摘要
目的探讨在儿童急诊头部CT平扫中,能谱扫描的单能量成像与常规扫描模式在图像质量与辐射剂量的对比,评价能谱成像改善图像质量的能力。方法选择进行急诊头部CT平扫的80例儿童患者,按照成像方式分为能谱成像组和常规成像组各40例。能谱成像组重建不同能级单能谱图像和混合能量图共8组图像。常规成像组固定管电压100 kVp,采用与能谱组相同的mAs扫描。测量各组图像三个兴趣区及背景区域的CT值和噪声值,计算各组图像相同区域组织的信噪比(Signal to Noise Ratio,SNR)及对比度信噪比(Contrast Signal to Noise Ratio,CNR),并对各组图像的整体质量进行盲法主观评分。各组数据比较采用方差分析,采用Kappa检验分析主观评分的一致性。结果随keV增加,测量区域CT值和噪声值逐渐降低,计算SNR值和CNR值,单能量组中65~80 keV组均高于混合能量组,更高于常规组,差异有统计学意义(P<0.001);主观评分单能量组中的65、70 keV优于混合能量成像及常规组(P<0.001);能谱成像组平均有效剂量较常规组降低(P<0.001)。结论儿童急诊头部CT平扫,使用能谱扫描模式,单能量成像尤其是65、70 keV成像能有效降低图像噪声,减少后颅窝及硬膜下伪影,图像质量有明显提高,且辐射剂量有所下降。
Objective To investigate the effect of monochromatic imaging on image quality and radiative agent in children’s emergency head CT plan scanning compared with conventional axial scanning,so as to evaluate the ability of energy spectrum imaging to improve image quality.Methods A total of 80 pediatric patients who underwent emergency head CT plan scan were divided into energy spectrum imaging group and conventional imaging group,40 cases in each group.The energy spectrum imaging group were reconstructed a total of 8 groups of monochromatic imaging on different energy levels and poly chromatic imaging.Conventional imaging group fixed tube voltage 100 kVp,and used the same mAs scanning as energy spectrum imaging group.CT value and Noise value of 3 region of interestand region of background in each group images were measured and recorded.Signalto-noise ratio(SNR)and contrast-to-noise ratio(CNR)of the same region organization of each group image were calculated.The overall quality of each group was scored by blind subjective method.Variance analysis and Kappa test were used to compare the data of each group and analyze the consistency of subjective scores.Results Within the increasing of keV,the CT value and noise value of the measured area gradually decreased in monochromatic imaging group.Calculating the SNR and CNR values,the 65 keV to 80 keV group in the monochromatic group was higher than that in the poly chromatic group,and higher than conventional group the difference was statistically significant(P<0.001).The subjective scores of 65 keV and 70 keV group were superior to those in the poly chromatic group and the conventional group(P<0.001).The mean effective dose of energy spectrum imaging group was lower than that of conventional group(P<0.001).Conclusion The children’s emergency brain CT plan scanning,using energy spectrum scanning mode,monochromatic imaging,especially 65 keV and 70 keV group,can effectively reduce total image noise,posterior fossa and subdural artifacts depressed.The image quality is improved and the radiation dose is decreased.
作者
陈锡建
曲海波
宁刚
李学胜
叶芷君
陈善慧
CHEN Xijian;QU Haibo;NING Gang;LI Xuesheng;YE Zhijun;CHEN Shanhui(Department of Radiology,West China Second University Hospital of Sichuan University,Chengdu Sichuan 610041,China;Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education(Sichuan University),Chengdu Sichuan 610041,China)
出处
《中国医疗设备》
2020年第10期91-95,共5页
China Medical Devices
关键词
计算机体层成像
X线
能谱成像
单能量成像
神经影像
computed tomography
X-ray
energy spectrum imaging
monochromatic imaging
neuro imaging
