多层螺旋CT自动毫安技术对腰椎患者扫描剂量减少的可行性研究  

Feasibility of dose reduction in lumbar spine multi-slice CT examination with automatic tube current modulation

作　　者：郭濴[1] 葛英辉[1] 李剑颖[1] 程天明[1] 马千里[1] 

机构地区：[1]河南省人民医院放射科,郑州450003

出　　处：《中华放射学杂志》2009年第10期1092-1095,共4页Chinese Journal of Radiology

基　　金：河南省医学科技攻关计划项目（20030175）;河南省杰出青年科学基金（12120001300）

摘　　要：目的探讨MSCTZ轴自动毫安（ATCM）调制扫描技术对患者腰椎CT扫描剂量减少的可行性。方法对48例腰椎间盘突出症患者分椎间盘介入术前检查及术后复查2组，进行L3-S1相同覆盖范围MSCT检查。术前检查组采用常规固定320mAs（FM组），术后复查组采用噪声指数为12．0HU的Z轴ATCM技术（ATCM组）。分别选择L3～4、L4—5、L5-S1椎间盘平面作为观察平面，对2种毫安技术的图像质量、图像噪声和辐射剂量进行统计学分析。图像质量评分、辐射剂量比较采用配对t检验，图像噪声比较采用单因素方差分析。结果FM组的剂量长度乘积（DLP）平均为（273．4±45．4）mGy·cm，ATCM组为（187．9±66．4）mGy·cm，ATCM组比FM组降低31．3％（t：8．205，P〈0．05）；FM组的3个椎间盘平面图像噪声变异分别为（9．8±2．4）、（9．9±2．4）、（11．5±3．2）HU，ATCM组分别为（12．0±0．8）、（11．7±0．6）、（11．7±1．4）HU，ATCM组的图像噪声变异小于FM组（F=23．31，P〈0．05）；FM组3个椎间盘平面的图像质量评分分别为（4．7±0．3）、（4．5±0．2）、（4．5±0．2）分，ATCM组分别为（4．6±0．3）、（4．5±0．2）、（4．5±0．2）分，两组图像质量评分差异无统计学意义（t=1．000，P〉0．05）。结论使用噪声指数为12．0HU的ATCM技术，在保证图像质量的情况下可以降低辐射剂量约31．3％。Objective To investigate the feasibility of achieving consistent image quality with dose reduction technology in lumber spine MSCT examination with Z-axis automatic tube current modulation （ATCM）. Methods Forty-eight patients diagnosed as lumber intervertebral disc protrution scanned twice by MSCT before and after interventional operations with the same coverage from third lumbar vertebra to first sacral vertebra. The first scan （FM） was with fixed tube current of 320 mAs. The follow-up scan was with ATCM with noise index （NI） of 12. 0 HU. At the levels of L3-4, L4-5 and L5-S1, image quality, image noise and radiation dose were measured and analyzed. Image quality and radiation dose were compared by paired t-test and the image noise was compared by ANOVA test. Results The dosage of the ATCM had a 31.3% reduction compared with FM, the average DLP was （ 187. 9 ± 66. 4） mGy·cm and （273.4 ± 45.4） mGy·cm respectively, where t = 8. 205, P 〈 0. 05. The average noise and their deviations for the FM group were （9.8 ±2. 4） HU, （9.9±2. 4） HU, and （ 11.5± 3.2） HU at level of L3-4, L4-5, L5- S1, respectively. With ATCM, the average noise was （ 12. 0 ± 0. 8） HU, （ 11.7 ± 0. 6） HU, and （ 11.7±1.4） HU, respectively. There was statistical difference between the two groups （F = 23.31, P 〈 0. 05 ）. The image quality scores for the FM group were （4. 7 ±0. 3 ） , （ 4. 5 ±0. 2 ） , （ 4. 5 ± 0. 2 ） and showed no statistical difference to ATCM group （4. 6 ±0. 3） , （4. 5 ±0. 2）, （4.5 ±0. 2） at level of L3-4, L4-5, L5-S1, respectively, where t = 1. 000, P 〉 0. 05. Condusion ATCM technique with the noise index setting at 12. 0 HU can achieved a 31.3% dose reduction while keep the consistent image quality for lumbar spine MSCT study.

关 键 词：辐射剂量 腰椎 椎间盘移位 体层摄影术 X线计算机 

分 类 号：R686[医药卫生—骨科学]