摘要
目的:分析使用水模体进行日常质量检测得到的数据,评价西门子Sensation Open CT模拟机水的CT值、图像噪声和管电压的长期稳定性。方法:使用水模体,调用日常质量检测程序,每月检测西门子Sensation Open CT模拟机,得到标称管电压120和140 kV两种情形水的CT值、图像噪声和管电压的检测数据。对2013年7月~2016年4月共34个月的检测数据进行统计分析。结果:120 kV情形:第1~6层(层厚4.8 mm)水的CT值分别为:(0.05±0.47)、(0.75±0.36)、(0.08±0.50)、(-1.21±0.46)、(-0.53±0.45)、(-0.62±0.45)HU。140 kV情形:第1~6层水的CT值分别为:(0.07±0.50)、(1.01±0.42)、(0.11±0.41)、(-1.36±0.51)、(-1.24±0.38)、(-1.01±0.45)HU。120和140 kV两种情形的图像噪声分别为(10.32±0.05)、(9.42±0.06)HU。标称管电压120 kV情形,检测到管电压值119.8 kV 28次,120.0 kV 6次;标称管电压140 kV情形,检测到管电压值139.8 kV 18次,139.6 kV 16次。结论:由统计数据可见,在34个月中,该西门子CT模拟机水的CT值、图像噪声和管电压比较稳定,满足使用要求。
Objective To evaluate the long-term stability of the CT number of water, image noise and tube voltage for a SIEMENS Sensation Open CT-simulator by analyzing the data from routine quality assurance measurements using water phantom. Methods SIEMENS Sensation Open CT-simulator was tested monthly by a water phantom and routine quality assurance program. We obtained the CT number of water, image noise and tube voltage when the nominal tube voltages was120 or 140 kV. Statistical analysis was conducted on the test data of 34 months from July 2013 to April 2016. Results At the nominal tube voltages of 120 kV, the CT number of water for the first to the sixed slice(slice thickness: 4.8 mm) were(0.05±0.47),(0.75±0.36),(0.08±0.50),(-1.21±0.46),(-0.53±0.45) and(-0.62±0.45) HU, respectively; and at 140 kV, the corresponding CT number of water for six slices were(0.07±0.50),(1.01±0.42),(0.11±0.41),(-1.36±0.51),(-1.24±0.38) and(-1.01 ±0.45) HU, respectively. The image noises at the nominal tube voltages of 120 and 140 kV were(10.32±0.05) and(9.42±0.06) HU. When the nominal tube voltage was 120 kV, we detected 28 times of 119.8 kV(tube voltage) and 6 times of 120.0 kV; when the nominal tube voltage was 140 kV, we detected 18 times of 139.8 kV and 16 times of 139.6 kV.Conclusion The statistical data shows that in the 34 months, the CT number of water, image noise and tube voltage for SIEMENS CT-simulator are stable and meet the operating requirements.
出处
《中国医学物理学杂志》
CSCD
2017年第12期1232-1235,共4页
Chinese Journal of Medical Physics
基金
江苏省高校自然科学研究面上项目(15KJB360004)