西门子CT模拟机水的CT值和图像噪声的短期稳定性分析  

Analysis of Short-Term Stability of CT Number of Water,Image Noise and Tube Voltage for A SIEMENS CT-Simulator

作　　者：彭明洋 赵紫婷 时飞跃[3] 秦伟[3] 魏晓为[3] PENG Ming-yang;ZHAO Zi-ting;SHI Fei-yue;QIN Wei;WEI Xiao-wei(Department of Medical Radiology,Nanjing First Hospital,Nanjing Medical University,Nanjing 210006,Jiangsu Province,China;Department of Medical Equipment,Nanjing First Hospital,Nanjing Medical University,Nanjing 210006,Jiangsu Province,China;Radiation Therapy Center,Nanjing First Hospital,Nanjing Medical University,Nanjing 210006,Jiangsu Province,China)

机构地区：[1]南京医科大学附属南京医院(南京市第一医院)医学影像科,江苏南京210006 [2]南京医科大学附属南京医院(南京市第一医院)医疗设备处,江苏南京210006 [3]南京医科大学附属南京医院(南京市第一医院)肿瘤放疗中心,江苏南京210006

出　　处：《中国CT和MRI杂志》2022年第11期168-169,共2页Chinese Journal of CT and MRI

基　　金：江苏省自然科学基金面上项目(BK20181118)。

摘　　要：目的利用CT模拟机(西门子Sensation Open),分析水模体日常质量检测多次重复实验的结果,评价水的CT值和图像噪声的短期稳定性。方法使用与西门子CT模拟机配套的水模体,调用日常的检测质量(DQC)程序进行质控检测。DQC程序使用标称管电压120 kV和140 kV两种检测条件。通过质控检测,得到两种条件下水的CT值和图像噪声在30分钟内的10次检测数据,进行统计分析和比较研究。结果120kV条件,第1至6层(S1-S6)水的CT值(单位:HU)分别为:0.94±0.34,1.66±0.30,0.87±0.37,-0.83±0.34,0.3±0.42,0.29±0.45。140 kV条件,第1至6层水的CT值(单位:HU)分别为:-0.26±0.45,0.64±0.37,-0.14±0.31,-2.09±0.33,-1.33±0.34,-1.35±0.31。120kV与140kV条件第1至6层水的CT值在10次检测中的变化范围分别为(0.21~1.28)HU、(-1.23~-0.30)HU,第1次测量结果显著大于其余各次。120 kV和140 kV条件图像噪声(单位:HU)分别为10.23±0.03,9.37±0.04。结论由数据分析可见,该西门子CT模拟机水的CT值和图像噪声有较好的短期稳定性,但水的CT值在短时间内,随检测次数的增加呈下降趋势。Objective To evaluate the short-term stability of CT number of water and image noise for a SIEMENS CTsimulator,by analyzing the results of repeated experiments of daily quality check measurements using the water phantom.Methods The SIEMENS Sensation Open CT-simulator is tested 10 times within 30 minutes using a water phantom and the daily quality check(DQC)program,from which data of CT number of water and image noise for two cases with nominal tube voltages of 120 kV and 140 kV are obtained.Statistical analysis and comparison were conducted on the test data.Results In case 120 kV,data of CT number of water(unit:HU)for the 1st-6th slice are 0.94±0.34,1.66±0.3,0.87±0.37,-0.83±0.34,0.3±0.42,and 0.29±0.45 respectively;and in case 140 kV,corresponding values(unit:HU)are-0.26±0.45,0.64±0.37,-0.14±0.31,-2.09±0.33,-1.33±0.34,and-1.35±0.31 respectively.The deviation range of CT value of water in the two cases is(0.21~1.28)HU、(-1.23~-0.30)HU respectively,and the results of the first measurement are significantly greater than the others.In Case 120 kV and Case 140 kV,data of image noise are(10.23±0.03)HU and(9.37±0.04)HU respectively.Conclusions It can be seen from the statistical data that the SIEMENS CT-simulator in our department have good shortterm stability of CT number of water and image noise.But the CT number of water tends to decrease with the increase of short-interval test times.

关 键 词：CT模拟机 水的CT值 图像噪声 短期稳定性 

分 类 号：R445.3[医药卫生—影像医学与核医学]