standard requirements under the condition of 120 kV and lower than 40 mAs.Conclusion For national standards, the numerical standards of CT value and uniformity are too loose, the noise detection interval is too long and the numerical standard of CTDIw is too strict. With the development of the times, 8 to 10 mm thick layer is no longer in clinical use. Under the condition of 120 kV, 40 mAs is recommended as the dose threshold for low-dose CT examination.
引文
[1]茹光腾,肖远球,成佛金,等.多层螺旋CT主要性能指标的探讨[J]影像诊断与介入放射学,2002,11(2):118-119.
[2]GB/T 17006.11-2015/IEC 61223-2-6:2016,医用成像部门的评价及例行试验第2-6部分:X射线计算机体层摄影设备成像性能稳定性试验[S].
[3]JJG 961-2017,医用诊断螺旋计算机断层摄影装置(CT)X射线辐射源[S].
[4]WS/T 391-2012,CT检查操作规程[S].
[5]李萍,余晓锷,杨克柽.CT的空间分辨力测量技术及测试体模研究[J].第一军医大学学报,2005,25(5):545-546.
[6]李庚.CT空间分辨率和低对比度分辨率的检测及其影响因素[A]中华医学会医学工程学分会学术年会暨中华临床医学工程及医疗信息化大会[C].2010.
[7]康立丽,余晓锷,冯晓刚.X-CT设备低对比度分辨力检测方法研究与分析[J].放射学实践,2003,18(5):318-320.
[8]杨克柽.C T值均匀性评价方法研究[J].中国测试,2 0 1 642(1):7-11.
[9]朱明,刘贵霞,李敬玉.CT扫描参数对CT值影响因素的实验研究[J].中国中西医结合影像学杂志,2017,15(4):473-475.
[10]白兴国,刘景鑫,周生岩.扫描参数影响螺旋CT图像质量的实验研究[J].长春中医学院学报,2003,19(2):38.
[11]GB17589-2011,X射线计算机断层摄影装置质量保证检测规范[S].
[12]李铁一,李辉,肖国文,等.胸部螺旋CT技术参数的最佳选择及应用[J].中华放射学杂志,1995,(12):829-833.
[13]杨克柽,林意群,冯晓刚.CT机应用质量检测与临床照片图像质量关系[J].放射学实践,2002,17(3):249-251.
[14]李萍,占杰,余晓锷.CT图像质量主要参数及其检测方法[J]放射学实践,2005,20(5):462-463.
[15]邹乾,胡军武.CT质量控制与放射防护分析[J].影像研究与医学应用,2017,1(8).
[16]赵照鹏,程全帅.浅谈医疗设备计量检定与质量检测[J].科学与财富,2018,(6):41.
[17]范荣,耿继武,黄伟旭,等.广东省CT机分布及使用现状[J].中华放射医学与防护杂志,2006,26(2):174-175.
[18]胡传朋,李永兴,程晓军,等.河南省放射诊疗设备性能检测结果分析[J].中华放射医学与防护杂志,2014,34(11):862-864.
[19]朱维杰,王新明,韩浚,等.基于北京市141台CT性能检测结果的差异分析与启示[J].中华放射医学与防护杂志,201838(6):439-442.
[20]高忠嵩,叶兆祥,张鹏,等.天津地区低剂量CT肺癌基线筛查与随访的初步临床分析[J].中国肿瘤临床,2017,44(20):1034-1039.
[21]宣志强,王强,应正巨,等.浙江省部分地区放射诊疗设备质量控制检测与分析[J].中华放射医学与防护杂志,201434(10):772-774.
[2]GB/T 17006.11-2015/IEC 61223-2-6:2016,医用成像部门的评价及例行试验第2-6部分:X射线计算机体层摄影设备成像性能稳定性试验[S].
[3]JJG 961-2017,医用诊断螺旋计算机断层摄影装置(CT)X射线辐射源[S].
[4]WS/T 391-2012,CT检查操作规程[S].
[5]李萍,余晓锷,杨克柽.CT的空间分辨力测量技术及测试体模研究[J].第一军医大学学报,2005,25(5):545-546.
[6]李庚.CT空间分辨率和低对比度分辨率的检测及其影响因素[A]中华医学会医学工程学分会学术年会暨中华临床医学工程及医疗信息化大会[C].2010.
[7]康立丽,余晓锷,冯晓刚.X-CT设备低对比度分辨力检测方法研究与分析[J].放射学实践,2003,18(5):318-320.
[8]杨克柽.C T值均匀性评价方法研究[J].中国测试,2 0 1 642(1):7-11.
[9]朱明,刘贵霞,李敬玉.CT扫描参数对CT值影响因素的实验研究[J].中国中西医结合影像学杂志,2017,15(4):473-475.
[10]白兴国,刘景鑫,周生岩.扫描参数影响螺旋CT图像质量的实验研究[J].长春中医学院学报,2003,19(2):38.
[11]GB17589-2011,X射线计算机断层摄影装置质量保证检测规范[S].
[12]李铁一,李辉,肖国文,等.胸部螺旋CT技术参数的最佳选择及应用[J].中华放射学杂志,1995,(12):829-833.
[13]杨克柽,林意群,冯晓刚.CT机应用质量检测与临床照片图像质量关系[J].放射学实践,2002,17(3):249-251.
[14]李萍,占杰,余晓锷.CT图像质量主要参数及其检测方法[J]放射学实践,2005,20(5):462-463.
[15]邹乾,胡军武.CT质量控制与放射防护分析[J].影像研究与医学应用,2017,1(8).
[16]赵照鹏,程全帅.浅谈医疗设备计量检定与质量检测[J].科学与财富,2018,(6):41.
[17]范荣,耿继武,黄伟旭,等.广东省CT机分布及使用现状[J].中华放射医学与防护杂志,2006,26(2):174-175.
[18]胡传朋,李永兴,程晓军,等.河南省放射诊疗设备性能检测结果分析[J].中华放射医学与防护杂志,2014,34(11):862-864.
[19]朱维杰,王新明,韩浚,等.基于北京市141台CT性能检测结果的差异分析与启示[J].中华放射医学与防护杂志,201838(6):439-442.
[20]高忠嵩,叶兆祥,张鹏,等.天津地区低剂量CT肺癌基线筛查与随访的初步临床分析[J].中国肿瘤临床,2017,44(20):1034-1039.
[21]宣志强,王强,应正巨,等.浙江省部分地区放射诊疗设备质量控制检测与分析[J].中华放射医学与防护杂志,201434(10):772-774.